fix: Case chang

* master:

.eslintignore

@@ -0,0 +1,8 @@
+docs/**
+.svelte-kit/**
+static/**
+build/**
+node_modules/**
+coverage/**
+__snapshots__/**
+snapshots.js

.eslintrc.cjs

@@ -1,48 +1,50 @@
 module.exports = {
-	root: true,
-	parser: '@typescript-eslint/parser',
-	extends: [
-		'eslint:recommended',
-		'plugin:@typescript-eslint/recommended',
-		// 'plugin:@typescript-eslint/recommended-requiring-type-checking',
-		'prettier'
-	],
-	plugins: ['svelte3', 'tailwindcss', '@typescript-eslint', 'es'],
-	ignorePatterns: [
-		'docs/*',
-		'*.cjs',
-		'*.md',
-		'snapshots.js',
-		'svelte.config.js',
-		'renovate.json',
-		'package.json',
-		'tsconfig.json'
-	],
-	overrides: [{ files: ['*.svelte'], processor: 'svelte3/svelte3' }],
-	settings: {
-		'svelte3/typescript': () => require('typescript')
-	},
-	parserOptions: {
-		sourceType: 'module',
-		ecmaVersion: 2019,
-		tsconfigRootDir: __dirname,
-		project: ['./tsconfig.json'],
-		extraFileExtensions: ['.svelte']
-	},
-	env: {
-		browser: true,
-		es2017: true,
-		node: true
-	},
-	rules: {
-		'@typescript-eslint/ban-ts-comment': [
-			'error',
-			{
-				'ts-ignore': 'allow-with-description'
-			}
-		],
-		'@typescript-eslint/no-unsafe-member-access': 'off',
-		'@typescript-eslint/no-unsafe-assignment': 'off',
-		'es/no-regexp-lookbehind-assertions': 'error'
-	}
+  root: true,
+  parser: '@typescript-eslint/parser',
+  extends: [
+    'eslint:recommended',
+    'plugin:@typescript-eslint/recommended',
+    // 'plugin:@typescript-eslint/recommended-requiring-type-checking',
+    'prettier'
+  ],
+  plugins: ['svelte3', 'tailwindcss', '@typescript-eslint', 'es', 'vitest'],
+  ignorePatterns: [
+    'docs/*',
+    '*.cjs',
+    '*.js',
+    '*.md',
+    'snapshots.js',
+    'svelte.config.js',
+    'renovate.json',
+    'package.json',
+    'tsconfig.json'
+  ],
+  overrides: [{ files: ['*.svelte'], processor: 'svelte3/svelte3' }],
+  settings: {
+    'svelte3/typescript': () => require('typescript')
+  },
+  parserOptions: {
+    sourceType: 'module',
+    ecmaVersion: 2020,
+    tsconfigRootDir: __dirname,
+    project: ['./tsconfig.json'],
+    extraFileExtensions: ['.svelte'],
+    allowAutomaticSingleRunInference: true
+  },
+  env: {
+    browser: true,
+    es2020: true
+  },
+  rules: {
+    '@typescript-eslint/ban-ts-comment': [
+      'error',
+      {
+        'ts-ignore': 'allow-with-description'
+      }
+    ],
+    '@typescript-eslint/no-unsafe-member-access': 'off',
+    '@typescript-eslint/no-unsafe-assignment': 'off',
+    'es/no-regexp-lookbehind-assertions': 'error',
+    curly: ['error', 'all']
+  }
 };

.git-blame-ignore-revs

@@ -0,0 +1,5 @@
+# .git-blame-ignore-revs
+# Prettier Pass
+6fde9e22a3ba0b80879a1909fb233367ef20b738
+# Tabs -> Spaces
+0ac606b8fbf6f94215cbda1d4511e2dcd30e4655

.github/FUNDING.yml

@@ -0,0 +1 @@
+github: [sidharthv96, knsv]

.github/workflows/codeql-analysis.yml

@@ -35,11 +35,11 @@ jobs:
 
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v2
+        uses: actions/checkout@v3
 
       # Initializes the CodeQL tools for scanning.
       - name: Initialize CodeQL
-        uses: github/codeql-action/init@v1
+        uses: github/codeql-action/init@v2
         with:
           config-file: ./.github/codeql/config.yml
           languages: ${{ matrix.language }}
@@ -65,4 +65,4 @@ jobs:
       #   make release
 
       - name: Perform CodeQL Analysis
-        uses: github/codeql-action/analyze@v1
+        uses: github/codeql-action/analyze@v2

.github/workflows/deploy.yml

@@ -12,7 +12,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout
-        uses: actions/checkout@v2
+        uses: actions/checkout@v3
 
       - uses: actions/setup-node@v3
         with:
@@ -21,16 +21,12 @@ jobs:
 
       - name: Build & Deploy
         run: |
-          npm i -g yarn
           export DEPLOY=true
-          [ "$GITHUB_EVENT_NAME" == "pull_request" ] && export BETA=true && rm -rf docs/beta/
           [ "$GITHUB_EVENT_NAME" != "pull_request" ] && rm -rf docs/_app/
           yarn install
-          yarn run lint
           version=$(yarn version --patch --no-git-tag-version | grep "New version" | cut -d':' -f 2)
           yarn build
-          cd bin
-          ./fix-path
+          yarn run lint
           cd ..
 
       - name: Deploy

.github/workflows/docker-publish.yml

@@ -24,7 +24,7 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v3
 
       - name: Run tests
         run: |
@@ -38,7 +38,7 @@ jobs:
     if: github.event_name == 'push'
 
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v3
 
       - name: Build image
         run: docker build . --file Dockerfile --tag $IMAGE_NAME

.github/workflows/stale.yml

@@ -8,10 +8,13 @@ jobs:
   stale:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/stale@v4
+      - uses: actions/stale@v6
         with:
           repo-token: ${{ secrets.GITHUB_TOKEN }}
           exempt-issue-labels: 'retained'
           exempt-pr-labels: 'retained'
-          stale-issue-message: 'This issue is stale because it has been open 30 days with no activity. Remove stale label or comment or this will be closed in 7 days'
-          stale-pr-message: 'This pr is stale because it has been open 30 days with no activity. Remove stale label or comment or this will be closed in 7 days'
+          stale-issue-message: 'This issue is stale because it has been open 90 days with no activity. Remove stale label or comment or this will be closed in 30 days'
+          stale-pr-message: 'This pr is stale because it has been open 90 days with no activity. Remove stale label or comment or this will be closed in 30 days'
+          days-before-stale: 90
+          days-before-close: 30
+          days-before-pr-close: -1

.github/workflows/tests.yml

@@ -1,4 +1,4 @@
-name: Cypress Tests
+name: Tests
 
 on:
   pull_request:
@@ -9,14 +9,17 @@ on:
 jobs:
   cypress-run:
     runs-on: ubuntu-latest
-    # Update after https://github.com/cypress-io/cypress-docker-images/issues/487
-    container: cypress/browsers:node14.16.0-chrome90-ff88
+    strategy:
+      fail-fast: false
+      matrix:
+        # run 3 copies of the current job in parallel
+        containers: [1, 2, 3]
 
     steps:
       - name: Checkout
-        uses: actions/checkout@v2
+        uses: actions/checkout@v3
 
-      - uses: actions/cache@v2
+      - uses: actions/cache@v3
         id: yarn-and-build-cache
         with:
           path: |
@@ -27,20 +30,22 @@ jobs:
           restore-keys: |
             ${{ runner.os }}-node_modules-build-
 
-      - name: Lint
-        run: |
-          yarn install
-          yarn run lint
+      - uses: actions/setup-node@v3
+        with:
+          node-version: 16
+          cache: 'yarn'
 
       # Install NPM dependencies, cache them correctly
       # and run all Cypress tests
       - name: Cypress run
-        uses: cypress-io/github-action@v2
+        uses: cypress-io/github-action@v3
         with:
           build: yarn build
           start: yarn preview
           wait-on: 'http://localhost:3000'
           record: true
           headless: true
+          parallel: true
         env:
           CYPRESS_RECORD_KEY: ${{ secrets.CYPRESS_RECORD_KEY }}
+          CYPRESS_CI: true

.github/workflows/unit-tests.yml

@@ -0,0 +1,36 @@
+name: Unit Tests
+
+on:
+  pull_request:
+    branches:
+      - master
+      - develop
+
+jobs:
+  unit-tests:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v3
+
+      - uses: actions/cache@v3
+        id: yarn-and-build-cache
+        with:
+          path: |
+            build
+            node_modules
+          key: ${{ runner.os }}-node_modules-build-${{ hashFiles('**/yarn.lock') }}
+          restore-keys: |
+            ${{ runner.os }}-node_modules-build-
+
+      - uses: actions/setup-node@v3
+        with:
+          node-version: 16
+          cache: 'yarn'
+
+      - name: Lint & Test
+        run: |
+          yarn install
+          yarn lint
+          yarn test:unit

.github/workflows/update-browserlist.yml

@@ -1,15 +1,17 @@
 name: Update Browserslist
 on:
-  workflow_dispatch:
-
+  push:
+    branches-ignore:
+      - 'develop'
+      - 'master'
 jobs:
   build:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v3
       - run: npx browserslist@latest --update-db
       - name: Commit changes
-        uses: EndBug/add-and-commit@v8
+        uses: EndBug/add-and-commit@v9
         with:
           author_name: ${{ github.actor }}
           author_email: ${{ github.actor }}@users.noreply.github.com

.github/workflows/update-monaco-editor.yml

@@ -9,10 +9,16 @@ jobs:
   build:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v2
-      - run: ./bin/update-monaco
+      - uses: actions/checkout@v3
+      - uses: actions/setup-node@v3
+        with:
+          node-version: 18
+      - name: Update monaco version
+        run: |
+          yarn install
+          node ./bin/update-monaco.js
       - name: Commit changes
-        uses: EndBug/add-and-commit@v8
+        uses: EndBug/add-and-commit@v9
         with:
           author_name: ${{ github.actor }}
           author_email: ${{ github.actor }}@users.noreply.github.com

.gitignore

@@ -9,5 +9,6 @@ yarn-error.log
 /build
 /functions
 /snapshots.js
+/cypress/downloads
 /cypress/videos
 /cypress/screenshots

.prettierignore

@@ -3,4 +3,6 @@ docs/**
 static/**
 build/**
 node_modules/**
+coverage/**
+__snapshots__/**
 snapshots.js

.prettierrc

@@ -1,8 +1,7 @@
 {
-	"singleQuote": true,
-	"svelteSortOrder": "options-scripts-markup-styles",
-	"bracketSameLine": true,
-	"useTabs": true,
-	"trailingComma": "none",
-	"printWidth": 100
+  "singleQuote": true,
+  "svelteSortOrder": "options-scripts-markup-styles",
+  "bracketSameLine": true,
+  "trailingComma": "none",
+  "printWidth": 100
 }

.vscode/launch.json

@@ -0,0 +1,15 @@
+{
+  // Use IntelliSense to learn about possible attributes.
+  // Hover to view descriptions of existing attributes.
+  // For more information, visit: https://go.microsoft.com/fwlink/?linkid=830387
+  "version": "0.2.0",
+  "configurations": [
+    {
+      "type": "pwa-chrome",
+      "request": "launch",
+      "name": "Launch Chrome against localhost",
+      "url": "http://localhost:3000",
+      "webRoot": "${workspaceFolder}"
+    }
+  ]
+}

.vscode/settings.json

@@ -1,4 +1,9 @@
 {
-	"editor.formatOnSave": true,
-	"cSpell.words": ["pako", "Serde", "serdes"]
+  "editor.formatOnSave": true,
+  "cSpell.words": ["asyncable", "mindmap", "pako", "Serde", "serdes"],
+  "vitest.commandLine": "yarn test:unit",
+  "vitest.enable": true,
+  "testing.autoRun.mode": "rerun",
+  "svelte.enable-ts-plugin": true,
+  "githubPullRequests.ignoredPullRequestBranches": ["develop"]
 }

Dockerfile

@@ -6,11 +6,12 @@
 # Stop               : press ctrl + c 
 #                                     or 
 #                                        docker stop mermaid-live-editor
-FROM node:17.6.0 as mermaid-live-editor-builder 
+FROM node:18.12.0 as mermaid-live-editor-builder 
 COPY --chown=node:node . /home
 WORKDIR /home
 RUN yarn install
 RUN yarn build
 
 FROM nginx:alpine as mermaid-live-editor-runner
+COPY ./nginx.conf /etc/nginx/conf.d/default.conf
 COPY --from=mermaid-live-editor-builder --chown=nginx:nginx /home/docs /usr/share/nginx/html

Dockerfile.dev

@@ -1,4 +1,4 @@
-FROM node:17
+FROM node:18
 WORKDIR /app
 COPY package.json .
 COPY yarn.lock .

SECURITY.md

@@ -0,0 +1,13 @@
+# Security Policy
+
+## Supported Versions
+
+Live editor only has a single version, which will be maintained.
+
+| Version | Supported          |
+| ------- | ------------------ |
+| latest  | :white_check_mark: |
+
+## Reporting a Vulnerability
+
+To report a vulnerability, please e-mail security@mermaid.live with a description of the issue, the steps you took to create the issue, affected versions, and if known, mitigations for the issue.

bin/update-monaco

@@ -1,12 +0,0 @@
-#!/bin/bash
-
-monacoVersion="$(jq -r '.dependencies."monaco-editor"' package.json)"
-monacoVersion="${monacoVersion:1}"
-
-if [[ $(uname) == "Darwin" ]]; 
-then
-    sed -i '' -E "s/monaco-editor\/[^/]*/monaco-editor\/$monacoVersion/g" ./src/app.html
-else
-    sed -i'' -E "s/monaco-editor\/[^/]*/monaco-editor\/$monacoVersion/g" ./src/app.html
-fi
-

bin/update-monaco.js

@@ -0,0 +1,45 @@
+import fs from 'fs';
+import path from 'path';
+import { parse } from 'node-html-parser';
+import prettier from 'prettier';
+
+// parse monaco version out of package.json
+const packageJson = JSON.parse(fs.readFileSync('package.json'));
+const monacoVersion = packageJson.dependencies['monaco-editor'].replace('^', '');
+
+// fetch monaco sri info from cdnjs api
+const cdnjsAPIResp = await fetch(
+  `https://api.cdnjs.com/libraries/monaco-editor/${monacoVersion}?fields=sri`
+);
+if (cdnjsAPIResp.ok) {
+  const respJson = await cdnjsAPIResp.json();
+  const htmlPath = path.join('src', 'app.html');
+  const appHtml = fs
+    .readFileSync(htmlPath, 'utf8')
+    // update monaco version of every asset in app.html
+    .replaceAll(/[0-9.]+\/min\/vs/g, `${monacoVersion}/min/vs`);
+  const root = parse(appHtml);
+  const updateIntegrity = (tag, attr) => {
+    for (const node of root
+      .getElementsByTagName(tag)
+      .filter((node) => node.getAttribute(attr)?.includes('monaco-editor'))) {
+      const file = node.getAttribute(attr).split(`${monacoVersion}/`)[1];
+      node.setAttribute('integrity', respJson.sri[file]);
+    }
+  };
+
+  updateIntegrity('script', 'src');
+  updateIntegrity('link', 'href');
+
+  fs.writeFileSync(
+    htmlPath,
+    prettier.format(root.toString(), {
+      singleQuote: false,
+      parser: 'html',
+      bracketSameLine: true,
+      useTabs: true
+    })
+  );
+} else {
+  throw Error('Unable to fetch monaco sri data from cdnjs api.');
+}

cypress.config.js

@@ -0,0 +1,35 @@
+import { defineConfig } from 'cypress';
+import fs from 'fs';
+import { isFileExist, findFiles } from 'cy-verify-downloads';
+export default defineConfig({
+  projectId: '2ckppp',
+  viewportWidth: 1440,
+  viewportHeight: 768,
+  snapshotFileName: './cypress/snapshots.js',
+  defaultCommandTimeout: 16000,
+  requestTimeout: 16000,
+  retries: {
+    runMode: 4,
+    openMode: 0
+  },
+  e2e: {
+    setupNodeEvents(on, config) {
+      on('task', {
+        isFileExist,
+        findFiles,
+        deleteFile(path) {
+          fs.rmSync(path);
+          return null;
+        },
+        readFileMaybe(filename) {
+          if (fs.existsSync(filename)) {
+            return fs.readFileSync(filename, 'utf8');
+          }
+          return null;
+        }
+      });
+    },
+    baseUrl: 'http://localhost:3000',
+    specPattern: 'cypress/e2e/**/*.spec.ts'
+  }
+});

cypress.json

@@ -1,11 +0,0 @@
-{
-	"projectId": "2ckppp",
-	"$schema": "https://on.cypress.io/cypress.schema.json",
-	"baseUrl": "http://localhost:3000",
-	"pluginsFile": "./cypress/plugins/index.cjs",
-	"viewportWidth": 1440,
-	"viewportHeight": 768,
-	"snapshotFileName": "./cypress/snapshots.js",
-	"defaultCommandTimeout": 16000,
-	"requestTimeout": 16000
-}

cypress/.eslintrc

@@ -1,12 +1,10 @@
 {
-	"plugins": ["cypress", "mocha"],
-	"extends": ["plugin:cypress/recommended", "plugin:mocha/recommended"],
-	"rules": {
-		"jest/expect-expect": "off",
-		"mocha/no-mocha-arrows": "off"
-	},
-	"env": {
-		"cypress/globals": true,
-		"mocha": true
-	}
+  "plugins": ["cypress"],
+  "extends": ["plugin:cypress/recommended"],
+  "rules": {
+    "jest/expect-expect": "off"
+  },
+  "env": {
+    "cypress/globals": true
+  }
 }

cypress/e2e/actions.spec.ts

@@ -0,0 +1,48 @@
+import { verifyFileSize } from './util';
+describe('Check actions', () => {
+  beforeEach(() => {
+    cy.clearLocalStorage();
+    cy.visit('/edit');
+  });
+
+  it('should update markdown code', () => {
+    cy.get('#markdown')
+      .invoke('val')
+      .then((oldText) => {
+        cy.get('#editor').click('bottom').type('{enter}C --> HistoryTest');
+        cy.get('#markdown')
+          .invoke('val')
+          .then((newText) => {
+            expect(oldText).to.not.eq(newText);
+          });
+      });
+  });
+
+  it('should load gists from URL', () => {
+    cy.get('#gist').type('https://gist.github.com/sidharthv96/6268a23e673a533dcb198f241fd7012a');
+    cy.contains('Load Gist').click();
+    cy.contains('Go shopping!!');
+  });
+
+  it('should download png and svg', () => {
+    cy.clock(new Date(2022, 0, 1).getTime());
+
+    cy.get(`#downloadPNG`).click();
+    verifyFileSize('diagram', 'png', 21_000);
+
+    cy.get(`#downloadSVG`).click();
+    verifyFileSize('diagram', 'svg', 10_000);
+
+    // Verify downloaded file is different for different diagrams
+    cy.contains('Sample Diagrams').click();
+    cy.contains('ER').click();
+
+    cy.get(`#downloadPNG`).click();
+    verifyFileSize('diagram', 'png', 46_000);
+
+    cy.get(`#downloadSVG`).click();
+    verifyFileSize('diagram', 'svg', 12_000);
+
+    cy.clock().invoke('restore');
+  });
+});

cypress/e2e/diagramUpdate.spec.ts

@@ -0,0 +1,86 @@
+import { getEditor, cmd } from './util';
+
+describe('Auto sync tests', () => {
+  beforeEach(() => {
+    cy.clearLocalStorage();
+    cy.visit('/');
+  });
+
+  it('should dim diagram when code is edited', () => {
+    cy.contains('Auto sync').click();
+    cy.get('#view').should('not.have.class', 'outOfSync');
+    cy.get('#errorContainer').should('not.exist');
+    getEditor({ bottom: true, newline: true }).type('  C --> Test');
+    cy.get('#view').should('have.class', 'outOfSync');
+    cy.get('#errorContainer').should('contain.text', 'Diagram out of sync.');
+    cy.getLocalStorage('codeStore').snapshot();
+  });
+
+  it('should update diagram when shortcut is used', () => {
+    cy.contains('Auto sync').click();
+    cy.get('#view').should('not.have.class', 'outOfSync');
+    getEditor().type('  C --> Test');
+    cy.get('#view').should('have.class', 'outOfSync');
+    cy.get('#errorContainer').should('contain.text', 'Diagram out of sync.');
+    getEditor().type(`${cmd}{enter}`);
+    cy.get('#errorContainer').should('not.exist');
+    cy.get('#view').should('not.have.class', 'outOfSync');
+  });
+
+  it('should show/hide sync button with auto sync', () => {
+    cy.get('[data-cy=sync]').should('not.exist');
+    cy.contains('Auto sync').click();
+    cy.get('[data-cy=sync]').should('exist');
+    cy.get('#autoSync').check();
+    cy.get('[data-cy=sync]').should('not.exist');
+  });
+
+  it('should not dim diagram when code is in sync', () => {
+    cy.contains('Auto sync').click();
+    cy.get('#view').should('not.have.class', 'outOfSync');
+    getEditor().type('  C --> Test');
+    cy.get('#view').should('have.class', 'outOfSync');
+    cy.get('[data-cy=sync]').click();
+    cy.get('#view').should('not.have.class', 'outOfSync');
+    cy.get('#autoSync').check();
+    getEditor().type('ing');
+    cy.get('#view').should('not.have.class', 'outOfSync');
+    cy.getLocalStorage('codeStore').snapshot();
+  });
+
+  it('supports commenting code out/in', () => {
+    getEditor().type(`{uparrow}${cmd}/`);
+    cy.get('#view').contains('Car').should('not.exist');
+
+    getEditor().type(`{uparrow}${cmd}/`);
+    cy.get('#view').contains('Car').should('exist');
+  });
+
+  it('supports editing code when code is incorrect', () => {
+    cy.visit(
+      '/edit#pako:eNpljjEKwzAMRa8SNOcEnlt6gK5eVFvYJsgOqkwpIXevg9smEE1PnyfxF3DFExgISW-CczQ2D21cYU7a-SGYXRwyvTp9jUhuKlVP-eHy7zA-leQsMEmg_QOM0BLG5FujZVMsaCQmC6ahR5ks2Lw2r84ela4-aREwKpVGwKrl_s7ut3fnkjAIcg_XDzuaUhs'
+    );
+    cy.get('#errorContainer').should('not.exist');
+    getEditor({ newline: true }).type(`branch test`);
+    cy.get('#editor').contains('branch test').should('exist');
+    cy.get('#errorContainer')
+      .contains(
+        'Error: Trying to checkout branch which is not yet created. (Help try using "branch master")'
+      )
+      .should('exist');
+  });
+});
+
+describe('Pan and Zoom', () => {
+  beforeEach(() => {
+    cy.clearLocalStorage();
+    cy.visit('/');
+  });
+  it('should toggle pan and zoom', () => {
+    cy.get('#svg-pan-zoom-reset-pan-zoom').should('not.exist');
+    cy.contains('Pan & Zoom').click();
+    cy.get('#svg-pan-zoom-reset-pan-zoom').should('exist');
+    cy.contains('Pan & Zoom').click();
+    cy.get('#svg-pan-zoom-reset-pan-zoom').should('not.exist');
+  });
+});

cypress/e2e/docMap.spec.ts

@@ -0,0 +1,36 @@
+describe('Editor docs tests', () => {
+  beforeEach(() => {
+    cy.on('uncaught:exception', () => {
+      return false;
+    });
+    cy.clearLocalStorage();
+    cy.visit('/edit');
+    cy.contains('Sample Diagrams').click();
+  });
+
+  it('Test default loading', () => {
+    cy.get(`[data-cy=docs][href^="https://mermaid-js.github.io/mermaid"]`).should('exist');
+  });
+
+  it('Test to see if the correct URL loads when changing from one diagram to other', () => {
+    cy.contains('Flow').click();
+    cy.get(`[data-cy=docs][href$="/#/flowchart"]`).should('exist');
+
+    cy.contains('Config').click();
+    cy.get(`[data-cy=docs][href$="/#/flowchart?id=configuration"]`).should('exist');
+
+    cy.contains('Sequence').click();
+    cy.get(`[data-cy=docs][href$="/#/sequenceDiagram?id=configuration"]`).should('exist');
+
+    cy.contains('Code').click();
+    cy.get(`[data-cy=docs][href$="/#/sequenceDiagram"]`).should('exist');
+  });
+
+  it("Test to check URLs for a case where config URL doesn't exist", () => {
+    cy.contains('State').click();
+    cy.get(`[data-cy=docs][href$="/#/stateDiagram"]`).should('exist');
+
+    cy.contains('Config').click();
+    cy.get(`[data-cy=docs][href$="/#/stateDiagram"]`).should('exist');
+  });
+});

cypress/e2e/history.spec.ts

@@ -0,0 +1,105 @@
+import { getEditor, verifyFileSnapshot } from './util';
+
+describe('Save History', () => {
+  beforeEach(() => {
+    cy.clock(new Date(2022, 0, 1).getTime());
+    cy.clearLocalStorage();
+    cy.visit('/edit');
+
+    cy.contains('Actions').click();
+    cy.contains('History').click();
+  });
+
+  afterEach(() => {
+    cy.clock().invoke('restore');
+  });
+
+  it('should load history from localstorage', () => {
+    cy.setLocalStorage(
+      'manualHistoryStore',
+      '[{"state":{"code":"graph TD\\n    A[Halloween] -->|Get money| B(Go shopping)","mermaid":"{\\n  \\"theme\\": \\"dark\\"\\n}","autoSync":true,"updateDiagram":false},"time":0,"type":"manual","id":"d7ea820e-21dd-418a-b984-fd58acde09df","name":"hollow-art"},{"state":{"code":"graph TD\\n    A[Christmas] -->|Get money| B(Go shopping)","mermaid":"{\\n  \\"theme\\": \\"dark\\"\\n}","autoSync":true,"updateDiagram":true},"time":0,"type":"manual","id":"b749ffc6-522b-4a44-86cf-7c1ffc3146b3","name":"helpful-ocean"}]'
+    );
+    cy.setLocalStorage(
+      'autoHistoryStore',
+      '[{"state":{"code":"graph TD\\n    A[New Year] -->|Get money| B(Go shopping)","mermaid":"{\\n  \\"theme\\": \\"dark\\"\\n}","autoSync":true,"updateDiagram":false},"time":0,"type":"auto","id":"69ea820e-522b-4a44-86cf-fd58acde09df","name":"barking-dog"},{"state":{"code":"graph TD\\n    A[Christmas] -->|Get money| B(Go shopping)","mermaid":"{\\n  \\"theme\\": \\"dark\\"\\n}","autoSync":true,"updateDiagram":true},"time":0,"type":"manual","id":"x749ffc6-21dd-418a-b984-7c1ffc3146b3","name":"needy-mosquito"}]'
+    );
+    cy.reload();
+    cy.contains('Actions').click();
+    cy.contains('History').click();
+    cy.get('#historyList').find('li').should('have.length', 2);
+    cy.get('#historyList').find('No items in History').should('not.exist');
+    cy.get('#historyList').contains('helpful-ocean');
+    cy.get('#historyList').contains('hollow-art');
+    cy.contains('Restore').click();
+    cy.contains('Halloween');
+    cy.contains('Timeline').click();
+
+    cy.get('#historyList').find('li').should('have.length', 2);
+    cy.get('#historyList').find('No items in History').should('not.exist');
+    cy.get('#historyList').contains('needy-mosquito');
+    cy.get('#historyList').contains('barking-dog');
+    cy.contains('Restore').click();
+    cy.contains('New Year');
+  });
+
+  it('should save when clicked', () => {
+    cy.get('#historyList').find('li').should('have.length', 0);
+    cy.get('#historyList').contains('No items in History');
+    cy.get('#saveHistory').click();
+    cy.get('#historyList').find('No items in History').should('not.exist');
+    cy.get('#historyList').find('li').should('have.length', 1);
+    cy.get('#saveHistory').click();
+    cy.on('window:alert', (str) => {
+      expect(str).to.equal('State already saved.');
+    });
+    cy.on('window:confirm', () => true);
+    getEditor().type('  C --> HistoryTest');
+    cy.get('#saveHistory').click();
+    cy.get('#historyList').find('li').should('have.length', 2);
+  });
+
+  it('should be able to restore and delete', () => {
+    cy.get('#saveHistory').click();
+    getEditor().type('  C --> HistoryTest');
+    cy.get('#historyList').find('No items in History').should('not.exist');
+    cy.get('#historyList').find('li').should('have.length', 1);
+    cy.contains('HistoryTest');
+    cy.contains('Restore').click();
+    cy.contains('HistoryTest').should('not.exist');
+    cy.contains('Delete').click();
+    cy.get('#historyList').find('li').should('have.length', 0);
+    cy.get('#historyList').contains('No items in History');
+    cy.get('#saveHistory').click();
+    getEditor().type('  C --> HistoryTest');
+    cy.get('#saveHistory').click();
+    cy.get('#editor').type('ing');
+    cy.get('#clearHistory').click();
+    cy.on('window:alert', (str) => {
+      expect(str).to.equal('Clear all saved items?');
+    });
+    cy.on('window:confirm', () => true);
+    cy.get('#historyList').contains('No items in History');
+  });
+
+  // TODO: Fix #639
+  xit('should auto save history', () => {
+    getEditor().type('  C --> HistoryTest');
+    cy.tick(70000);
+    cy.contains('Timeline').click();
+    cy.get('#historyList').find('li').should('have.length', 1);
+    cy.get('#editor').type('ing');
+    cy.tick(70000);
+    cy.get('#historyList').find('li').should('have.length', 2);
+    for (let i = 0; i < 31; i++) {
+      cy.get('#editor').type('.');
+      cy.tick(70000);
+    }
+    cy.get('#historyList').find('li').should('have.length', 30);
+  });
+
+  it('should download history', () => {
+    cy.get('#saveHistory').click();
+    cy.get(`#downloadHistory`).click();
+    verifyFileSnapshot('history', 'json', 'A[Christmas] -->|Get money| B(Go shopping)');
+  });
+});

cypress/e2e/loadSite.spec.ts

@@ -0,0 +1,122 @@
+import { toBase64 } from 'js-base64';
+
+describe('Site Loads', () => {
+  beforeEach(() => {
+    cy.clearLocalStorage();
+    cy.visit('/');
+  });
+
+  it('Check Home page load', () => {
+    cy.url().should('include', '/edit');
+    cy.contains('History').click();
+    cy.getLocalStorage('codeStore').snapshot();
+  });
+
+  it('Check Redirect from old URL', () => {
+    cy.visit(
+      '/#/edit/eyJjb2RlIjoiZ3JhcGggVERcbiAgICBBW0NocmlzdG1hc10gLS0-fEdldCBtb25leXwgQihHbyBzaG9wcGluZylcbiAgICBCIC0tPiBDe0xldCBtZSB0aGlua31cbiAgICBDIC0tPnxPbmV8IERbTGFwdG9wXVxuICAgIEMgLS0-fFR3b3wgRVtpUGhvbmVdXG4gICAgQyAtLT58VGhyZWV8IEZbZmE6ZmEtY2FyIENhcl0iLCJtZXJtYWlkIjp7InRoZW1lIjoiZGVmYXVsdCJ9LCJ1cGRhdGVFZGl0b3IiOmZhbHNlfQ'
+    );
+    cy.url().should('include', '/edit#pako:eNp');
+  });
+
+  it('should load sample diagrams when clicked', () => {
+    cy.contains('Sample Diagrams').click();
+    cy.contains('Pie').click();
+    cy.contains('pie title Pets adopted by volunteers');
+    cy.contains('Class').click();
+    cy.contains('classDiagram');
+  });
+
+  (Cypress.env('CI') === 'true' ? describe : describe.skip)('github', () => {
+    it('should load diagram from gist', () => {
+      cy.visit(`/edit?gist=https://gist.github.com/sidharthv96/6268a23e673a533dcb198f241fd7012a`);
+      cy.contains('History').click();
+      cy.contains('Go shopping!!');
+      cy.contains('Revisions');
+      cy.contains('sidharthv96 v8f8f1e2');
+      cy.contains('sidharthv96 v7851e19');
+      cy.getLocalStorage('codeStore').snapshot();
+    });
+
+    it('should load diagram from gist revision', () => {
+      cy.visit(
+        '/edit?gist=https://gist.github.com/sidharthv96/6268a23e673a533dcb198f241fd7012a/ec9b4ab0e41e4ff6287326cd3cb47affd7851e19'
+      );
+      cy.contains('History').click();
+      cy.contains('Party');
+      cy.contains('Revisions');
+      cy.contains('sidharthv96 v7851e19');
+      cy.getLocalStorage('codeStore').snapshot();
+    });
+
+    it('should load diagram from raw files', () => {
+      cy.visit(
+        '/edit?code=https://gist.githubusercontent.com/sidharthv96/6268a23e673a533dcb198f241fd7012a/raw/4eb03887e6a41397e80bdcdbf94017c498f8f1e2/code.mmd&config=https://gist.githubusercontent.com/sidharthv96/6268a23e673a533dcb198f241fd7012a/raw/4eb03887e6a41397e80bdcdbf94017c498f8f1e2/config.json'
+      );
+      cy.contains('Party');
+      cy.getLocalStorage('codeStore').snapshot();
+    });
+  });
+
+  // Disabled temporarily. Should be enabled after the issue is fixed in Mermaid.
+  // it('should prevent setting the "securityLevel" option via URL', () => {
+  // 	const b64State = toBase64(
+  // 		`{"code":"graph TD\\nA[\\"<img src='https://via.placeholder.com/64' width=64 />\\"]","mermaid":"{\\"securityLevel\\": \\"loose\\", \\"theme\\": \\"forest\\"}","autoSync":true,"updateDiagram":true}`,
+  // 		true
+  // 	);
+  // 	cy.on('window:confirm', () => true);
+  // 	cy.visit(`/edit#${b64State}`);
+  // 	cy.contains('Config').click();
+  // 	cy.contains('forest');
+  // 	cy.contains('securityLevel').should('not.exist');
+  // 	cy.get('#view').find('img').should('not.exist');
+  // 	cy.get('#view').contains('<img');
+  // 	cy.get('#view').contains(`src='https://via.placeholder.com/64'`);
+  // });
+
+  it.skip('should allow persisting "securityLevel" using confirm dialogue', () => {
+    const b64State = toBase64(
+      `{"code":"graph TD\\nA[\\"<img src='https://dummyimage.com/64' width=64/>\\"]","mermaid":"{\\"securityLevel\\": \\"loose\\", \\"theme\\": \\"forest\\"}","autoSync":true,"updateDiagram":true}`,
+      true
+    );
+    cy.on('window:confirm', () => false);
+    cy.visit(`/edit#${b64State}`);
+    cy.get('#editor').type(' ');
+    cy.contains('Config').click();
+    cy.contains('forest');
+    cy.contains('securityLevel');
+    cy.get('#view').find('img').should('be.visible');
+  });
+
+  it('should show troubleshooting steps if loading fails', () => {
+    cy.visit('/#/edit/eyJjb2RlIjoiZ3JhcGggVERcbiAg');
+    cy.reload(true);
+    cy.contains('Please Click here to Raise an issue in github.');
+  });
+
+  it('should load uncompressed URL', () => {
+    cy.visit(
+      '/edit/#eyJjb2RlIjoiZ3JhcGggVERcbiAgICBBW05ldyBZZWFyXSAtLT58R2V0IG1vbmV5fCBCKEdvIHNob3BwaW5nKVxuICAgIEIgLS0-IEN7TGV0IG1lIHRoaW5rfVxuICAgIEMgLS0-fE9uZXwgRFtMYXB0b3BdXG4gICAgQyAtLT58VHdvfCBFW2lQaG9uZV1cbiAgICBDIC0tPnxUaHJlZXwgRltmYTpmYS1jYXIgQ2FyXSIsIm1lcm1haWQiOiJ7XG4gIFwidGhlbWVcIjogXCJkZWZhdWx0XCJcbn0iLCJ1cGRhdGVFZGl0b3IiOmZhbHNlLCJhdXRvU3luYyI6dHJ1ZSwidXBkYXRlRGlhZ3JhbSI6ZmFsc2V9'
+    );
+    cy.contains('New Year');
+    cy.visit(
+      '/edit#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'
+    );
+    cy.contains('Animal');
+    cy.visit(
+      '/edit/#base64:eyJjb2RlIjoiZ3JhcGggVERcbiAgICBBW05ldyBZZWFyXSAtLT58R2V0IG1vbmV5fCBCKEdvIHNob3BwaW5nKVxuICAgIEIgLS0-IEN7TGV0IG1lIHRoaW5rfVxuICAgIEMgLS0-fE9uZXwgRFtMYXB0b3BdXG4gICAgQyAtLT58VHdvfCBFW2lQaG9uZV1cbiAgICBDIC0tPnxUaHJlZXwgRltmYTpmYS1jYXIgQ2FyXSIsIm1lcm1haWQiOiJ7XG4gIFwidGhlbWVcIjogXCJkZWZhdWx0XCJcbn0iLCJ1cGRhdGVFZGl0b3IiOmZhbHNlLCJhdXRvU3luYyI6dHJ1ZSwidXBkYXRlRGlhZ3JhbSI6ZmFsc2V9'
+    );
+    cy.contains('New Year');
+  });
+
+  it('should load compressed URL', () => {
+    cy.visit(
+      '/edit#pako:eNpVkM2KwkAQhF-l6dMK5gVyEDRxvYi7sF6WjIcm0zqDzg_jBJEk725Hd2G3Tw31VVFUj23QjCWeEkUD-1p5kFs2O77BN1M6QFEshg1ncMHzfYDV2ybA1YQYrT_NXvhqgqDqtxPGkI315_ElVU__h-cB6mZLMYd4-Kvsb2GAdWM_jcT_V0xicb03RyqPVLSUoJI-OEfHyZHV0rqfDAqzYccKS3k1pbNC5Ufhuqgp81rbHBJKxuXKc6Quh6-7b7HMqeNfqLYkC7gfanwAlW1ZvQ'
+    );
+    cy.contains('New Year');
+    cy.visit(
+      '/edit#pako:eNptkU1PwzAMhv9K5BOI9Q9EXBDbJA477YYqITcxndV8QD40weh_Jy1rGR0-OY_tV2_sEyivCSQogzGuGduAtnaixINji0bcf1WVWGfVXdMtx8M1faYm4B8sxR27JLClJd6nwK4VLTlN4bI4jMQd2pLe3C4KFhNNcLQ92jv9ADGLNoTdozc-zIV4ZDsNlud7RtVN7_5Sb_jYrFcN3iN_0pPbEqUZK3QbTP_Ojyv4NdR4bwTHlyMbPcOQ3WJ2CliBpWCRdbnLqFJDOpClGmRJNYauhtr1pS-_6bKMjebkA8hXNJFWgDn5_YdTIFPINDWdb3vu6r8BaWOZRQ'
+    );
+    cy.contains('Animal');
+  });
+});

cypress/e2e/themes.spec.ts

@@ -0,0 +1,56 @@
+describe('Test themes', () => {
+  describe('Test light themes', () => {
+    beforeEach(() => {
+      cy.clearLocalStorage();
+      cy.visit('/edit', {
+        onBeforeLoad(win) {
+          cy.stub(win, 'matchMedia')
+            .callThrough()
+            .withArgs('(prefers-color-scheme: dark)')
+            .returns({
+              matches: false
+            });
+        }
+      });
+      cy.contains('Change Theme').click();
+    });
+
+    it('should set light theme as default', () => {
+      cy.contains('light').parent().should('have.class', 'bordered');
+      cy.contains('dark').parent().should('not.have.class', 'bordered');
+      cy.getLocalStorage('themeStore').snapshot();
+    });
+
+    it('should change themes when clicked', () => {
+      cy.contains('light').parent().should('have.class', 'bordered');
+      cy.contains('cupcake').click();
+      cy.contains('cupcake').parent().should('have.class', 'bordered');
+      cy.contains('light').parent().should('not.have.class', 'bordered');
+      cy.contains('dark').parent().should('not.have.class', 'bordered');
+      cy.getLocalStorage('themeStore').snapshot();
+    });
+  });
+
+  describe('Test dark mode', () => {
+    beforeEach(() => {
+      cy.clearLocalStorage();
+      cy.visit('/edit', {
+        onBeforeLoad(win) {
+          cy.stub(win, 'matchMedia')
+            .callThrough()
+            .withArgs('(prefers-color-scheme: dark)')
+            .returns({
+              matches: true
+            });
+        }
+      });
+      cy.contains('Change Theme').click();
+    });
+
+    it('should set dark theme as default', () => {
+      cy.contains('light').parent().should('not.have.class', 'bordered');
+      cy.contains('dark').parent().should('have.class', 'bordered');
+      cy.getLocalStorage('themeStore').snapshot();
+    });
+  });
+});

cypress/e2e/util.ts

@@ -0,0 +1,41 @@
+export const cmd = `{${Cypress.platform === 'darwin' ? 'meta' : 'ctrl'}}`;
+
+export const getEditor = ({ bottom = true, newline = false } = {}) =>
+  cy
+    .get('#editor textarea:first')
+    .click()
+    .focused()
+    .type(`${bottom ? '{pageDown}' : cmd}`)
+    .type(`${newline ? '{enter}' : cmd}`);
+
+const downloadsFolder = Cypress.config('downloadsFolder');
+
+export const verifyFileSize = (
+  fileType: 'history' | 'diagram',
+  extension: string,
+  size: number
+) => {
+  const fileName = `mermaid-${fileType}-2022-01-01-000000.${extension}`;
+  const filePath = `${downloadsFolder}/${fileName}`;
+  cy.verifyDownload(fileName);
+  cy.readFile(filePath, null, {
+    log: false
+  }).then((buffer) => expect((buffer as ArrayBuffer).byteLength).to.be.gt(size));
+  cy.task('deleteFile', filePath);
+};
+
+export const verifyFileSnapshot = (
+  fileType: 'history' | 'diagram',
+  extension: string,
+  content: string
+) => {
+  const fileName = `mermaid-${fileType}-2022-01-01-000000.${extension}`;
+  const filePath = `${downloadsFolder}/${fileName}`;
+  cy.verifyDownload(fileName);
+  cy.readFile(filePath, null, {
+    log: false
+  }).then((buffer) =>
+    expect(new TextDecoder('utf-8').decode(buffer as ArrayBuffer)).to.contain(content)
+  );
+  cy.task('deleteFile', filePath);
+};

cypress/fixtures/example.json

@@ -1,5 +1,5 @@
 {
-	"name": "Using fixtures to represent data",
-	"email": "hello@cypress.io",
-	"body": "Fixtures are a great way to mock data for responses to routes"
+  "name": "Using fixtures to represent data",
+  "email": "hello@cypress.io",
+  "body": "Fixtures are a great way to mock data for responses to routes"
 }

cypress/integration/actions.spec.ts

@@ -1,24 +0,0 @@
-describe('Check actions', () => {
-	beforeEach(() => {
-		cy.clearLocalStorage();
-		cy.visit('/edit');
-	});
-	it('should update markdown code', () => {
-		cy.get('#markdown')
-			.invoke('val')
-			.then((oldText) => {
-				cy.get('#editor').click('bottom').type('{enter}C --> HistoryTest');
-				cy.get('#markdown')
-					.invoke('val')
-					.then((newText) => {
-						expect(oldText).to.not.eq(newText);
-					});
-			});
-	});
-
-	it('should load gists from URL', () => {
-		cy.get('#gist').type('https://gist.github.com/sidharthv96/6268a23e673a533dcb198f241fd7012a');
-		cy.contains('Load Gist').click();
-		cy.contains('Go shopping!!');
-	});
-});

cypress/integration/diagramUpdate.spec.ts

@@ -1,43 +0,0 @@
-describe('Auto sync tests', () => {
-	beforeEach(() => {
-		cy.clearLocalStorage();
-		cy.visit('/');
-	});
-	it('should dim diagram when code is edited', () => {
-		cy.contains('Auto sync').click();
-		cy.get('#view').should('not.have.class', 'outOfSync');
-		cy.get('#editor').type('  C --> Test');
-		cy.get('#view').should('have.class', 'outOfSync');
-		cy.getLocalStorage('codeStore').snapshot();
-	});
-
-	it('should show/hide sync button with auto sync', () => {
-		cy.get('[data-cy=sync]').should('not.exist');
-		cy.contains('Auto sync').click();
-		cy.get('[data-cy=sync]').should('exist');
-		cy.get('#autoSync').check();
-		cy.get('[data-cy=sync]').should('not.exist');
-	});
-	it('should not dim diagram when code is in sync', () => {
-		cy.contains('Auto sync').click();
-		cy.get('#view').should('not.have.class', 'outOfSync');
-		cy.get('#editor').type('  C --> Test');
-		cy.get('#view').should('have.class', 'outOfSync');
-		cy.get('[data-cy=sync]').click();
-		cy.get('#view').should('not.have.class', 'outOfSync');
-		cy.get('#autoSync').check();
-		cy.get('#editor').type('ing');
-		cy.get('#view').should('not.have.class', 'outOfSync');
-		cy.getLocalStorage('codeStore').snapshot();
-	});
-
-	it('supports commenting code out/in', () => {
-		const cmd = Cypress.platform === 'darwin' ? 'meta' : 'ctrl';
-
-		cy.get('#editor').type(`{uparrow}{${cmd}}/`);
-		cy.get('#view').contains('Car').should('not.exist');
-
-		cy.get('#editor').type(`{uparrow}{${cmd}}/`);
-		cy.get('#view').contains('Car').should('exist');
-	});
-});

cypress/integration/history.spec.ts

@@ -1,65 +0,0 @@
-describe('Save History', () => {
-	beforeEach(() => {
-		cy.clock();
-		cy.clearLocalStorage();
-		cy.visit('/edit');
-		cy.contains('Actions').click();
-		cy.contains('History').click();
-	});
-
-	it('should save when clicked', () => {
-		cy.get('#historyList').find('li').should('have.length', 0);
-		cy.get('#historyList').contains('No items in History');
-		cy.get('#saveHistory').click();
-		cy.get('#historyList').find('No items in History').should('not.exist');
-		cy.get('#historyList').find('li').should('have.length', 1);
-		cy.get('#saveHistory').click();
-		cy.on('window:alert', (str) => {
-			expect(str).to.equal('State already saved.');
-		});
-		cy.on('window:confirm', () => true);
-		cy.get('#editor').type('  C --> HistoryTest');
-		cy.get('#saveHistory').click();
-		cy.get('#historyList').find('li').should('have.length', 2);
-	});
-
-	it('should be able to restore and delete', () => {
-		cy.get('#saveHistory').click();
-		cy.get('#editor').type('  C --> HistoryTest');
-		cy.get('#historyList').find('No items in History').should('not.exist');
-		cy.get('#historyList').find('li').should('have.length', 1);
-		cy.contains('HistoryTest');
-		cy.contains('Restore').click();
-		cy.contains('HistoryTest').should('not.exist');
-		cy.contains('Delete').click();
-		cy.get('#historyList').find('li').should('have.length', 0);
-		cy.get('#historyList').contains('No items in History');
-		cy.get('#saveHistory').click();
-		cy.get('#editor').type('  C --> HistoryTest');
-		cy.get('#saveHistory').click();
-		cy.get('#editor').type('ing');
-		cy.get('#clearHistory').click();
-		cy.on('window:alert', (str) => {
-			expect(str).to.equal('Clear all saved items?');
-		});
-		cy.on('window:confirm', () => true);
-		cy.get('#historyList').contains('No items in History');
-	});
-
-	// TODO: Fix #639
-	// eslint-disable-next-line mocha/no-skipped-tests
-	xit('should auto save history', () => {
-		cy.get('#editor').type('  C --> HistoryTest');
-		cy.tick(70000);
-		cy.contains('Timeline').click();
-		cy.get('#historyList').find('li').should('have.length', 1);
-		cy.get('#editor').type('ing');
-		cy.tick(70000);
-		cy.get('#historyList').find('li').should('have.length', 2);
-		for (let i = 0; i < 31; i++) {
-			cy.get('#editor').type('.');
-			cy.tick(70000);
-		}
-		cy.get('#historyList').find('li').should('have.length', 30);
-	});
-});

cypress/integration/loadSite.spec.ts

@@ -1,123 +0,0 @@
-import { toBase64 } from 'js-base64';
-
-describe('Site Loads', () => {
-	beforeEach(() => {
-		cy.clearLocalStorage();
-	});
-	it('Check Home page load', () => {
-		cy.visit('/');
-		cy.url().should('include', '/edit');
-		cy.contains('History').click();
-		cy.getLocalStorage('codeStore').snapshot();
-	});
-
-	it('Check Redirect from old URL', () => {
-		cy.visit(
-			'/#/edit/eyJjb2RlIjoiZ3JhcGggVERcbiAgICBBW0NocmlzdG1hc10gLS0-fEdldCBtb25leXwgQihHbyBzaG9wcGluZylcbiAgICBCIC0tPiBDe0xldCBtZSB0aGlua31cbiAgICBDIC0tPnxPbmV8IERbTGFwdG9wXVxuICAgIEMgLS0-fFR3b3wgRVtpUGhvbmVdXG4gICAgQyAtLT58VGhyZWV8IEZbZmE6ZmEtY2FyIENhcl0iLCJtZXJtYWlkIjp7InRoZW1lIjoiZGVmYXVsdCJ9LCJ1cGRhdGVFZGl0b3IiOmZhbHNlfQ'
-		);
-		cy.url().should(
-			'include',
-			'/edit#eyJjb2RlIjoiZ3JhcGggVERcbiAgICBBW0NocmlzdG1hc10gLS0-fEdldCBtb25leXwgQihHbyBzaG9wcGluZylcbiAgICBCIC0tPiBDe0xldCBtZSB0aGlua31cbiAgICBDIC0tPnxPbmV8IERbTGFwdG9wXVxuICAgIEMgLS0-fFR3b3wgRVtpUGhvbmVdXG4gICAgQyAtLT58VGhyZWV8IEZbZmE6ZmEtY2FyIENhcl0iLCJtZXJtYWlkIjp7InRoZW1lIjoiZGVmYXVsdCJ9LCJ1cGRhdGVFZGl0b3IiOmZhbHNlfQ'
-		);
-		cy.contains('History').click();
-		cy.getLocalStorage('codeStore').snapshot();
-	});
-
-	it('should load sample diagrams when clicked', () => {
-		cy.contains('Sample Diagrams').click();
-		cy.contains('Pie Chart').click();
-		cy.contains('pie title Pets adopted by volunteers');
-		cy.contains('Class Diagram').click();
-		cy.contains('classDiagram');
-	});
-
-	it('should load diagram from gist', () => {
-		cy.visit(`/edit?gist=https://gist.github.com/sidharthv96/6268a23e673a533dcb198f241fd7012a`);
-		cy.contains('History').click();
-		cy.contains('Go shopping!!');
-		cy.contains('Revisions');
-		cy.contains('sidharthv96 v8f8f1e2');
-		cy.contains('sidharthv96 v7851e19');
-		cy.getLocalStorage('codeStore').snapshot();
-	});
-
-	it('should load diagram from gist revision', () => {
-		cy.visit(
-			'/edit?gist=https://gist.github.com/sidharthv96/6268a23e673a533dcb198f241fd7012a/ec9b4ab0e41e4ff6287326cd3cb47affd7851e19'
-		);
-		cy.contains('History').click();
-		cy.contains('Party');
-		cy.contains('Revisions');
-		cy.contains('sidharthv96 v7851e19');
-		cy.getLocalStorage('codeStore').snapshot();
-	});
-
-	it('should load diagram from raw files', () => {
-		cy.visit(
-			'/edit?code=https://gist.githubusercontent.com/sidharthv96/6268a23e673a533dcb198f241fd7012a/raw/4eb03887e6a41397e80bdcdbf94017c498f8f1e2/code.mmd&config=https://gist.githubusercontent.com/sidharthv96/6268a23e673a533dcb198f241fd7012a/raw/4eb03887e6a41397e80bdcdbf94017c498f8f1e2/config.json'
-		);
-		cy.contains('Party');
-		cy.getLocalStorage('codeStore').snapshot();
-	});
-
-	// Disabled temporarily. Should be enabled after the issue is fixed in Mermaid.
-	// it('should prevent setting the "securityLevel" option via URL', () => {
-	// 	const b64State = toBase64(
-	// 		`{"code":"graph TD\\nA[\\"<img src='https://via.placeholder.com/64' width=64 />\\"]","mermaid":"{\\"securityLevel\\": \\"loose\\", \\"theme\\": \\"forest\\"}","updateEditor":true,"autoSync":true,"updateDiagram":true}`,
-	// 		true
-	// 	);
-	// 	cy.on('window:confirm', () => true);
-	// 	cy.visit(`/edit#${b64State}`);
-	// 	cy.contains('Config').click();
-	// 	cy.contains('forest');
-	// 	cy.contains('securityLevel').should('not.exist');
-	// 	cy.get('#view').find('img').should('not.exist');
-	// 	cy.get('#view').contains('<img');
-	// 	cy.get('#view').contains(`src='https://via.placeholder.com/64'`);
-	// });
-
-	it('should allow persisting "securityLevel" using confirm dialogue', () => {
-		const b64State = toBase64(
-			`{"code":"graph TD\\nA[\\"<img src='https://via.placeholder.com/64' width=64/>\\"]","mermaid":"{\\"securityLevel\\": \\"loose\\", \\"theme\\": \\"forest\\"}","updateEditor":true,"autoSync":true,"updateDiagram":true}`,
-			true
-		);
-		cy.on('window:confirm', () => false);
-		cy.visit(`/edit#${b64State}`);
-		cy.contains('Config').click();
-		cy.contains('forest');
-		cy.contains('securityLevel');
-		cy.get('#view').find('img').should('be.visible');
-	});
-
-	it('should show troubleshooting steps if loading fails', () => {
-		cy.visit('/#/edit/eyJjb2RlIjoiZ3JhcGggVERcbiAg');
-		cy.contains('Please Click here to Raise an issue in github.');
-	});
-
-	it('should load uncompressed URL', () => {
-		cy.visit(
-			'/edit/#eyJjb2RlIjoiZ3JhcGggVERcbiAgICBBW05ldyBZZWFyXSAtLT58R2V0IG1vbmV5fCBCKEdvIHNob3BwaW5nKVxuICAgIEIgLS0-IEN7TGV0IG1lIHRoaW5rfVxuICAgIEMgLS0-fE9uZXwgRFtMYXB0b3BdXG4gICAgQyAtLT58VHdvfCBFW2lQaG9uZV1cbiAgICBDIC0tPnxUaHJlZXwgRltmYTpmYS1jYXIgQ2FyXSIsIm1lcm1haWQiOiJ7XG4gIFwidGhlbWVcIjogXCJkZWZhdWx0XCJcbn0iLCJ1cGRhdGVFZGl0b3IiOmZhbHNlLCJhdXRvU3luYyI6dHJ1ZSwidXBkYXRlRGlhZ3JhbSI6ZmFsc2V9'
-		);
-		cy.contains('New Year');
-		cy.visit(
-			'/edit#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'
-		);
-		cy.contains('Animal');
-		cy.visit(
-			'/edit/#base64:eyJjb2RlIjoiZ3JhcGggVERcbiAgICBBW05ldyBZZWFyXSAtLT58R2V0IG1vbmV5fCBCKEdvIHNob3BwaW5nKVxuICAgIEIgLS0-IEN7TGV0IG1lIHRoaW5rfVxuICAgIEMgLS0-fE9uZXwgRFtMYXB0b3BdXG4gICAgQyAtLT58VHdvfCBFW2lQaG9uZV1cbiAgICBDIC0tPnxUaHJlZXwgRltmYTpmYS1jYXIgQ2FyXSIsIm1lcm1haWQiOiJ7XG4gIFwidGhlbWVcIjogXCJkZWZhdWx0XCJcbn0iLCJ1cGRhdGVFZGl0b3IiOmZhbHNlLCJhdXRvU3luYyI6dHJ1ZSwidXBkYXRlRGlhZ3JhbSI6ZmFsc2V9'
-		);
-		cy.contains('New Year');
-	});
-
-	it('should load compressed URL', () => {
-		cy.visit(
-			'/edit#pako:eNpVkM2KwkAQhF-l6dMK5gVyEDRxvYi7sF6WjIcm0zqDzg_jBJEk725Hd2G3Tw31VVFUj23QjCWeEkUD-1p5kFs2O77BN1M6QFEshg1ncMHzfYDV2ybA1YQYrT_NXvhqgqDqtxPGkI315_ElVU__h-cB6mZLMYd4-Kvsb2GAdWM_jcT_V0xicb03RyqPVLSUoJI-OEfHyZHV0rqfDAqzYccKS3k1pbNC5Ufhuqgp81rbHBJKxuXKc6Quh6-7b7HMqeNfqLYkC7gfanwAlW1ZvQ'
-		);
-		cy.contains('New Year');
-		cy.visit(
-			'/edit#pako:eNptkU1PwzAMhv9K5BOI9Q9EXBDbJA477YYqITcxndV8QD40weh_Jy1rGR0-OY_tV2_sEyivCSQogzGuGduAtnaixINji0bcf1WVWGfVXdMtx8M1faYm4B8sxR27JLClJd6nwK4VLTlN4bI4jMQd2pLe3C4KFhNNcLQ92jv9ADGLNoTdozc-zIV4ZDsNlud7RtVN7_5Sb_jYrFcN3iN_0pPbEqUZK3QbTP_Ojyv4NdR4bwTHlyMbPcOQ3WJ2CliBpWCRdbnLqFJDOpClGmRJNYauhtr1pS-_6bKMjebkA8hXNJFWgDn5_YdTIFPINDWdb3vu6r8BaWOZRQ'
-		);
-		cy.reload();
-		cy.contains('Animal');
-	});
-});

cypress/integration/themes.spec.ts

@@ -1,57 +0,0 @@
-describe('Test themes', () => {
-	describe('Test light themes', () => {
-		beforeEach(() => {
-			cy.clearLocalStorage();
-			cy.visit('/edit', {
-				onBeforeLoad(win) {
-					cy.stub(win, 'matchMedia')
-						.callThrough()
-						.withArgs('(prefers-color-scheme: dark)')
-						.returns({
-							matches: false
-						});
-				}
-			});
-			cy.contains('Change Theme').click();
-		});
-
-		it('should set light theme as default', () => {
-			cy.contains('light').parent().should('have.class', 'bordered');
-			cy.contains('dark').parent().should('not.have.class', 'bordered');
-			cy.getLocalStorage('themeStore').snapshot();
-		});
-
-		it('should change themes when clicked', () => {
-			cy.contains('light').parent().should('have.class', 'bordered');
-			cy.contains('cupcake').click();
-			cy.contains('cupcake').parent().should('have.class', 'bordered');
-			cy.contains('light').parent().should('not.have.class', 'bordered');
-			cy.contains('dark').parent().should('not.have.class', 'bordered');
-			cy.getLocalStorage('themeStore').snapshot();
-		});
-	});
-
-	describe('Test dark mode', () => {
-		// eslint-disable-next-line mocha/no-hooks-for-single-case
-		beforeEach(() => {
-			cy.clearLocalStorage();
-			cy.visit('/edit', {
-				onBeforeLoad(win) {
-					cy.stub(win, 'matchMedia')
-						.callThrough()
-						.withArgs('(prefers-color-scheme: dark)')
-						.returns({
-							matches: true
-						});
-				}
-			});
-			cy.contains('Change Theme').click();
-		});
-
-		it('should set dark theme as default', () => {
-			cy.contains('light').parent().should('not.have.class', 'bordered');
-			cy.contains('dark').parent().should('have.class', 'bordered');
-			cy.getLocalStorage('themeStore').snapshot();
-		});
-	});
-});

cypress/plugins/index.cjs

@@ -1,31 +0,0 @@
-/// <reference types="cypress" />
-// ***********************************************************
-// This example plugins/index.js can be used to load plugins
-//
-// You can change the location of this file or turn off loading
-// the plugins file with the 'pluginsFile' configuration option.
-//
-// You can read more here:
-// https://on.cypress.io/plugins-guide
-// ***********************************************************
-
-// This function is called when a project is opened or re-opened (e.g. due to
-// the project's config changing)
-
-/**
- * @type {Cypress.PluginConfig}
- */
-// eslint-disable-next-line no-unused-vars
-import * as fs from 'fs';
-
-module.exports = (on, config) => {
-	on('task', {
-		readFileMaybe(filename) {
-			if (fs.existsSync(filename)) {
-				return fs.readFileSync(filename, 'utf8');
-			}
-
-			return null;
-		}
-	});
-};

cypress/snapshots.js

@@ -1,28 +1,28 @@
 module.exports = {
   "Site Loads": {
     "Check Home page load": {
-      "1": "{\"code\":\"graph TD\\n    A[Christmas] -->|Get money| B(Go shopping)\\n    B --> C{Let me think}\\n    C -->|One| D[Laptop]\\n    C -->|Two| E[iPhone]\\n    C -->|Three| F[fa:fa-car Car]\\n  \",\"mermaid\":\"{\\n  \\\"theme\\\": \\\"default\\\"\\n}\",\"updateEditor\":true,\"autoSync\":true,\"updateDiagram\":true}"
+      "1": "{\"code\":\"graph TD\\n    A[Christmas] -->|Get money| B(Go shopping)\\n    B --> C{Let me think}\\n    C -->|One| D[Laptop]\\n    C -->|Two| E[iPhone]\\n    C -->|Three| F[fa:fa-car Car]\\n  \",\"mermaid\":\"{\\n  \\\"theme\\\": \\\"default\\\"\\n}\",\"autoSync\":true,\"updateDiagram\":true}"
     },
     "Check Redirect from old URL": {
-      "1": "{\"code\":\"graph TD\\n    A[Christmas] -->|Get money| B(Go shopping)\\n    B --> C{Let me think}\\n    C -->|One| D[Laptop]\\n    C -->|Two| E[iPhone]\\n    C -->|Three| F[fa:fa-car Car]\",\"mermaid\":\"{\\n  \\\"theme\\\": \\\"default\\\"\\n}\",\"updateEditor\":false,\"autoSync\":true,\"updateDiagram\":true}"
+      "1": "{\"code\":\"graph TD\\n    A[Christmas] -->|Get money| B(Go shopping)\\n    B --> C{Let me think}\\n    C -->|One| D[Laptop]\\n    C -->|Two| E[iPhone]\\n    C -->|Three| F[fa:fa-car Car]\",\"mermaid\":\"{\\n  \\\"theme\\\": \\\"default\\\"\\n}\",\"autoSync\":true,\"updateDiagram\":true}"
     },
     "should load diagram from gist": {
-      "1": "{\"code\":\"graph TD\\n    A[Party] -->|Get money| B(Go shopping!!)\\n    \",\"mermaid\":\"{\\n  \\\"theme\\\": \\\"forest\\\",\\n  \\\"test\\\": \\\"hello world\\\"\\n}\",\"updateEditor\":false,\"autoSync\":true,\"updateDiagram\":true,\"loader\":{\"type\":\"gist\",\"config\":{\"url\":\"https://gist.github.com/sidharthv96/6268a23e673a533dcb198f241fd7012a\"}}}"
+      "1": "{\"code\":\"graph TD\\n    A[Party] -->|Get money| B(Go shopping!!)\\n    \",\"mermaid\":\"{\\n  \\\"theme\\\": \\\"forest\\\",\\n  \\\"test\\\": \\\"hello world\\\"\\n}\",\"autoSync\":true,\"updateDiagram\":true,\"loader\":{\"type\":\"gist\",\"config\":{\"url\":\"https://gist.github.com/sidharthv96/6268a23e673a533dcb198f241fd7012a\"}}}"
     },
     "should load diagram from gist revision": {
-      "1": "{\"code\":\"graph TD\\n    A[Party] -->|Get money| B(Go shopping)\\n    \",\"mermaid\":\"{\\n  \\\"theme\\\": \\\"forest\\\",\\n  \\\"test\\\": \\\"hello\\\"\\n}\",\"updateEditor\":false,\"autoSync\":true,\"updateDiagram\":true,\"loader\":{\"type\":\"gist\",\"config\":{\"url\":\"https://gist.github.com/sidharthv96/6268a23e673a533dcb198f241fd7012a/ec9b4ab0e41e4ff6287326cd3cb47affd7851e19\"}}}"
+      "1": "{\"code\":\"graph TD\\n    A[Party] -->|Get money| B(Go shopping)\\n    \",\"mermaid\":\"{\\n  \\\"theme\\\": \\\"forest\\\",\\n  \\\"test\\\": \\\"hello\\\"\\n}\",\"autoSync\":true,\"updateDiagram\":true,\"loader\":{\"type\":\"gist\",\"config\":{\"url\":\"https://gist.github.com/sidharthv96/6268a23e673a533dcb198f241fd7012a/ec9b4ab0e41e4ff6287326cd3cb47affd7851e19\"}}}"
     },
     "should load diagram from raw files": {
-      "1": "{\"code\":\"graph TD\\n    A[Party] -->|Get money| B(Go shopping!!)\\n    \",\"mermaid\":\"{\\n  \\\"theme\\\": \\\"forest\\\",\\n  \\\"test\\\": \\\"hello world\\\"\\n}\",\"updateEditor\":false,\"autoSync\":true,\"updateDiagram\":true,\"loader\":{\"type\":\"files\",\"config\":{\"codeURL\":\"https://gist.githubusercontent.com/sidharthv96/6268a23e673a533dcb198f241fd7012a/raw/4eb03887e6a41397e80bdcdbf94017c498f8f1e2/code.mmd\",\"configURL\":\"https://gist.githubusercontent.com/sidharthv96/6268a23e673a533dcb198f241fd7012a/raw/4eb03887e6a41397e80bdcdbf94017c498f8f1e2/config.json\"}}}"
+      "1": "{\"code\":\"graph TD\\n    A[Party] -->|Get money| B(Go shopping!!)\\n    \",\"mermaid\":\"{\\n  \\\"theme\\\": \\\"forest\\\",\\n  \\\"test\\\": \\\"hello world\\\"\\n}\",\"autoSync\":true,\"updateDiagram\":true,\"loader\":{\"type\":\"files\",\"config\":{\"codeURL\":\"https://gist.githubusercontent.com/sidharthv96/6268a23e673a533dcb198f241fd7012a/raw/4eb03887e6a41397e80bdcdbf94017c498f8f1e2/code.mmd\",\"configURL\":\"https://gist.githubusercontent.com/sidharthv96/6268a23e673a533dcb198f241fd7012a/raw/4eb03887e6a41397e80bdcdbf94017c498f8f1e2/config.json\"}}}"
     }
   },
-  "__version": "9.3.1",
+  "__version": "10.10.0",
   "Auto sync tests": {
     "should dim diagram when code is edited": {
-      "1": "{\"code\":\"graph TD\\n    A[Christmas] -->|Get money| B(Go shopping)\\n    B --> C{Let me think}\\n    C -->|One| D[Laptop]\\n    C -->|Two| E[iPhone]\\n    C -->|Three| F[fa:fa-car Car]\\n    C --> Test\",\"mermaid\":\"{\\n  \\\"theme\\\": \\\"default\\\"\\n}\",\"updateEditor\":false,\"autoSync\":false,\"updateDiagram\":false}"
+      "1": "{\"code\":\"graph TD\\n    A[Christmas] -->|Get money| B(Go shopping)\\n    B --> C{Let me think}\\n    C -->|One| D[Laptop]\\n    C -->|Two| E[iPhone]\\n    C -->|Three| F[fa:fa-car Car]\\n    C --> Test\",\"mermaid\":\"{\\n  \\\"theme\\\": \\\"default\\\"\\n}\",\"autoSync\":false,\"updateDiagram\":false}"
     },
     "should not dim diagram when code is in sync": {
-      "1": "{\"code\":\"graph TD\\n    A[Christmas] -->|Get money| B(Go shopping)\\n    B --> C{Let me think}\\n    C -->|One| D[Laptop]\\n    C -->|Two| E[iPhone]\\n    C -->|Three| F[fa:fa-car Car]\\n    C --> Testing\",\"mermaid\":\"{\\n  \\\"theme\\\": \\\"default\\\"\\n}\",\"updateEditor\":false,\"autoSync\":true,\"updateDiagram\":false}"
+      "1": "{\"code\":\"graph TD\\n    A[Christmas] -->|Get money| B(Go shopping)\\n    B --> C{Let me think}\\n    C -->|One| D[Laptop]\\n    C -->|Two| E[iPhone]\\n    C -->|Three| F[fa:fa-car Car]\\n    C --> Testing\",\"mermaid\":\"{\\n  \\\"theme\\\": \\\"default\\\"\\n}\",\"autoSync\":true,\"updateDiagram\":false}"
     }
   },
   "Test themes": {

cypress/support/commands.ts

@@ -27,12 +27,12 @@ import { register } from '@cypress/snapshot';
 // eslint-disable-next-line @typescript-eslint/no-unsafe-call
 register();
 declare global {
-	// eslint-disable-next-line @typescript-eslint/no-namespace
-	namespace Cypress {
-		interface Chainable {
-			snapshot(): void;
-		}
-	}
+  // eslint-disable-next-line @typescript-eslint/no-namespace
+  namespace Cypress {
+    interface Chainable {
+      snapshot(): void;
+    }
+  }
 }
 
 import 'cypress-localstorage-commands';

cypress/support/e2e.js

@@ -15,13 +15,14 @@
 
 // Import commands.js using ES2015 syntax:
 import './commands';
+require('cy-verify-downloads').addCustomCommand();
 
 // Alternatively you can use CommonJS syntax:
 // require('./commands')
 
 Cypress.on('uncaught:exception', (err) => {
-	/* returning false here prevents Cypress from failing the test */
-	if (err.message.includes('ResizeObserver loop limit exceeded')) {
-		return false;
-	}
+  /* returning false here prevents Cypress from failing the test */
+  if (err.message.includes('ResizeObserver loop limit exceeded')) {
+    return false;
+  }
 });

cypress/tsconfig.json

@@ -1,7 +1,7 @@
 {
-	"compilerOptions": {
-		"allowJs": true,
-		"types": ["cypress", "cypress-localstorage-commands"]
-	},
-	"include": ["**/*.ts"]
+  "compilerOptions": {
+    "allowJs": true,
+    "types": ["cypress", "cypress-localstorage-commands", "cy-verify-downloads"]
+  },
+  "include": ["**/*.ts"]
 }

nginx.conf

@@ -0,0 +1,9 @@
+server { 
+ listen 80;
+ server_name mermaid;
+ location / {
+   root /usr/share/nginx/html;
+	 # Fallback to index.html for other paths
+   try_files $uri /index.html;
+ }
+}

package.json

@@ -1,76 +1,95 @@
 {
-	"name": "mermaid-live-editor",
-	"version": "2.0.67",
-	"scripts": {
-		"dev": "svelte-kit dev --host 0.0.0.0",
-		"build": "svelte-kit build",
-		"preview": "svelte-kit preview",
-		"lint": "prettier --check --plugin-search-dir=. . && eslint --ignore-path .gitignore .",
-		"lint:fix": "prettier --write --plugin-search-dir=. . && eslint --fix --ignore-path .gitignore .",
-		"format": "prettier --write --plugin-search-dir=. .",
-		"pre-commit": "lint-staged",
-		"postinstall": "husky install",
-		"test": "cypress run",
-		"cy": "cypress open"
-	},
-	"devDependencies": {
-		"@cypress/snapshot": "^2.1.7",
-		"@sveltejs/adapter-static": "1.0.0-next.28",
-		"@sveltejs/kit": "1.0.0-next.278",
-		"@types/mermaid": "^8.2.7",
-		"@types/pako": "^1.0.3",
-		"@typescript-eslint/eslint-plugin": "^4.33.0",
-		"@typescript-eslint/parser": "^4.33.0",
-		"autoprefixer": "^10.4.2",
-		"chai": "^4.3.6",
-		"cssnano": "^5.0.17",
-		"cypress": "9.5.0",
-		"cypress-localstorage-commands": "^1.7.0",
-		"eslint": "^7.32.0",
-		"eslint-config-prettier": "^8.4.0",
-		"eslint-plugin-cypress": "^2.12.1",
-		"eslint-plugin-es": "^4.1.0",
-		"eslint-plugin-mocha": "^10.0.3",
-		"eslint-plugin-postcss-modules": "^2.0.0",
-		"eslint-plugin-svelte3": "^3.4.1",
-		"eslint-plugin-tailwindcss": "^3.5.0",
-		"husky": "^7.0.4",
-		"lint-staged": "^12.3.4",
-		"mocha": "^9.2.1",
-		"node-html-parser": "^5.2.0",
-		"postcss": "^8.4.7",
-		"postcss-load-config": "^3.1.3",
-		"prettier": "~2.5.1",
-		"prettier-plugin-svelte": "^2.6.0",
-		"svelte": "^3.46.4",
-		"svelte-preprocess": "^4.10.4",
-		"tailwindcss": "^3.0.21",
-		"tslib": "^2.3.1",
-		"typescript": "^4.5.5"
-	},
-	"type": "module",
-	"dependencies": {
-		"@analytics/google-analytics": "^0.5.3",
-		"@macfja/svelte-persistent-store": "^1.2.0",
-		"analytics": "^0.8.0",
-		"daisyui": "2.2.2",
-		"js-base64": "^3.7.2",
-		"mermaid": "8.14.0",
-		"moment": "^2.29.1",
-		"monaco-editor": "^0.32.1",
-		"monaco-mermaid": "^1.0.3",
-		"pako": "2.0.4",
-		"random-word-slugs": "^0.1.6"
-	},
-	"lint-staged": {
-		"*.{ts,svelte,js,css,md,json}": [
-			"prettier --plugin-search-dir=. --write",
-			"eslint --ignore-path .gitignore "
-		]
-	},
-	"volta": {
-		"node": "14.16.1",
-		"yarn": "1.22.10",
-		"npm": "7.11.2"
-	}
+  "name": "mermaid-live-editor",
+  "version": "2.0.67",
+  "type": "module",
+  "license": "MIT",
+  "scripts": {
+    "dev": "vite dev",
+    "dev:force": "MERMAID_LOCAL=true yarn dev --force",
+    "dev:test": "yarn dev",
+    "build": "vite build",
+    "preview": "vite preview",
+    "lint": "prettier --check --cache --plugin-search-dir=. .;eslint --ignore-path .gitignore .",
+    "lint:fix": "prettier --write --cache --plugin-search-dir=. .;eslint --fix --ignore-path .gitignore .",
+    "format": "prettier --write --cache --plugin-search-dir=. .",
+    "pre-commit": "lint-staged",
+    "postinstall": "husky install && svelte-kit sync && (git config blame.ignoreRevsFile .git-blame-ignore-revs || true)",
+    "test:unit": "vitest",
+    "test:ui": "vitest --ui",
+    "test:coverage": "vitest run --coverage",
+    "test:browser": "cypress run",
+    "test": "test:unit && test:browser",
+    "cy": "cypress open"
+  },
+  "devDependencies": {
+    "@cypress/snapshot": "2.1.7",
+    "@sveltejs/adapter-static": "1.0.0-next.46",
+    "@sveltejs/kit": "1.0.0-next.522",
+    "@testing-library/jest-dom": "5.16.5",
+    "@testing-library/svelte": "3.2.2",
+    "@types/pako": "2.0.0",
+    "@types/uuid": "8.3.4",
+    "@typescript-eslint/eslint-plugin": "5.42.0",
+    "@typescript-eslint/parser": "5.42.0",
+    "@vitest/ui": "0.25.1",
+    "autoprefixer": "10.4.12",
+    "c8": "7.12.0",
+    "chai": "4.3.6",
+    "cssnano": "5.1.13",
+    "cy-verify-downloads": "0.1.11",
+    "cypress": "11.0.1",
+    "cypress-localstorage-commands": "2.2.1",
+    "eslint": "8.27.0",
+    "eslint-config-prettier": "8.5.0",
+    "eslint-plugin-cypress": "2.12.1",
+    "eslint-plugin-es": "4.1.0",
+    "eslint-plugin-postcss-modules": "2.0.0",
+    "eslint-plugin-svelte3": "4.0.0",
+    "eslint-plugin-tailwindcss": "3.6.2",
+    "eslint-plugin-vitest": "0.0.11",
+    "esserializer": "1.3.2",
+    "husky": "8.0.1",
+    "jsdom": "20.0.1",
+    "lint-staged": "13.0.3",
+    "node-html-parser": "6.1.1",
+    "postcss": "8.4.18",
+    "postcss-load-config": "4.0.1",
+    "prettier": "2.7.1",
+    "prettier-plugin-svelte": "2.8.0",
+    "svelte": "3.53.1",
+    "svelte-preprocess": "4.10.7",
+    "tailwindcss": "3.2.1",
+    "tslib": "2.4.0",
+    "typescript": "4.8.4",
+    "vite": "3.2.2",
+    "vitest": "0.25.1"
+  },
+  "dependencies": {
+    "@mermaid-js/mermaid-mindmap": "9.2.2",
+    "analytics": "0.8.1",
+    "analytics-plugin-plausible": "0.0.6",
+    "daisyui": "2.39.1",
+    "js-base64": "3.7.2",
+    "mermaid": "9.2.2",
+    "moment": "2.29.4",
+    "monaco-editor": "0.34.1",
+    "monaco-mermaid": "1.0.6",
+    "pako": "2.1.0",
+    "random-word-slugs": "0.1.6",
+    "svg-pan-zoom": "3.6.1",
+    "uuid": "9.0.0"
+  },
+  "lint-staged": {
+    "*.{ts,svelte,js,css,md,json}": [
+      "prettier --plugin-search-dir=. --write",
+      "eslint --ignore-path .gitignore "
+    ]
+  },
+  "volta": {
+    "node": "18.12.0",
+    "yarn": "1.22.19"
+  },
+  "engines": {
+    "node": ">=16.7"
+  }
 }

postcss.config.cjs

@@ -6,18 +6,18 @@ const mode = process.env.NODE_ENV;
 const dev = mode === 'development';
 
 module.exports = {
-	plugins: [
-		// Some plugins, like postcss-nested, need to run before Tailwind
+  plugins: [
+    // Some plugins, like postcss-nested, need to run before Tailwind
 
-		tailwindcss,
+    tailwindcss,
 
-		// But others, like autoprefixer, need to run after
+    // But others, like autoprefixer, need to run after
 
-		autoprefixer,
+    autoprefixer,
 
-		!dev &&
-			cssnano({
-				preset: 'default'
-			})
-	]
+    !dev &&
+      cssnano({
+        preset: 'default'
+      })
+  ]
 };

renovate.json

@@ -1,28 +1,24 @@
 {
-	"extends": [
-		"config:base",
-		":rebaseStalePrs",
-		"group:allNonMajor",
-		"schedule:earlyMondays",
-		":automergeMinor",
-		":automergeTesters",
-		":automergeLinters",
-		":automergeTypes",
-		":automergePatch"
-	],
-	"packageRules": [
-		{
-			"matchUpdateTypes": ["minor", "patch", "pin", "digest"],
-			"automerge": true
-		},
-		{
-			"matchDatasources": ["npm"],
-			"stabilityDays": 3
-		}
-	],
-	"dependencyDashboard": true,
-	"major": {
-		"dependencyDashboardApproval": true
-	},
-	"dependencyDashboardAutoclose": true
+  "extends": [
+    "config:base",
+    ":rebaseStalePrs",
+    "group:allNonMajor",
+    "schedule:earlyMondays",
+    ":automergeMinor",
+    ":automergeTesters",
+    ":automergeLinters",
+    ":automergeTypes",
+    ":automergePatch"
+  ],
+  "packageRules": [
+    {
+      "matchUpdateTypes": ["minor", "patch", "pin", "digest"],
+      "automerge": true
+    }
+  ],
+  "dependencyDashboard": true,
+  "major": {
+    "dependencyDashboardApproval": true
+  },
+  "dependencyDashboardAutoclose": true
 }

src/app.html

@@ -1,47 +1,57 @@
 <!DOCTYPE html>
 <html lang="en">
-	<head>
-		<meta charset="utf-8" />
-		<meta name="viewport" content="width=device-width, initial-scale=1" />
-		<title>Online FlowChart &amp; Diagrams Editor - Mermaid Live Editor</title>
-		<meta
-			name="og:image"
-			content="https://github.com/mermaid-js/mermaid/raw/develop/img/header.png" />
-		<link rel="canonical" href="https://mermaid.live" />
-		<meta
-			name="description"
-			content="Simplify documentation and avoid heavy tools. Open source Visio Alternative. Commonly used for explaining your code! Mermaid is a simple markdown-like script language for generating charts from text via javascript." />
-		<link rel="icon" type="image/png" href="favicon.png" />
-		<link rel="manifest" href="manifest.json" />
-		<link
-			rel="stylesheet"
-			href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/5.15.2/css/all.min.css" />
-		<link
-			rel="stylesheet"
-			href="https://cdnjs.cloudflare.com/ajax/libs/monaco-editor/0.32.1/min/vs/editor/editor.main.min.css"
-			crossorigin="anonymous"
-			referrerpolicy="no-referrer" />
-		<script>
-			var require = {
-				paths: { vs: 'https://cdnjs.cloudflare.com/ajax/libs/monaco-editor/0.32.1/min/vs' }
-			};
-		</script>
-		<script
-			src="https://cdnjs.cloudflare.com/ajax/libs/monaco-editor/0.32.1/min/vs/loader.min.js"
-			crossorigin="anonymous"
-			referrerpolicy="no-referrer"></script>
-		<script
-			src="https://cdnjs.cloudflare.com/ajax/libs/monaco-editor/0.32.1/min/vs/editor/editor.main.nls.min.js"
-			crossorigin="anonymous"
-			referrerpolicy="no-referrer"></script>
-		<script
-			src="https://cdnjs.cloudflare.com/ajax/libs/monaco-editor/0.32.1/min/vs/editor/editor.main.js"
-			crossorigin="anonymous"
-			referrerpolicy="no-referrer"></script>
-
-		%svelte.head%
-	</head>
-	<body>
-		<div id="svelte">%svelte.body%</div>
-	</body>
+  <head>
+    <meta charset="utf-8" />
+    <meta name="viewport" content="width=device-width, initial-scale=1" />
+    <title>Online FlowChart &amp; Diagrams Editor - Mermaid Live Editor</title>
+    <meta
+      name="og:image"
+      content="https://github.com/mermaid-js/mermaid/raw/develop/img/header.png" />
+    <link rel="canonical" href="https://mermaid.live" />
+    <meta
+      name="description"
+      content="Simplify documentation and avoid heavy tools. Open source Visio Alternative. Commonly used for explaining your code! Mermaid is a simple markdown-like script language for generating charts from text via javascript." />
+    <link rel="icon" type="image/png" href="%sveltekit.assets%/favicon.svg" />
+    <link rel="mask-icon" href="%sveltekit.assets%/favicon.svg" color="#000000" />
+    <meta name="theme-color" content="#6366F1" />
+    <link rel="manifest" href="%sveltekit.assets%/manifest.json" />
+    <link
+      rel="stylesheet"
+      href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/6.2.0/css/all.min.css"
+      integrity="sha512-xh6O/CkQoPOWDdYTDqeRdPCVd1SpvCA9XXcUnZS2FmJNp1coAFzvtCN9BmamE+4aHK8yyUHUSCcJHgXloTyT2A=="
+      crossorigin="anonymous"
+      referrerpolicy="no-referrer" />
+    <link
+      rel="stylesheet"
+      href="https://cdnjs.cloudflare.com/ajax/libs/monaco-editor/0.34.1/min/vs/editor/editor.main.min.css"
+      integrity="sha512-GzcoZD7y5zvBofYtImXPZaPVhoY7xLPt+ysmbPb/vU+quSKFkcngxaSrxuwprDZL4MALUqGFmnqCxQZqMozv1Q=="
+      crossorigin="anonymous"
+      referrerpolicy="no-referrer" />
+    <script>
+      var require = {
+        paths: {
+          vs: 'https://cdnjs.cloudflare.com/ajax/libs/monaco-editor/0.34.0/min/vs'
+        }
+      };
+    </script>
+    <script
+      src="https://cdnjs.cloudflare.com/ajax/libs/monaco-editor/0.34.1/min/vs/loader.min.js"
+      integrity="sha512-6bIYsGqvLpAiEBXPdRQeFf5cueeBECtAKJjIHer3BhBZNTV3WLcLA8Tm3pDfxUwTMIS+kAZwTUvJ1IrMdX8C5w=="
+      crossorigin="anonymous"
+      referrerpolicy="no-referrer"></script>
+    <script
+      src="https://cdnjs.cloudflare.com/ajax/libs/monaco-editor/0.34.1/min/vs/editor/editor.main.nls.min.js"
+      integrity="sha512-CCv+DKWw+yZhxf4Z+ExT6HC5G+3S45TeMTYcJyYbdrv4BpK2vyALJ4FoVR/KGWDIPu7w4tNCOC9MJQIkYPR5FA=="
+      crossorigin="anonymous"
+      referrerpolicy="no-referrer"></script>
+    <script
+      src="https://cdnjs.cloudflare.com/ajax/libs/monaco-editor/0.34.1/min/vs/editor/editor.main.js"
+      integrity="sha512-BtSZPhzoyN8kq1axY6cgOFPSgLJgFwvAZ3WxeDGxEFXeFcFuK2s7Hr+zF75npVHASUY1dxudAfIVzwmgdR89Bw=="
+      crossorigin="anonymous"
+      referrerpolicy="no-referrer"></script>
+    %sveltekit.head%
+  </head>
+  <body>
+    <div id="svelte">%sveltekit.body%</div>
+  </body>
 </html>

src/app.postcss

@@ -3,8 +3,8 @@
 @tailwind utilities;
 
 .input {
-	@apply flex-1 border-primary border-solid border-2 rounded;
+  @apply flex-1 border-primary border-solid border-2 rounded;
 }
 .action-btn {
-	@apply btn btn-primary;
+  @apply btn btn-primary;
 }

src/env.d.ts

@@ -0,0 +1,14 @@
+/// <reference types="vite/client" />
+
+interface ImportMetaEnv {
+  readonly MERMAID_RENDERER_URL: string;
+  readonly MERMAID_KROKI_RENDERER_URL: string;
+  readonly MERMAID_CDN_URL: string;
+  readonly MERMAID_BASE_URL: string;
+  readonly MERMAID_LOCAL: boolean;
+  // more env variables...
+}
+
+interface ImportMeta {
+  readonly env: ImportMetaEnv;
+}

src/global.d.ts

@@ -1 +1,15 @@
+/* eslint-disable @typescript-eslint/no-empty-interface */
+/* eslint-disable @typescript-eslint/ban-types */
+/* eslint-disable @typescript-eslint/no-unused-vars */
+
 /// <reference types="@sveltejs/kit" />
+import type { TestingLibraryMatchers } from '@testing-library/jest-dom/matchers';
+
+declare global {
+  namespace jest {
+    interface Matchers<R = void>
+      // eslint-disable-next-line @typescript-eslint/ban-ts-comment
+      // @ts-ignore
+      extends TestingLibraryMatchers<typeof expect.stringContaining, R> {}
+  }
+}

src/hooks.server.ts

@@ -0,0 +1,6 @@
+import type { Handle } from '@sveltejs/kit';
+
+export const handle: Handle = async ({ event, resolve }) => {
+  const response = await resolve(event, {});
+  return response;
+};

src/hooks.ts

@@ -1,9 +0,0 @@
-import type { Handle } from '@sveltejs/kit/types/hooks';
-
-export const handle: Handle = async ({ event, resolve }) => {
-	const response = await resolve(event, {
-		ssr: false
-	});
-
-	return response;
-};

src/lib/components/Actions.svelte

@@ -0,0 +1,260 @@
+<script lang="ts">
+  import { browser } from '$app/environment';
+  import Card from '$lib/components/Card/Card.svelte';
+  import { env } from '$lib/util/env';
+  import { pakoSerde } from '$lib/util/serde';
+  import { stateStore } from '$lib/util/state';
+  import { logEvent } from '$lib/util/stats';
+  import { toBase64 } from 'js-base64';
+  import moment from 'moment';
+  const { krokiRendererUrl, rendererUrl } = env;
+
+  type Exporter = (context: CanvasRenderingContext2D, image: HTMLImageElement) => () => void;
+
+  const getFileName = (ext: string) =>
+    `mermaid-diagram-${moment().format('YYYY-MM-DD-HHmmss')}.${ext}`;
+
+  const getBase64SVG = (svg?: HTMLElement, width?: number, height?: number): string => {
+    svg?.setAttribute('height', `${height}px`);
+    svg?.setAttribute('width', `${width}px`); // Workaround https://stackoverflow.com/questions/28690643/firefox-error-rendering-an-svg-image-to-html5-canvas-with-drawimage
+    if (!svg) {
+      svg = getSvgEl();
+    }
+    const svgString = svg.outerHTML
+      .replaceAll('<br>', '<br/>')
+      .replaceAll(/<img([^>]*)>/g, (m, g: string) => `<img ${g} />`);
+    return toBase64(svgString);
+  };
+
+  const exportImage = (event: Event, exporter: Exporter) => {
+    const canvas: HTMLCanvasElement = document.createElement('canvas');
+    const svg: HTMLElement = document.querySelector('#container svg');
+    const box: DOMRect = svg.getBoundingClientRect();
+    canvas.width = box.width;
+    canvas.height = box.height;
+    if (imagemodeselected === 'width') {
+      const ratio = box.height / box.width;
+      canvas.width = userimagesize;
+      canvas.height = userimagesize * ratio;
+    } else if (imagemodeselected === 'height') {
+      const ratio = box.width / box.height;
+      canvas.width = userimagesize * ratio;
+      canvas.height = userimagesize;
+    }
+
+    const context = canvas.getContext('2d');
+    context.fillStyle = 'white';
+    context.fillRect(0, 0, canvas.width, canvas.height);
+
+    const image = new Image();
+    image.onload = exporter(context, image);
+    image.src = `data:image/svg+xml;base64,${getBase64SVG(svg, canvas.width, canvas.height)}`;
+
+    event.stopPropagation();
+    event.preventDefault();
+  };
+
+  const getSvgEl = () => {
+    const svgEl: HTMLElement = document
+      .querySelector('#container svg')
+      .cloneNode(true) as HTMLElement;
+    svgEl.setAttribute('xmlns:xlink', 'http://www.w3.org/1999/xlink');
+    const fontAwesomeCdnUrl = Array.from(document.head.getElementsByTagName('link'))
+      .map((l) => l.href)
+      .find((h) => h && h.includes('font-awesome'));
+    if (fontAwesomeCdnUrl == null) {
+      return svgEl;
+    }
+    const styleEl = document.createElement('style');
+    styleEl.innerText = `@import url("${fontAwesomeCdnUrl}");'`;
+    svgEl.prepend(styleEl);
+    return svgEl;
+  };
+
+  const simulateDownload = (download: string, href: string): void => {
+    const a = document.createElement('a');
+    a.download = download;
+    a.href = href;
+    a.click();
+    a.remove();
+  };
+  const downloadImage: Exporter = (context, image) => {
+    return () => {
+      const { canvas } = context;
+      context.drawImage(image, 0, 0, canvas.width, canvas.height);
+      simulateDownload(
+        getFileName('png'),
+        canvas.toDataURL('image/png').replace('image/png', 'image/octet-stream')
+      );
+    };
+  };
+
+  const isClipboardAvailable = (): boolean => {
+    return Object.prototype.hasOwnProperty.call(window, 'ClipboardItem') as boolean;
+  };
+
+  const clipboardCopy: Exporter = (context, image) => {
+    return () => {
+      const { canvas } = context;
+      context.drawImage(image, 0, 0, canvas.width, canvas.height);
+      canvas.toBlob((blob) => {
+        try {
+          // @ts-ignore: https://github.com/microsoft/TypeScript-DOM-lib-generator/pull/1004/files
+          void navigator.clipboard.write([
+            /* eslint-disable no-undef */
+            // @ts-ignore: https://github.com/microsoft/TypeScript/issues/43821
+            new ClipboardItem({
+              [blob.type]: blob
+            })
+          ]);
+        } catch (error) {
+          console.error(error);
+        }
+      });
+    };
+  };
+
+  const onCopyClipboard = (event: Event) => {
+    exportImage(event, clipboardCopy);
+    logEvent('copyClipboard');
+  };
+
+  const onDownloadPNG = (event: Event) => {
+    exportImage(event, downloadImage);
+    logEvent('download', {
+      type: 'png'
+    });
+  };
+
+  const onDownloadSVG = () => {
+    simulateDownload(getFileName('svg'), `data:image/svg+xml;base64,${getBase64SVG()}`);
+    logEvent('download', {
+      type: 'svg'
+    });
+  };
+
+  const onCopyMarkdown = () => {
+    (document.getElementById('markdown') as HTMLInputElement).select();
+    document.execCommand('Copy');
+    logEvent('copyMarkdown');
+  };
+
+  let gistURL = '';
+  stateStore.subscribe(({ loader }) => {
+    if (loader?.type === 'gist') {
+      // @ts-ignore Gist will have url
+      gistURL = loader.config.url;
+    }
+  });
+
+  const loadGist = () => {
+    if (!gistURL) {
+      alert('Please enter a Gist URL first');
+    }
+    window.location.href = `${window.location.pathname}?gist=${gistURL}`;
+    logEvent('loadGist');
+  };
+
+  let iUrl: string;
+  let svgUrl: string;
+  let krokiUrl: string;
+  let mdCode: string;
+  let imagemodeselected = 'auto';
+  let userimagesize = 1080;
+
+  let isNetlify = false;
+  if (browser && ['mermaid.live', 'netlify'].some((path) => window.location.host.includes(path))) {
+    isNetlify = true;
+  }
+  stateStore.subscribe(async (state) => {
+    const { code, serialized } = await state;
+    iUrl = `${rendererUrl}/img/${serialized}?type=png`;
+    svgUrl = `${rendererUrl}/svg/${serialized}`;
+    krokiUrl = `${krokiRendererUrl}/mermaid/svg/${pakoSerde.serialize(code)}`;
+    mdCode = `[![](${iUrl})](${window.location.protocol}//${window.location.host}${window.location.pathname}#${serialized})`;
+  });
+</script>
+
+<Card title="Actions" isOpen={true}>
+  <div class="flex flex-wrap gap-2 m-2">
+    {#if isClipboardAvailable()}
+      <button class="action-btn w-full" on:click={onCopyClipboard}
+        ><i class="far fa-copy mr-2" /> Copy Image to clipboard
+      </button>
+    {/if}
+    <button id="downloadPNG" class="action-btn flex-grow" on:click={onDownloadPNG}>
+      <i class="fas fa-download mr-2" /> PNG
+    </button>
+    <button id="downloadSVG" class="action-btn flex-grow" on:click={onDownloadSVG}>
+      <i class="fas fa-download mr-2" /> SVG
+    </button>
+    <a target="_blank" rel="noreferrer" class="flex-grow" href={iUrl}>
+      <button class="action-btn w-full">
+        <i class="fas fa-external-link-alt mr-2" /> PNG
+      </button>
+    </a>
+    <a target="_blank" rel="noreferrer" class="flex-grow" href={svgUrl}>
+      <button class="action-btn w-full">
+        <i class="fas fa-external-link-alt mr-2" /> SVG
+      </button>
+    </a>
+    <a target="_blank" rel="noreferrer" class="flex-grow" href={krokiUrl}>
+      <button class="action-btn w-full">
+        <i class="fas fa-external-link-alt mr-2" /> Kroki
+      </button>
+    </a>
+
+    <div class="flex gap-2 items-center">
+      PNG size
+      <label for="autosize">
+        <input type="radio" value="auto" id="autosize" bind:group={imagemodeselected} /> Auto
+      </label>
+
+      <label for="width">
+        <input type="radio" value="width" id="width" bind:group={imagemodeselected} /> Width
+      </label>
+
+      <label for="height">
+        <input type="radio" value="height" id="height" bind:group={imagemodeselected} /> Height
+      </label>
+
+      {#if imagemodeselected !== 'auto'}
+        <input
+          id="height"
+          class="input"
+          type="number"
+          min="3"
+          max="10000"
+          bind:value={userimagesize} />
+      {/if}
+    </div>
+
+    <div class="w-full flex gap-2 items-center">
+      <input class="input" id="markdown" type="text" value={mdCode} on:click={onCopyMarkdown} />
+      <label for="markdown">
+        <button class="btn btn-primary btn-md flex-auto" on:click={onCopyMarkdown}>
+          Copy Markdown
+        </button>
+      </label>
+    </div>
+
+    <div class="w-full flex gap-2 items-center">
+      <input
+        class="input"
+        id="gist"
+        type="text"
+        bind:value={gistURL}
+        placeholder="Enter Gist URL" />
+      <label for="gist">
+        <button class="btn btn-primary btn-md flex-auto" on:click={loadGist}> Load Gist </button>
+      </label>
+    </div>
+    {#if isNetlify}
+      <div class="w-full flex items-center justify-center">
+        <a class="link underline text-gray-500 text-sm" href="https://netlify.com">
+          This site is powered by Netlify
+        </a>
+      </div>
+    {/if}
+  </div>
+</Card>

src/lib/components/Card/Card.svelte

@@ -0,0 +1,31 @@
+<script lang="ts">
+  import type { Tab } from '$lib/types';
+  import { slide } from 'svelte/transition';
+  import Tabs from './Tabs.svelte';
+  export let isCloseable = true;
+  export let isOpen = true;
+  export let tabs: Tab[] = [];
+  export let activeTabID: string = '';
+  export let title: string;
+  $: isOpen = isCloseable ? isOpen : true;
+  $: isTabsShown = isOpen && tabs.length > 0;
+</script>
+
+<div class="card rounded overflow-hidden m-2 flex-grow flex flex-col shadow-2xl">
+  <div
+    class="bg-primary p-2 {isTabsShown ? 'pb-0' : ''} flex-none cursor-pointer"
+    on:click={() => (isOpen = !isOpen)}
+    on:keypress={() => (isOpen = !isOpen)}>
+    <div class="flex justify-between">
+      <Tabs on:select {tabs} bind:isOpen {title} {isCloseable} {activeTabID} />
+      <div class="flex gap-x-4 items-center {isTabsShown ? '-mt-2' : ''}">
+        <slot name="actions" />
+      </div>
+    </div>
+  </div>
+  {#if isOpen}
+    <div class="card-body p-0 flex-grow overflow-auto text-base-content" transition:slide>
+      <slot />
+    </div>
+  {/if}
+</div>

src/lib/components/Card/Tabs.svelte

@@ -0,0 +1,52 @@
+<script lang="ts">
+  import type { Tab, TabEvents } from '$lib/types';
+  import { createEventDispatcher } from 'svelte';
+  import { fade } from 'svelte/transition';
+  export let isCloseable = true;
+  export let tabs: Tab[];
+  export let title: string;
+  export let isOpen = false;
+  export let activeTabID: string;
+
+  if (!activeTabID && tabs.length > 0) {
+    activeTabID = tabs[0].id;
+  }
+  const dispatch = createEventDispatcher<TabEvents>();
+  const toggleTabs = (tab: Tab) => {
+    activeTabID = tab.id;
+    dispatch('select', tab);
+  };
+</script>
+
+<div class="flex cursor-default">
+  <span
+    class="mr-2 font-semibold"
+    on:click|stopPropagation={() => (isOpen = !isOpen)}
+    on:keypress|stopPropagation={() => (isOpen = !isOpen)}>
+    {#if isCloseable}
+      <i class="fas fa-chevron-right icon" class:isOpen />
+    {/if}
+    {title}</span>
+  {#if isOpen && tabs}
+    <ul class="tabs" transition:fade>
+      {#each tabs as tab}
+        <div
+          class="tab tab-lifted {activeTabID === tab.id ? 'tab-active' : 'text-primary-content'}"
+          on:click|stopPropagation={() => toggleTabs(tab)}
+          on:keypress|stopPropagation={() => toggleTabs(tab)}>
+          <i class="mr-1 {tab.icon}" />
+          {tab.title}
+        </div>
+      {/each}
+    </ul>
+  {/if}
+</div>
+
+<style>
+  .icon {
+    transition-duration: 0.5s;
+  }
+  .isOpen {
+    transform: rotate(90deg);
+  }
+</style>

src/lib/components/Card/__snapshots__/card.test.ts.snap

@@ -0,0 +1,3 @@
+// Vitest Snapshot v1
+
+exports[`card.svelte > mounts 1`] = `"<div><div class=\\"card rounded overflow-hidden m-2 flex-grow flex flex-col shadow-2xl\\"><div class=\\"bg-primary p-2 pb-0 flex-none cursor-pointer\\"><div class=\\"flex justify-between\\"><div class=\\"flex cursor-default s-_wx1E_JHsCoF\\"><span class=\\"mr-2 font-semibold s-_wx1E_JHsCoF\\"><i class=\\"fas fa-chevron-right icon s-_wx1E_JHsCoF isOpen\\"></i> TabTest</span> <ul class=\\"tabs s-_wx1E_JHsCoF\\"><div class=\\"tab tab-lifted tab-active s-_wx1E_JHsCoF\\"><i class=\\"mr-1 undefined s-_wx1E_JHsCoF\\"></i> title1 </div><div class=\\"tab tab-lifted text-primary-content s-_wx1E_JHsCoF\\"><i class=\\"mr-1 undefined s-_wx1E_JHsCoF\\"></i> title2 </div></ul></div><!--<Tabs>--> <div class=\\"flex gap-x-4 items-center -mt-2\\"></div></div></div> <div class=\\"card-body p-0 flex-grow overflow-auto text-base-content\\"></div></div><!--<Card>--></div>"`;

src/lib/components/Card/card.test.ts

@@ -0,0 +1,24 @@
+import { cleanup, render } from '@testing-library/svelte';
+import { describe, expect, it, afterEach } from 'vitest';
+import Card from './Card.svelte';
+
+describe('card.svelte', () => {
+  // TODO: @testing-library/svelte claims to add this automatically but it doesn't work without explicit afterEach
+  afterEach(() => cleanup());
+
+  it('mounts', () => {
+    const { container } = render(Card, {
+      title: 'TabTest',
+      tabs: [
+        { id: 't1', title: 'title1' },
+        { id: 't2', title: 'title2' }
+      ]
+    });
+    expect(container).toBeTruthy();
+    expect(container).toHaveTextContent('TabTest');
+    expect(container).toHaveTextContent('title1');
+    expect(container).toHaveTextContent('title2');
+    expect(container).not.toHaveTextContent('title3');
+    expect(container.innerHTML).toMatchSnapshot();
+  });
+});

src/lib/components/Editor.svelte

@@ -0,0 +1,115 @@
+<script lang="ts">
+  import type { EditorMode } from '$lib/types';
+  import { stateStore, updateCode, updateConfig } from '$lib/util/state';
+  import { themeStore } from '$lib/util/theme';
+  import { errorDebug, syncDiagram } from '$lib/util/util';
+  import type monaco from 'monaco-editor';
+  import { onMount } from 'svelte';
+  import initEditor from 'monaco-mermaid';
+  import { logEvent } from '$lib/util/stats';
+
+  let divEl: HTMLDivElement = null;
+  let editor: monaco.editor.IStandaloneCodeEditor;
+  let Monaco: typeof monaco;
+  let editorOptions: monaco.editor.IStandaloneEditorConstructionOptions = {
+    minimap: {
+      enabled: false
+    },
+    theme: 'mermaid',
+    overviewRulerLanes: 0
+  };
+  let text = '';
+
+  stateStore.subscribe(({ errorMarkers, editorMode, code, mermaid }) => {
+    console.log('editor store subscription', { code, mermaid });
+    if (!editor) return;
+
+    // Update editor text if it's different
+    const newText = editorMode === 'code' ? code : mermaid;
+    if (newText !== text) {
+      console.log('updating editor text', newText);
+      editor.setValue(newText);
+      text = newText;
+    }
+
+    // Update editor mode if it's different
+    const language = editorMode === 'code' ? 'mermaid' : 'json';
+    if (editor.getModel().getLanguageId() !== language) {
+      Monaco?.editor.setModelLanguage(editor.getModel(), language);
+    }
+
+    // Display/clear errors
+    Monaco?.editor.setModelMarkers(editor.getModel(), 'mermaid', errorMarkers);
+  });
+
+  themeStore.subscribe(({ isDark }) => {
+    editor && Monaco?.editor.setTheme(isDark ? 'mermaid-dark' : 'mermaid');
+  });
+
+  const handleUpdate = (text: string, mode: EditorMode) => {
+    console.log('editor HandleUpdate', { text, mode });
+    if (mode === 'code') {
+      updateCode(text);
+    } else {
+      updateConfig(text);
+    }
+  };
+
+  const loadMonaco = async () => {
+    console.log('Loading Monaco...');
+    // errorDebug();
+    let i = 0;
+    while (i++ < 500) {
+      // @ts-ignore : This is a hack to handle a svelte-kit error when importing monaco.
+      Monaco = window.monaco;
+      if (Monaco !== undefined) {
+        return;
+      }
+      await new Promise((r) => setTimeout(r, 100));
+    }
+    alert('Loading Monaco Editor failed. Please try refreshing the page.');
+  };
+
+  onMount(async () => {
+    await loadMonaco(); // Fix https://github.com/mermaid-js/mermaid-live-editor/issues/175
+    initEditor(Monaco);
+    errorDebug(100);
+    editor = Monaco.editor.create(divEl, editorOptions);
+    editor.onDidChangeModelContent(({ isFlush, changes }) => {
+      const newText = editor.getValue();
+      console.log('editor onDidChangeModelContent', { text, newText, isFlush, changes });
+      if (text === newText || isFlush) {
+        return;
+      }
+      text = newText;
+      handleUpdate(text, $stateStore.editorMode);
+    });
+    editor.addAction({
+      id: 'mermaid-render-diagram',
+      label: 'Render Diagram',
+      keybindings: [Monaco.KeyMod.CtrlCmd | Monaco.KeyCode.Enter],
+      run: function () {
+        syncDiagram();
+        logEvent('renderDiagram', {
+          method: 'keyboadShortcut'
+        });
+      }
+    });
+    Monaco?.editor.setTheme($themeStore.isDark ? 'mermaid-dark' : 'mermaid');
+    const resizeObserver = new ResizeObserver((entries) => {
+      editor.layout({
+        height: entries[0].contentRect.height,
+        width: entries[0].contentRect.width
+      });
+    });
+
+    resizeObserver.observe(divEl.parentElement);
+    console.log(`editor mounted`);
+    return () => {
+      console.log(`editor disposed`);
+      editor.dispose();
+    };
+  });
+</script>
+
+<div bind:this={divEl} id="editor" class="overflow-hidden" />

src/lib/components/History/History.svelte

@@ -0,0 +1,192 @@
+<script lang="ts">
+  import Card from '$lib/components/Card/Card.svelte';
+  import { inputStateStore, getStateString } from '$lib/util/state';
+  import {
+    addHistoryEntry,
+    historyModeStore,
+    clearHistoryData,
+    getPreviousState,
+    historyStore,
+    loaderHistoryStore,
+    restoreHistory
+  } from './history';
+  import { notify, prompt } from '$lib/util/notify';
+  import { onMount } from 'svelte';
+  import { get } from 'svelte/store';
+  import moment from 'moment';
+  import type { HistoryType, State, Tab } from '$lib/types';
+  import { logEvent } from '$lib/util/stats';
+
+  const HISTORY_SAVE_INTERVAL = 60000;
+
+  const tabSelectHandler = (message: CustomEvent<Tab>) => {
+    historyModeStore.set(message.detail.id as HistoryType);
+  };
+  let tabs: Tab[] = [
+    {
+      id: 'manual',
+      title: 'Saved',
+      icon: 'far fa-bookmark'
+    },
+    {
+      id: 'auto',
+      title: 'Timeline',
+      icon: 'fas fa-history'
+    }
+  ];
+
+  const downloadHistory = () => {
+    const data = get(historyStore);
+    const blob = new Blob([JSON.stringify(data)], { type: 'application/json' });
+    const url = URL.createObjectURL(blob);
+    const a = document.createElement('a');
+    a.href = url;
+    a.download = `mermaid-history-${moment().format('YYYY-MM-DD-HHmmss')}.json`;
+    a.click();
+    URL.revokeObjectURL(url);
+    logEvent('history', {
+      action: 'download'
+    });
+  };
+
+  const uploadHistory = () => {
+    const input = document.createElement('input');
+    input.type = 'file';
+    input.accept = 'application/json';
+    input.addEventListener('change', ({ target }: Event) => {
+      const file = (<HTMLInputElement>target).files[0];
+      if (!file) {
+        return;
+      }
+      const reader = new FileReader();
+      reader.onload = (e) => {
+        const data = JSON.parse(e.target.result as string);
+        restoreHistory(data);
+      };
+      reader.readAsText(file);
+    });
+    input.click();
+  };
+
+  const saveHistory = (auto = false) => {
+    const currentState: string = getStateString();
+    const previousState: string = getPreviousState(auto);
+    if (previousState !== currentState) {
+      addHistoryEntry({
+        state: $inputStateStore,
+        time: Date.now(),
+        type: auto ? 'auto' : 'manual'
+      });
+    } else if (!auto) {
+      notify('State already saved.');
+    }
+  };
+
+  const clearHistory = (id?: string): void => {
+    if (!id && !prompt('Clear all saved items?')) {
+      return;
+    }
+    clearHistoryData(id);
+  };
+
+  const restoreHistoryItem = (state: State): void => {
+    inputStateStore.set({ ...state, updateDiagram: true });
+  };
+
+  const relativeTime = (time: number) => {
+    const t = new Date(time);
+    return `${new Date(t).toLocaleString()} (${moment(t).fromNow()})`;
+  };
+
+  onMount(() => {
+    historyModeStore.set('manual');
+    setInterval(() => {
+      saveHistory(true);
+    }, HISTORY_SAVE_INTERVAL);
+  });
+
+  loaderHistoryStore.subscribe((entries) => {
+    if (entries.length > 0 && tabs.length === 2) {
+      tabs = [
+        {
+          id: 'loader',
+          title: 'Revisions',
+          icon: 'fab fa-git-alt'
+        },
+        ...tabs
+      ];
+      historyModeStore.set('loader');
+    }
+  });
+
+  let isOpen = false;
+</script>
+
+<Card on:select={tabSelectHandler} bind:isOpen {tabs} title="History">
+  <div slot="actions">
+    <button
+      id="uploadHistory"
+      class="btn btn-xs btn-secondary w-12"
+      on:click|stopPropagation={() => uploadHistory()}
+      title="Upload history"><i class="fa fa-upload" /></button>
+    {#if $historyStore.length > 0}
+      <button
+        id="downloadHistory"
+        class="btn btn-xs btn-secondary w-12"
+        on:click|stopPropagation={() => downloadHistory()}
+        title="Download history"><i class="fa fa-download" /></button>
+    {/if}
+    |
+    <button
+      id="saveHistory"
+      class="btn btn-xs btn-success w-12"
+      on:click|stopPropagation={() => saveHistory()}
+      title="Save current state"><i class="far fa-save" /></button>
+    {#if $historyModeStore !== 'loader'}
+      <button
+        id="clearHistory"
+        class="btn btn-xs btn-error w-12"
+        on:click|stopPropagation={() => clearHistory()}
+        title="Delete all saved states"><i class="fas fa-trash-alt" /></button>
+    {/if}
+  </div>
+  <ul class="p-2 space-y-2 overflow-auto h-56" id="historyList">
+    {#if $historyStore.length > 0}
+      {#each $historyStore as { id, state, time, name, url, type }}
+        <li class="rounded p-2 shadow flex-col">
+          <div class="flex">
+            <div class="flex-1">
+              <div class="flex flex-col text-base-content">
+                {#if url}
+                  <a
+                    href={url}
+                    target="_blank"
+                    rel="noreferrer"
+                    title="Open revision in new tab"
+                    class="hover:underline text-blue-500">{name}</a>
+                {:else}
+                  <span>{name}</span>
+                {/if}
+                <span class="text-gray-400 text-sm">{relativeTime(time)}</span>
+              </div>
+            </div>
+            <div class="flex gap-2 content-center">
+              <button class="btn btn-success" on:click={() => restoreHistoryItem(state)}
+                ><i class="fas fa-undo mr-1" />Restore</button>
+              {#if type !== 'loader'}
+                <button class="btn btn-error" on:click={() => clearHistory(id)}
+                  ><i class="fas fa-trash-alt mr-1" />Delete</button>
+              {/if}
+            </div>
+          </div>
+        </li>
+      {/each}
+    {:else}
+      <div class="m-2">
+        No items in History<br />
+        Click the Save button to save current state and restore it later.<br />
+        Timeline will automatically be saved every minute.
+      </div>
+    {/if}
+  </ul>
+</Card>

src/lib/components/History/history.test.ts

@@ -0,0 +1,120 @@
+import type { HistoryEntry } from '$lib/types';
+import { describe, it, expect } from 'vitest';
+import {
+  addHistoryEntry,
+  injectHistoryIDs,
+  clearHistoryData,
+  historyModeStore,
+  historyStore
+} from './history';
+import { defaultState } from '$lib/util/state';
+import { get } from 'svelte/store';
+
+describe('history', () => {
+  it('should handle saving individual history entry', () => {
+    expect(window.localStorage.getItem('manualHistoryStore')).toBe('[]');
+    expect(window.localStorage.getItem('autoHistoryStore')).toBe('[]');
+
+    addHistoryEntry({
+      state: defaultState,
+      time: 12345,
+      type: 'manual'
+    });
+
+    const [manualEntry]: HistoryEntry[] = JSON.parse(
+      window.localStorage.getItem('manualHistoryStore')
+    );
+
+    expect(manualEntry.time).toBe(12345);
+    expect(manualEntry.type).toBe('manual');
+    expect(manualEntry.name).not.toBeNull();
+    expect(manualEntry.state).not.toBeNull();
+
+    addHistoryEntry({
+      state: defaultState,
+      time: 54321,
+      type: 'auto'
+    });
+
+    const [autoEntry]: HistoryEntry[] = JSON.parse(window.localStorage.getItem('autoHistoryStore'));
+
+    expect(autoEntry.time).toBe(54321);
+    expect(autoEntry.type).toBe('auto');
+    expect(autoEntry.name).not.toBeNull();
+    expect(autoEntry.state).not.toBeNull();
+
+    historyModeStore.set('manual');
+    clearHistoryData();
+    historyModeStore.set('auto');
+    clearHistoryData();
+    expect(window.localStorage.getItem('manualHistoryStore')).toBe('[]');
+    expect(window.localStorage.getItem('autoHistoryStore')).toBe('[]');
+  });
+
+  it('should clear history entries', () => {
+    addHistoryEntry({
+      state: defaultState,
+      time: 12345,
+      type: 'manual'
+    });
+    addHistoryEntry({
+      state: { ...defaultState, code: 'graph TD\\n    A[Christmas] -->|Get money| B(Go shopping)' },
+      time: 123456,
+      type: 'manual'
+    });
+
+    historyModeStore.set('manual');
+    const store: HistoryEntry[] = get(historyStore);
+    expect(store.length).toBe(2);
+    clearHistoryData(store[1].id);
+    expect(get(historyStore).length).toBe(1);
+    clearHistoryData();
+    expect(get(historyStore).length).toBe(0);
+
+    historyModeStore.set('auto');
+    addHistoryEntry({
+      state: defaultState,
+      time: 54321,
+      type: 'auto'
+    });
+    addHistoryEntry({
+      state: { ...defaultState, code: 'graph TD\\n    A[Christmas] -->|Get money| B(Go shopping)' },
+      time: 654321,
+      type: 'auto'
+    });
+    expect(get(historyStore).length).toBe(2);
+    clearHistoryData();
+    expect(get(historyStore).length).toBe(0);
+    // Test calling when history is empty
+    clearHistoryData();
+    expect(get(historyStore).length).toBe(0);
+  });
+});
+
+describe('history migration', () => {
+  it('should inject history IDs as migration', () => {
+    window.localStorage.setItem(
+      'manualHistoryStore',
+      '[{"state":{"code":"graph TD\\n    A[Halloween] -->|Get money| B(Go shopping)","mermaid":"{\\n  \\"theme\\": \\"dark\\"\\n}","autoSync":true,"updateDiagram":false},"time":0,"type":"manual","name":"hollow-art"},{"state":{"code":"graph TD\\n    A[Christmas] -->|Get money| B(Go shopping)","mermaid":"{\\n  \\"theme\\": \\"dark\\"\\n}","autoSync":true,"updateDiagram":true},"time":0,"type":"manual","name":"helpful-ocean"}]'
+    );
+    window.localStorage.setItem(
+      'autoHistoryStore',
+      '[{"state":{"code":"graph TD\\n    A[New Year] -->|Get money| B(Go shopping)","mermaid":"{\\n  \\"theme\\": \\"dark\\"\\n}","autoSync":true,"updateDiagram":false},"time":0,"type":"auto","name":"barking-dog"},{"state":{"code":"graph TD\\n    A[Christmas] -->|Get money| B(Go shopping)","mermaid":"{\\n  \\"theme\\": \\"dark\\"\\n}","autoSync":true,"updateDiagram":true},"time":0,"type":"manual","name":"needy-mosquito"}]'
+    );
+    let manualHistoryStore: HistoryEntry[] = JSON.parse(
+      window.localStorage.getItem('manualHistoryStore')
+    );
+    let autoHistoryStore: HistoryEntry[] = JSON.parse(
+      window.localStorage.getItem('autoHistoryStore')
+    );
+    expect(manualHistoryStore.every(({ id }) => id !== undefined)).toBe(false);
+    expect(autoHistoryStore.every(({ id }) => id !== undefined)).toBe(false);
+
+    injectHistoryIDs();
+
+    manualHistoryStore = JSON.parse(window.localStorage.getItem('manualHistoryStore'));
+    autoHistoryStore = JSON.parse(window.localStorage.getItem('autoHistoryStore'));
+    expect(manualHistoryStore.every(({ id }) => id !== undefined)).toBe(true);
+    expect(autoHistoryStore.every(({ id }) => id !== undefined)).toBe(true);
+  });
+});

src/lib/components/History/history.ts

@@ -0,0 +1,141 @@
+import { derived, writable, get } from 'svelte/store';
+import type { Readable, Writable } from 'svelte/store';
+import { persist, localStorage } from '$lib/util/persist';
+import { generateSlug } from 'random-word-slugs';
+import type { HistoryEntry, HistoryType, Optional } from '$lib/types';
+import { v4 as uuidV4 } from 'uuid';
+import { logEvent } from '$lib/util/stats';
+
+const MAX_AUTO_HISTORY_LENGTH = 30;
+
+export const historyModeStore: Writable<HistoryType> = persist(
+  writable('manual'),
+  localStorage(),
+  'autoHistoryMode'
+);
+
+const autoHistoryStore: Writable<HistoryEntry[]> = persist(
+  writable([]),
+  localStorage(),
+  'autoHistoryStore'
+);
+
+const manualHistoryStore: Writable<HistoryEntry[]> = persist(
+  writable([]),
+  localStorage(),
+  'manualHistoryStore'
+);
+
+export const loaderHistoryStore: Writable<HistoryEntry[]> = writable([] as HistoryEntry[]);
+
+export const historyStore: Readable<HistoryEntry[]> = derived(
+  [historyModeStore, autoHistoryStore, manualHistoryStore, loaderHistoryStore],
+  ([historyMode, autoHistories, manualHistories, loadedHistories], set) => {
+    if (historyMode === 'auto') {
+      set(autoHistories);
+    } else if (historyMode === 'manual') {
+      set(manualHistories);
+    } else if (historyMode === 'loader') {
+      set(loadedHistories);
+    } else {
+      set(autoHistories);
+    }
+  }
+);
+
+export const addHistoryEntry = (entryToAdd: Optional<HistoryEntry, 'id'>): void => {
+  const entry: HistoryEntry = {
+    ...entryToAdd,
+    id: uuidV4()
+  };
+
+  if (entry.type === 'loader') {
+    loaderHistoryStore.update((entries) => [entry, ...entries]);
+    return;
+  }
+
+  if (!entry.name) {
+    entry.name = generateSlug(2);
+  }
+
+  if (entry.type === 'auto') {
+    autoHistoryStore.update((entries) => {
+      if (entries.length >= MAX_AUTO_HISTORY_LENGTH) {
+        entries = entries.slice(0, MAX_AUTO_HISTORY_LENGTH - 1);
+      }
+      return [entry, ...entries];
+    });
+  } else if (entry.type === 'manual') {
+    manualHistoryStore.update((entries) => [entry, ...entries]);
+    logEvent('history', { action: 'save' });
+  }
+};
+
+export const clearHistoryData = (idToClear?: string): void => {
+  (get(historyModeStore) === 'auto' ? autoHistoryStore : manualHistoryStore).update((entries) => {
+    if (get(historyModeStore) !== 'loader') {
+      entries = entries.filter(({ id }) => idToClear && id != idToClear);
+      logEvent('history', { action: 'clear', type: idToClear ? 'single' : 'all' });
+    }
+    return entries;
+  });
+};
+
+export const getPreviousState = (auto: boolean): string => {
+  const entries = get(auto ? autoHistoryStore : manualHistoryStore);
+  if (entries.length > 0) {
+    return JSON.stringify(entries[0].state);
+  }
+  return '';
+};
+
+export const restoreHistory = (data: HistoryEntry[]) => {
+  const entries = data.filter(validateEntry);
+  const invalidEntryCount = data.length - entries.length;
+  if (invalidEntryCount > 0) {
+    console.error(`${invalidEntryCount} invalid history entries were removed.`);
+    console.error(data);
+  }
+  if (entries.length > 0) {
+    let entryCount = 0;
+    (entries[0].type === 'auto' ? autoHistoryStore : manualHistoryStore).update((existing) => {
+      const existingIDs = new Set(existing.map(({ id }) => id));
+      const newEntries = entries.filter(({ id }) => !existingIDs.has(id));
+      entryCount = newEntries.length;
+      const combined = [...existing, ...newEntries];
+      combined.sort((a, b) => b.time - a.time);
+      return combined;
+    });
+
+    alert(
+      `${entryCount} entries restored. ${invalidEntryCount} invalid, ${
+        entries.length - entryCount
+      } duplicates.`
+    );
+    logEvent('history', {
+      action: 'restore',
+      success: entryCount,
+      invalid: invalidEntryCount,
+      duplicates: entries.length - entryCount
+    });
+  } else {
+    alert('No valid entries found.');
+  }
+};
+
+export const injectHistoryIDs = (): void => {
+  const setIDs = (entries: HistoryEntry[]) => {
+    for (const entry of entries) {
+      if (!entry.id) {
+        entry.id = uuidV4();
+      }
+    }
+    return entries;
+  };
+  autoHistoryStore.update(setIDs);
+  manualHistoryStore.update(setIDs);
+};
+
+const validateEntry = (entry: HistoryEntry): boolean => {
+  return entry.type && entry.state && entry.time && true;
+};

src/lib/components/Navbar.svelte

@@ -0,0 +1,82 @@
+<script context="module">
+  import { version } from 'mermaid/package.json';
+  import { analytics } from '$lib/util/stats';
+  analytics?.track('version', {
+    mermaidVersion: version
+  });
+</script>
+
+<script lang="ts">
+  import Theme from './Theme.svelte';
+
+  interface Link {
+    title: string;
+    href: string;
+    icon?: string;
+  }
+  const links: Link[] = [
+    {
+      title: 'Documentation',
+      href: 'https://mermaid-js.github.io/mermaid/#/n00b-gettingStarted'
+    },
+    {
+      title: 'Tutorial',
+      href: 'https://github.com/mermaid-js/mermaid/blob/develop/docs/Tutorials.md'
+    },
+    {
+      title: 'Mermaid',
+      href: 'https://github.com/mermaid-js/mermaid'
+    },
+    {
+      title: 'CLI',
+      href: 'https://github.com/mermaid-js/mermaid-cli'
+    },
+    {
+      title: '',
+      href: 'https://github.com/mermaid-js/mermaid-live-editor',
+      icon: 'fab fa-github fa-lg'
+    }
+  ];
+</script>
+
+<div class="navbar shadow-lg bg-primary p-0">
+  <div class="flex-1 px-2 mx-2">
+    <span class="text-lg font-bold">
+      <a href="/">Mermaid<span class="text-xs font-thin">v{version}</span> Live Editor</a>
+    </span>
+  </div>
+  <label for="menu-toggle" class="pointer-cursor lg:hidden block"
+    ><svg
+      class="fill-current "
+      xmlns="http://www.w3.org/2000/svg"
+      width="20"
+      height="20"
+      viewBox="0 0 20 20"
+      ><title>Menu</title><path d="M0 3h20v2H0V3zm0 6h20v2H0V9zm0 6h20v2H0v-2z" /></svg
+    ></label>
+  <input class="hidden" type="checkbox" id="menu-toggle" />
+
+  <Theme />
+  <div class="hidden lg:flex lg:items-center lg:w-auto w-full" id="menu">
+    <ul class="lg:flex items-center justify-between text-base pt-4 lg:pt-0">
+      {#each links as { title, href, icon }}
+        <li>
+          <a class="btn btn-ghost" target="_blank" rel="noreferrer" {href}>
+            {#if icon}
+              <i class={icon} />
+            {/if}
+            {title}</a>
+        </li>
+      {/each}
+    </ul>
+  </div>
+</div>
+
+<style>
+  #menu-toggle:checked + #menu {
+    display: block;
+  }
+  .navbar {
+    z-index: 10000;
+  }
+</style>

src/lib/components/Preset.svelte

@@ -0,0 +1,144 @@
+<script lang="ts">
+  import { updateCode } from '$lib/util/state';
+  import Card from '$lib/components/Card/Card.svelte';
+  import { logEvent } from '$lib/util/stats';
+
+  const samples = {
+    Flow: `graph TD
+    A[Christmas] -->|Get money| B(Go shopping)
+    B --> C{Let me think}
+    C -->|One| D[Laptop]
+    C -->|Two| E[iPhone]
+    C -->|Three| F[fa:fa-car Car]`,
+    Sequence: `sequenceDiagram
+    Alice->>+John: Hello John, how are you?
+    Alice->>+John: John, can you hear me?
+    John-->>-Alice: Hi Alice, I can hear you!
+    John-->>-Alice: I feel great!`,
+    Class: `classDiagram
+    Animal <|-- Duck
+    Animal <|-- Fish
+    Animal <|-- Zebra
+    Animal : +int age
+    Animal : +String gender
+    Animal: +isMammal()
+    Animal: +mate()
+    class Duck{
+      +String beakColor
+      +swim()
+      +quack()
+    }
+    class Fish{
+      -int sizeInFeet
+      -canEat()
+    }
+    class Zebra{
+      +bool is_wild
+      +run()
+    }`,
+    State: `stateDiagram-v2
+    [*] --> Still
+    Still --> [*]
+    Still --> Moving
+    Moving --> Still
+    Moving --> Crash
+    Crash --> [*]`,
+    Gantt: `gantt
+    title A Gantt Diagram
+    dateFormat  YYYY-MM-DD
+    section Section
+    A task           :a1, 2014-01-01, 30d
+    Another task     :after a1  , 20d
+    section Another
+    Task in sec      :2014-01-12  , 12d
+    another task      : 24d`,
+    Pie: `pie title Pets adopted by volunteers
+    "Dogs" : 386
+    "Cats" : 85
+    "Rats" : 15`,
+    ER: `erDiagram
+    CUSTOMER }|..|{ DELIVERY-ADDRESS : has
+    CUSTOMER ||--o{ ORDER : places
+    CUSTOMER ||--o{ INVOICE : "liable for"
+    DELIVERY-ADDRESS ||--o{ ORDER : receives
+    INVOICE ||--|{ ORDER : covers
+    ORDER ||--|{ ORDER-ITEM : includes
+    PRODUCT-CATEGORY ||--|{ PRODUCT : contains
+    PRODUCT ||--o{ ORDER-ITEM : "ordered in"`,
+    'User Journey': `journey
+    title My working day
+    section Go to work
+      Make tea: 5: Me
+      Go upstairs: 3: Me
+      Do work: 1: Me, Cat
+    section Go home
+      Go downstairs: 5: Me
+      Sit down: 3: Me`,
+    Git: `gitGraph
+    commit
+    commit
+    branch develop
+    checkout develop
+    commit
+    commit
+    checkout main
+    merge develop
+    commit
+    commit`,
+    Mindmap: `mindmap
+  root((mindmap))
+    Origins
+      Long history
+      ::icon(fa fa-book)
+      Popularisation
+        British popular psychology author Tony Buzan
+    Research
+      On effectivness<br/>and features
+      On Automatic creation
+        Uses
+            Creative techniques
+            Strategic planning
+            Argument mapping
+    Tools
+      Pen and paper
+      Mermaid`
+  };
+
+  const loadSampleDiagram = (diagramType: string): void => {
+    updateCode(samples[diagramType], {
+      updateDiagram: true,
+      resetPanZoom: true
+    });
+    logEvent('loadSampleDiagram', { diagramType });
+  };
+
+  // Adding in this array will add an icon to the preset menu
+  const newDiagrams: Array<keyof typeof samples> = ['Mindmap'];
+  const diagramOrder: Array<keyof typeof samples> = [
+    'Sequence',
+    'Flow',
+    'Class',
+    'State',
+    'ER',
+    'Gantt',
+    'User Journey',
+    'Git',
+    'Pie',
+    'Mindmap'
+  ];
+</script>
+
+<Card title="Sample Diagrams" isOpen={false}>
+  <div class="flex flex-wrap p-2 gap-2">
+    {#each diagramOrder as sample}
+      <button
+        class="btn btn-sm btn-primary w-28 normal-case flex-grow"
+        on:click={() => loadSampleDiagram(sample)}>
+        {sample}
+        {#if newDiagrams.includes(sample)}
+          <span class="ml-2 fa fa-heart" />
+        {/if}
+      </button>
+    {/each}
+  </div>
+</Card>

src/lib/components/Theme.svelte

@@ -0,0 +1,64 @@
+<script>
+  import { setTheme, themeStore } from '$lib/util/theme';
+
+  const themes = [
+    '🌝 light',
+    '🌚 dark',
+    '🧁 cupcake',
+    '🐝 bumblebee',
+    '✳️ emerald',
+    '🏢 corporate',
+    '🌃 synthwave',
+    '👴 retro',
+    '🤖 cyberpunk',
+    '🌸 valentine',
+    '🎃 halloween',
+    '🌷 garden',
+    '🌲 forest',
+    '🐟 aqua',
+    '👓 lofi',
+    '🖍 pastel',
+    '🧚‍♀️ fantasy',
+    '📝 wireframe',
+    '🏴 black',
+    '💎 luxury',
+    '🧛‍♂️ dracula'
+  ];
+</script>
+
+<div class="hidden lg:block dropdown">
+  <!-- svelte-ignore a11y-no-noninteractive-tabindex -->
+  <div tabindex="0" class="btn btn-ghost ">
+    <svg
+      xmlns="http://www.w3.org/2000/svg"
+      fill="none"
+      viewBox="0 0 24 24"
+      class="inline-block w-6 h-6 stroke-current md:mr-2"
+      ><path
+        stroke-linecap="round"
+        stroke-linejoin="round"
+        stroke-width="2"
+        d="M7 21a4 4 0 01-4-4V5a2 2 0 012-2h4a2 2 0 012 2v12a4 4 0 01-4 4zm0 0h12a2 2 0 002-2v-4a2 2 0 00-2-2h-2.343M11 7.343l1.657-1.657a2 2 0 012.828 0l2.829 2.829a2 2 0 010 2.828l-8.486 8.485M7 17h.01" /></svg>
+    <span class="hidden md:inline"> Change Theme </span>
+    <svg
+      xmlns="http://www.w3.org/2000/svg"
+      viewBox="0 0 1792 1792"
+      class="inline-block w-4 h-4 ml-1 fill-current"
+      ><path
+        d="M1395 736q0 13-10 23l-466 466q-10 10-23 10t-23-10l-466-466q-10-10-10-23t10-23l50-50q10-10 23-10t23 10l393 393 393-393q10-10 23-10t23 10l50 50q10 10 10 23z" /></svg>
+  </div>
+  <div
+    class="mt-14 overflow-y-auto shadow-2xl top-px dropdown-content h-96 w-56 bg-base-200 text-base-content">
+    <!-- svelte-ignore a11y-no-noninteractive-tabindex -->
+    <ul tabindex="0" class="p-4 menu compact">
+      {#each themes as theme}
+        <li class={theme.includes($themeStore.theme) ? 'bordered' : ''}>
+          <span
+            class="btn btn-ghost justify-start"
+            on:click={() => setTheme(theme)}
+            on:keypress={() => setTheme(theme)}>{theme}</span>
+        </li>
+      {/each}
+    </ul>
+  </div>
+</div>

src/lib/components/View.svelte

@@ -0,0 +1,157 @@
+<script lang="ts">
+  import { inputStateStore, stateStore, updateCodeStore } from '$lib/util/state';
+  import { onMount } from 'svelte';
+  import panzoom from 'svg-pan-zoom';
+  import type { State, ValidatedState } from '$lib/types';
+  import { logEvent } from '$lib/util/stats';
+  import { AsyncQueue, cmdKey } from '$lib/util/util';
+  import { render as renderDiagram } from '$lib/util/mermaid';
+
+  let code = '';
+  let config = '';
+  let container: HTMLDivElement;
+  let view: HTMLDivElement;
+  let error = false;
+  let outOfSync = false;
+  let hide = false;
+  let manualUpdate = true;
+  let panZoomEnabled = $stateStore.panZoom;
+  let pzoom: SvgPanZoom.Instance;
+
+  const handlePanZoomChange = () => {
+    const pan = pzoom.getPan();
+    const zoom = pzoom.getZoom();
+    updateCodeStore({ pan, zoom });
+    logEvent('panZoom');
+  };
+
+  const handlePanZoom = (state: State) => {
+    if (!state.panZoom) {
+      return;
+    }
+    hide = true;
+    pzoom?.destroy();
+    pzoom = undefined;
+    Promise.resolve().then(() => {
+      const graphDiv = document.getElementById('graph-div');
+      pzoom = panzoom(graphDiv, {
+        onPan: handlePanZoomChange,
+        onZoom: handlePanZoomChange,
+        controlIconsEnabled: true,
+        fit: true,
+        center: true
+      });
+      const { pan, zoom } = state;
+      if (pan !== undefined && zoom !== undefined && Number.isFinite(zoom)) {
+        pzoom.zoom(zoom);
+        pzoom.pan(pan);
+      }
+      hide = false;
+    });
+  };
+
+  const handleStateChange = async (state: ValidatedState) => {
+    if (state.error !== undefined) {
+      error = true;
+      return;
+    }
+    error = false;
+    try {
+      if (container && state && (state.updateDiagram || state.autoSync)) {
+        if (!state.autoSync) {
+          $inputStateStore.updateDiagram = false;
+        }
+        outOfSync = false;
+        manualUpdate = true;
+        // Do not render if there is no change in Code/Config/PanZoom
+        if (code === state.code && config === state.mermaid && panZoomEnabled === state.panZoom) {
+          return;
+        }
+        code = state.code;
+        config = state.mermaid;
+        panZoomEnabled = state.panZoom;
+        const scroll = view.parentElement.scrollTop;
+        delete container.dataset.processed;
+        await renderDiagram(
+          Object.assign({}, JSON.parse(state.mermaid)),
+          code,
+          'graph-div',
+          (svgCode, bindFunctions) => {
+            if (svgCode.length > 0) {
+              handlePanZoom(state);
+              container.innerHTML = svgCode;
+              // console.log(container.innerHTML);
+              const graphDiv = document.getElementById('graph-div');
+              graphDiv.setAttribute('height', '100%');
+              graphDiv.style.maxWidth = '100%';
+              if (bindFunctions) {
+                bindFunctions(graphDiv);
+              }
+            }
+          }
+        );
+        view.parentElement.scrollTop = scroll;
+        error = false;
+      } else if (manualUpdate) {
+        manualUpdate = false;
+      } else if (code !== state.code || config !== state.mermaid) {
+        outOfSync = true;
+      }
+    } catch (e) {
+      console.error('view fail', e);
+      error = true;
+    }
+  };
+
+  const q = new AsyncQueue(handleStateChange);
+
+  onMount(() => {
+    stateStore.subscribe(async (state) => {
+      await q.process(state);
+    });
+    window.addEventListener('resize', () => {
+      if ($stateStore.panZoom && pzoom) {
+        pzoom.resize();
+      }
+    });
+    console.log('View mounted');
+  });
+</script>
+
+{#if (error && $stateStore.error instanceof Error) || outOfSync}
+  <div
+    class="absolute w-full p-2 z-10 {error
+      ? 'text-red-600'
+      : 'text-yellow-600'} bg-base-100 bg-opacity-80 text-center"
+    id="errorContainer">
+    {#if error}
+      {$stateStore.error}
+    {:else}
+      Diagram out of sync. <br />
+      Press <i class="fas fa-sync" /> (Sync button) or <kbd>{cmdKey} + Enter</kbd> to sync.
+    {/if}
+  </div>
+{/if}
+
+<div id="view" bind:this={view} class="p-2 h-full" class:error class:outOfSync>
+  <div id="container" bind:this={container} class="h-full overflow-auto" class:hide />
+</div>
+
+<style>
+  #view {
+    flex: 1;
+  }
+
+  #container {
+    transition: visibility 0.3s;
+  }
+
+  .error,
+  .outOfSync {
+    opacity: 0.5;
+  }
+
+  .hide {
+    visibility: hidden;
+  }
+</style>

src/lib/components/actions.svelte

@@ -1,226 +1,260 @@
 <script lang="ts">
-	import { browser } from '$app/env';
+  import { browser } from '$app/environment';
+  import Card from '$lib/components/Card/Card.svelte';
+  import { env } from '$lib/util/env';
+  import { pakoSerde } from '$lib/util/serde';
+  import { stateStore } from '$lib/util/state';
+  import { logEvent } from '$lib/util/stats';
+  import { toBase64 } from 'js-base64';
+  import moment from 'moment';
+  const { krokiRendererUrl, rendererUrl } = env;
 
-	import Card from '$lib/components/card/card.svelte';
-	import { krokiRendererUrl, rendererUrl } from '$lib/util/env';
-	import { pakoSerde } from '$lib/util/serde';
-	import { serializedState, codeStore } from '$lib/util/state';
-	import { toBase64 } from 'js-base64';
-	import moment from 'moment';
+  type Exporter = (context: CanvasRenderingContext2D, image: HTMLImageElement) => () => void;
 
-	type Exporter = (context: CanvasRenderingContext2D, image: HTMLImageElement) => () => void;
+  const getFileName = (ext: string) =>
+    `mermaid-diagram-${moment().format('YYYY-MM-DD-HHmmss')}.${ext}`;
 
-	const getBase64SVG = (svg?: HTMLElement, width?: number, height?: number): string => {
-		svg?.setAttribute('height', `${height}px`);
-		svg?.setAttribute('width', `${width}px`); // Workaround https://stackoverflow.com/questions/28690643/firefox-error-rendering-an-svg-image-to-html5-canvas-with-drawimage
-		if (!svg) {
-			svg = document.querySelector('#container svg');
-		}
-		const svgString = svg.outerHTML
-			.replaceAll('<br>', '<br/>')
-			.replaceAll(/<img([^>]*)>/g, (m, g: string) => `<img ${g} />`);
-		return toBase64(svgString);
-	};
+  const getBase64SVG = (svg?: HTMLElement, width?: number, height?: number): string => {
+    svg?.setAttribute('height', `${height}px`);
+    svg?.setAttribute('width', `${width}px`); // Workaround https://stackoverflow.com/questions/28690643/firefox-error-rendering-an-svg-image-to-html5-canvas-with-drawimage
+    if (!svg) {
+      svg = getSvgEl();
+    }
+    const svgString = svg.outerHTML
+      .replaceAll('<br>', '<br/>')
+      .replaceAll(/<img([^>]*)>/g, (m, g: string) => `<img ${g} />`);
+    return toBase64(svgString);
+  };
 
-	const exportImage = (event: Event, exporter: Exporter) => {
-		const canvas: HTMLCanvasElement = document.createElement('canvas');
-		const svg: HTMLElement = document.querySelector('#container svg');
-		const box: DOMRect = svg.getBoundingClientRect();
-		canvas.width = box.width;
-		canvas.height = box.height;
-		if (imagemodeselected === 'width') {
-			const ratio = box.height / box.width;
-			canvas.width = userimagesize;
-			canvas.height = userimagesize * ratio;
-		} else if (imagemodeselected === 'height') {
-			const ratio = box.width / box.height;
-			canvas.width = userimagesize * ratio;
-			canvas.height = userimagesize;
-		}
+  const exportImage = (event: Event, exporter: Exporter) => {
+    const canvas: HTMLCanvasElement = document.createElement('canvas');
+    const svg: HTMLElement = document.querySelector('#container svg');
+    const box: DOMRect = svg.getBoundingClientRect();
+    canvas.width = box.width;
+    canvas.height = box.height;
+    if (imagemodeselected === 'width') {
+      const ratio = box.height / box.width;
+      canvas.width = userimagesize;
+      canvas.height = userimagesize * ratio;
+    } else if (imagemodeselected === 'height') {
+      const ratio = box.width / box.height;
+      canvas.width = userimagesize * ratio;
+      canvas.height = userimagesize;
+    }
 
-		const context = canvas.getContext('2d');
-		context.fillStyle = 'white';
-		context.fillRect(0, 0, canvas.width, canvas.height);
+    const context = canvas.getContext('2d');
+    context.fillStyle = 'white';
+    context.fillRect(0, 0, canvas.width, canvas.height);
 
-		const image = new Image();
-		image.onload = exporter(context, image);
-		image.src = `data:image/svg+xml;base64,${getBase64SVG(svg, canvas.width, canvas.height)}`;
+    const image = new Image();
+    image.onload = exporter(context, image);
+    image.src = `data:image/svg+xml;base64,${getBase64SVG(svg, canvas.width, canvas.height)}`;
 
-		event.stopPropagation();
-		event.preventDefault();
-	};
+    event.stopPropagation();
+    event.preventDefault();
+  };
 
-	const simulateDownload = (download: string, href: string): void => {
-		const a = document.createElement('a');
-		a.download = download;
-		a.href = href;
-		a.click();
-		a.remove();
-	};
-	const downloadImage: Exporter = (context, image) => {
-		return () => {
-			const { canvas } = context;
-			context.drawImage(image, 0, 0, canvas.width, canvas.height);
-			simulateDownload(
-				`mermaid-diagram-${moment().format('YYYYMMDDHHmmss')}.png`,
-				canvas.toDataURL('image/png').replace('image/png', 'image/octet-stream')
-			);
-		};
-	};
+  const getSvgEl = () => {
+    const svgEl: HTMLElement = document
+      .querySelector('#container svg')
+      .cloneNode(true) as HTMLElement;
+    svgEl.setAttribute('xmlns:xlink', 'http://www.w3.org/1999/xlink');
+    const fontAwesomeCdnUrl = Array.from(document.head.getElementsByTagName('link'))
+      .map((l) => l.href)
+      .find((h) => h && h.includes('font-awesome'));
+    if (fontAwesomeCdnUrl == null) {
+      return svgEl;
+    }
+    const styleEl = document.createElement('style');
+    styleEl.innerText = `@import url("${fontAwesomeCdnUrl}");'`;
+    svgEl.prepend(styleEl);
+    return svgEl;
+  };
 
-	const isClipboardAvailable = (): boolean => {
-		return Object.prototype.hasOwnProperty.call(window, 'ClipboardItem') as boolean;
-	};
+  const simulateDownload = (download: string, href: string): void => {
+    const a = document.createElement('a');
+    a.download = download;
+    a.href = href;
+    a.click();
+    a.remove();
+  };
+  const downloadImage: Exporter = (context, image) => {
+    return () => {
+      const { canvas } = context;
+      context.drawImage(image, 0, 0, canvas.width, canvas.height);
+      simulateDownload(
+        getFileName('png'),
+        canvas.toDataURL('image/png').replace('image/png', 'image/octet-stream')
+      );
+    };
+  };
 
-	const clipboardCopy: Exporter = (context, image) => {
-		return () => {
-			const { canvas } = context;
-			context.drawImage(image, 0, 0, canvas.width, canvas.height);
-			canvas.toBlob((blob) => {
-				try {
-					// @ts-ignore: https://github.com/microsoft/TypeScript-DOM-lib-generator/pull/1004/files
-					void navigator.clipboard.write([
-						/* eslint-disable no-undef */
-						// @ts-ignore: https://github.com/microsoft/TypeScript/issues/43821
-						new ClipboardItem({
-							[blob.type]: blob
-						})
-					]);
-				} catch (error) {
-					console.error(error);
-				}
-			});
-		};
-	};
+  const isClipboardAvailable = (): boolean => {
+    return Object.prototype.hasOwnProperty.call(window, 'ClipboardItem') as boolean;
+  };
 
-	const onCopyClipboard = (event: Event) => {
-		exportImage(event, clipboardCopy);
-	};
+  const clipboardCopy: Exporter = (context, image) => {
+    return () => {
+      const { canvas } = context;
+      context.drawImage(image, 0, 0, canvas.width, canvas.height);
+      canvas.toBlob((blob) => {
+        try {
+          // @ts-ignore: https://github.com/microsoft/TypeScript-DOM-lib-generator/pull/1004/files
+          void navigator.clipboard.write([
+            /* eslint-disable no-undef */
+            // @ts-ignore: https://github.com/microsoft/TypeScript/issues/43821
+            new ClipboardItem({
+              [blob.type]: blob
+            })
+          ]);
+        } catch (error) {
+          console.error(error);
+        }
+      });
+    };
+  };
 
-	const onDownloadPNG = (event: Event) => {
-		exportImage(event, downloadImage);
-	};
+  const onCopyClipboard = (event: Event) => {
+    exportImage(event, clipboardCopy);
+    logEvent('copyClipboard');
+  };
 
-	const onDownloadSVG = () => {
-		simulateDownload(
-			`mermaid-diagram-${moment().format('YYYYMMDDHHmmss')}.svg`,
-			`data:image/svg+xml;base64,${getBase64SVG()}`
-		);
-	};
+  const onDownloadPNG = (event: Event) => {
+    exportImage(event, downloadImage);
+    logEvent('download', {
+      type: 'png'
+    });
+  };
 
-	const onCopyMarkdown = () => {
-		(document.getElementById('markdown') as HTMLInputElement).select();
-		document.execCommand('Copy');
-	};
+  const onDownloadSVG = () => {
+    simulateDownload(getFileName('svg'), `data:image/svg+xml;base64,${getBase64SVG()}`);
+    logEvent('download', {
+      type: 'svg'
+    });
+  };
 
-	let gistURL = '';
-	codeStore.subscribe((state) => {
-		if (state.loader?.type === 'gist') {
-			// @ts-ignore Gist will have url
-			gistURL = state.loader.config.url;
-		}
-	});
+  const onCopyMarkdown = () => {
+    (document.getElementById('markdown') as HTMLInputElement).select();
+    document.execCommand('Copy');
+    logEvent('copyMarkdown');
+  };
 
-	const loadGist = () => {
-		if (!gistURL) {
-			alert('Please enter a Gist URL first');
-		}
-		window.location.href = `${window.location.pathname}?gist=${gistURL}`;
-	};
+  let gistURL = '';
+  stateStore.subscribe(({ loader }) => {
+    if (loader?.type === 'gist') {
+      // @ts-ignore Gist will have url
+      gistURL = loader.config.url;
+    }
+  });
 
-	let iUrl: string;
-	let svgUrl: string;
-	let krokiUrl: string;
-	let mdCode: string;
-	let imagemodeselected = 'auto';
-	let userimagesize = 1080;
+  const loadGist = () => {
+    if (!gistURL) {
+      alert('Please enter a Gist URL first');
+    }
+    window.location.href = `${window.location.pathname}?gist=${gistURL}`;
+    logEvent('loadGist');
+  };
 
-	let isNetlify = false;
-	if (browser && ['mermaid.live', 'netlify'].some((path) => window.location.host.includes(path))) {
-		isNetlify = true;
-	}
-	serializedState.subscribe((encodedState: string) => {
-		iUrl = `${rendererUrl}/img/${encodedState}`;
-		svgUrl = `${rendererUrl}/svg/${encodedState}`;
-		krokiUrl = `${krokiRendererUrl}/mermaid/svg/${pakoSerde.serialize($codeStore.code)}`;
-		mdCode = `[![](${iUrl})](${window.location.protocol}//${window.location.host}${window.location.pathname}#${encodedState})`;
-	});
+  let iUrl: string;
+  let svgUrl: string;
+  let krokiUrl: string;
+  let mdCode: string;
+  let imagemodeselected = 'auto';
+  let userimagesize = 1080;
+
+  let isNetlify = false;
+  if (browser && ['mermaid.live', 'netlify'].some((path) => window.location.host.includes(path))) {
+    isNetlify = true;
+  }
+  stateStore.subscribe(async (state) => {
+    const { code, serialized } = await state;
+    iUrl = `${rendererUrl}/img/${serialized}?type=png`;
+    svgUrl = `${rendererUrl}/svg/${serialized}`;
+    krokiUrl = `${krokiRendererUrl}/mermaid/svg/${pakoSerde.serialize(code)}`;
+    mdCode = `[![](${iUrl})](${window.location.protocol}//${window.location.host}${window.location.pathname}#${serialized})`;
+  });
 </script>
 
 <Card title="Actions" isOpen={true}>
-	<div class="flex flex-wrap gap-2 m-2">
-		{#if isClipboardAvailable()}
-			<button class="action-btn w-full" on:click={onCopyClipboard}
-				><i class="far fa-copy mr-2" /> Copy Image to clipboard
-			</button>
-		{/if}
-		<button class="action-btn flex-auto" on:click={onDownloadPNG}>
-			<i class="fas fa-download mr-2" /> PNG
-		</button>
-		<button class="action-btn flex-auto" on:click={onDownloadSVG}>
-			<i class="fas fa-download mr-2" /> SVG
-		</button>
-		<button class="action-btn flex-auto">
-			<a target="_blank" href={iUrl}><i class="fas fa-external-link-alt mr-2" /> PNG</a>
-		</button>
-		<button class="action-btn flex-auto">
-			<a target="_blank" href={svgUrl}><i class="fas fa-external-link-alt mr-2" /> SVG</a>
-		</button>
-		<button class="action-btn flex-auto">
-			<a target="_blank" href={krokiUrl}><i class="fas fa-external-link-alt mr-2" /> Kroki</a>
-		</button>
+  <div class="flex flex-wrap gap-2 m-2">
+    {#if isClipboardAvailable()}
+      <button class="action-btn w-full" on:click={onCopyClipboard}
+        ><i class="far fa-copy mr-2" /> Copy Image to clipboard
+      </button>
+    {/if}
+    <button id="downloadPNG" class="action-btn flex-grow" on:click={onDownloadPNG}>
+      <i class="fas fa-download mr-2" /> PNG
+    </button>
+    <button id="downloadSVG" class="action-btn flex-grow" on:click={onDownloadSVG}>
+      <i class="fas fa-download mr-2" /> SVG
+    </button>
+    <a target="_blank" rel="noreferrer" class="flex-grow" href={iUrl}>
+      <button class="action-btn w-full">
+        <i class="fas fa-external-link-alt mr-2" /> PNG
+      </button>
+    </a>
+    <a target="_blank" rel="noreferrer" class="flex-grow" href={svgUrl}>
+      <button class="action-btn w-full">
+        <i class="fas fa-external-link-alt mr-2" /> SVG
+      </button>
+    </a>
+    <a target="_blank" rel="noreferrer" class="flex-grow" href={krokiUrl}>
+      <button class="action-btn w-full">
+        <i class="fas fa-external-link-alt mr-2" /> Kroki
+      </button>
+    </a>
 
-		<div class="flex gap-2 items-center">
-			PNG size
-			<label for="autosize">
-				<input type="radio" value="auto" id="autosize" bind:group={imagemodeselected} /> Auto
-			</label>
+    <div class="flex gap-2 items-center">
+      PNG size
+      <label for="autosize">
+        <input type="radio" value="auto" id="autosize" bind:group={imagemodeselected} /> Auto
+      </label>
 
-			<label for="width">
-				<input type="radio" value="width" id="width" bind:group={imagemodeselected} /> Width
-			</label>
+      <label for="width">
+        <input type="radio" value="width" id="width" bind:group={imagemodeselected} /> Width
+      </label>
 
-			<label for="height">
-				<input type="radio" value="height" id="height" bind:group={imagemodeselected} /> Height
-			</label>
+      <label for="height">
+        <input type="radio" value="height" id="height" bind:group={imagemodeselected} /> Height
+      </label>
 
-			{#if imagemodeselected !== 'auto'}
-				<input
-					id="height"
-					class="input"
-					type="number"
-					min="3"
-					max="10000"
-					bind:value={userimagesize} />
-			{/if}
-		</div>
+      {#if imagemodeselected !== 'auto'}
+        <input
+          id="height"
+          class="input"
+          type="number"
+          min="3"
+          max="10000"
+          bind:value={userimagesize} />
+      {/if}
+    </div>
 
-		<div class="w-full flex gap-2 items-center">
-			<input class="input" id="markdown" type="text" value={mdCode} on:click={onCopyMarkdown} />
-			<label for="markdown">
-				<button class="btn btn-primary btn-md flex-auto" on:click={onCopyMarkdown}>
-					Copy Markdown
-				</button>
-			</label>
-		</div>
+    <div class="w-full flex gap-2 items-center">
+      <input class="input" id="markdown" type="text" value={mdCode} on:click={onCopyMarkdown} />
+      <label for="markdown">
+        <button class="btn btn-primary btn-md flex-auto" on:click={onCopyMarkdown}>
+          Copy Markdown
+        </button>
+      </label>
+    </div>
 
-		<div class="w-full flex gap-2 items-center">
-			<input
-				class="input"
-				id="gist"
-				type="text"
-				bind:value={gistURL}
-				placeholder="Enter Gist URL" />
-			<label for="gist">
-				<button class="btn btn-primary btn-md flex-auto" on:click={loadGist}> Load Gist </button>
-			</label>
-		</div>
-		{#if isNetlify}
-			<div class="w-full flex items-center justify-center">
-				<a class="link underline text-gray-500 text-sm" href="https://netlify.com">
-					This site is powered by Netlify
-				</a>
-			</div>
-		{/if}
-	</div>
+    <div class="w-full flex gap-2 items-center">
+      <input
+        class="input"
+        id="gist"
+        type="text"
+        bind:value={gistURL}
+        placeholder="Enter Gist URL" />
+      <label for="gist">
+        <button class="btn btn-primary btn-md flex-auto" on:click={loadGist}> Load Gist </button>
+      </label>
+    </div>
+    {#if isNetlify}
+      <div class="w-full flex items-center justify-center">
+        <a class="link underline text-gray-500 text-sm" href="https://netlify.com">
+          This site is powered by Netlify
+        </a>
+      </div>
+    {/if}
+  </div>
 </Card>

src/lib/components/card/__snapshots__/card.test.ts.snap

@@ -0,0 +1,3 @@
+// Vitest Snapshot v1
+
+exports[`card.svelte > mounts 1`] = `"<div><div class=\\"card rounded overflow-hidden m-2 flex-grow flex flex-col shadow-2xl\\"><div class=\\"bg-primary p-2 pb-0 flex-none cursor-pointer\\"><div class=\\"flex justify-between\\"><div class=\\"flex cursor-default s-_wx1E_JHsCoF\\"><span class=\\"mr-2 font-semibold s-_wx1E_JHsCoF\\"><i class=\\"fas fa-chevron-right icon s-_wx1E_JHsCoF isOpen\\"></i> TabTest</span> <ul class=\\"tabs s-_wx1E_JHsCoF\\"><div class=\\"tab tab-lifted tab-active s-_wx1E_JHsCoF\\"><i class=\\"mr-1 undefined s-_wx1E_JHsCoF\\"></i> title1 </div><div class=\\"tab tab-lifted text-primary-content s-_wx1E_JHsCoF\\"><i class=\\"mr-1 undefined s-_wx1E_JHsCoF\\"></i> title2 </div></ul></div><!--<Tabs>--> <div class=\\"flex gap-x-4 items-center -mt-2\\"></div></div></div> <div class=\\"card-body p-0 flex-grow overflow-auto text-base-content\\"></div></div><!--<Card>--></div>"`;

src/lib/components/card/card.svelte

@@ -1,29 +1,31 @@
 <script lang="ts">
-	import type { Tab } from '$lib/types';
-	import { slide } from 'svelte/transition';
-	import Tabs from './tabs.svelte';
-	export let isCloseable = true;
-	export let isOpen = true;
-	export let tabs: Tab[] = [];
-	export let title: string;
-	$: isOpen = isCloseable ? isOpen : true;
-	$: isTabsShown = isOpen && tabs.length > 0;
+  import type { Tab } from '$lib/types';
+  import { slide } from 'svelte/transition';
+  import Tabs from './Tabs.svelte';
+  export let isCloseable = true;
+  export let isOpen = true;
+  export let tabs: Tab[] = [];
+  export let activeTabID: string = '';
+  export let title: string;
+  $: isOpen = isCloseable ? isOpen : true;
+  $: isTabsShown = isOpen && tabs.length > 0;
 </script>
 
 <div class="card rounded overflow-hidden m-2 flex-grow flex flex-col shadow-2xl">
-	<div
-		class="bg-primary p-2 {isTabsShown ? 'pb-0' : ''} flex-none cursor-pointer"
-		on:click={() => (isOpen = !isOpen)}>
-		<div class="flex justify-between">
-			<Tabs on:select {tabs} bind:isOpen {title} {isCloseable} />
-			<div class="flex gap-x-4 items-center {isTabsShown ? '-mt-2' : ''}">
-				<slot name="actions" />
-			</div>
-		</div>
-	</div>
-	{#if isOpen}
-		<div class="card-body p-0 flex-grow overflow-auto text-base-content" transition:slide>
-			<slot />
-		</div>
-	{/if}
+  <div
+    class="bg-primary p-2 {isTabsShown ? 'pb-0' : ''} flex-none cursor-pointer"
+    on:click={() => (isOpen = !isOpen)}
+    on:keypress={() => (isOpen = !isOpen)}>
+    <div class="flex justify-between">
+      <Tabs on:select {tabs} bind:isOpen {title} {isCloseable} {activeTabID} />
+      <div class="flex gap-x-4 items-center {isTabsShown ? '-mt-2' : ''}">
+        <slot name="actions" />
+      </div>
+    </div>
+  </div>
+  {#if isOpen}
+    <div class="card-body p-0 flex-grow overflow-auto text-base-content" transition:slide>
+      <slot />
+    </div>
+  {/if}
 </div>

src/lib/components/card/card.test.ts

@@ -0,0 +1,24 @@
+import { cleanup, render } from '@testing-library/svelte';
+import { describe, expect, it, afterEach } from 'vitest';
+import Card from './Card.svelte';
+
+describe('card.svelte', () => {
+  // TODO: @testing-library/svelte claims to add this automatically but it doesn't work without explicit afterEach
+  afterEach(() => cleanup());
+
+  it('mounts', () => {
+    const { container } = render(Card, {
+      title: 'TabTest',
+      tabs: [
+        { id: 't1', title: 'title1' },
+        { id: 't2', title: 'title2' }
+      ]
+    });
+    expect(container).toBeTruthy();
+    expect(container).toHaveTextContent('TabTest');
+    expect(container).toHaveTextContent('title1');
+    expect(container).toHaveTextContent('title2');
+    expect(container).not.toHaveTextContent('title3');
+    expect(container.innerHTML).toMatchSnapshot();
+  });
+});

src/lib/components/card/tabs.svelte

@@ -1,46 +1,52 @@
 <script lang="ts">
-	import type { Tab, TabEvents } from '$lib/types';
-	import { createEventDispatcher } from 'svelte';
-	import { fade } from 'svelte/transition';
-	export let isCloseable = true;
-	export let tabs: Tab[] = [];
-	export let title: string;
-	export let isOpen = false;
+  import type { Tab, TabEvents } from '$lib/types';
+  import { createEventDispatcher } from 'svelte';
+  import { fade } from 'svelte/transition';
+  export let isCloseable = true;
+  export let tabs: Tab[];
+  export let title: string;
+  export let isOpen = false;
+  export let activeTabID: string;
 
-	$: activeTabID = tabs[0]?.id;
-
-	const dispatch = createEventDispatcher<TabEvents>();
-	const toggleTabs = (tab: Tab) => {
-		activeTabID = tab.id;
-		dispatch('select', tab);
-	};
+  if (!activeTabID && tabs.length > 0) {
+    activeTabID = tabs[0].id;
+  }
+  const dispatch = createEventDispatcher<TabEvents>();
+  const toggleTabs = (tab: Tab) => {
+    activeTabID = tab.id;
+    dispatch('select', tab);
+  };
 </script>
 
 <div class="flex cursor-default">
-	<span class="mr-2 font-semibold" on:click|stopPropagation={() => (isOpen = !isOpen)}>
-		{#if isCloseable}
-			<i class="fas fa-chevron-right icon" class:isOpen />
-		{/if}
-		{title}</span>
-	{#if isOpen && tabs}
-		<ul class="tabs" transition:fade>
-			{#each tabs as tab}
-				<div
-					class="tab tab-lifted text-primary-content {activeTabID === tab.id ? 'tab-active' : ''}"
-					on:click|stopPropagation={() => toggleTabs(tab)}>
-					<i class="mr-1 {tab.icon}" />
-					{tab.title}
-				</div>
-			{/each}
-		</ul>
-	{/if}
+  <span
+    class="mr-2 font-semibold"
+    on:click|stopPropagation={() => (isOpen = !isOpen)}
+    on:keypress|stopPropagation={() => (isOpen = !isOpen)}>
+    {#if isCloseable}
+      <i class="fas fa-chevron-right icon" class:isOpen />
+    {/if}
+    {title}</span>
+  {#if isOpen && tabs}
+    <ul class="tabs" transition:fade>
+      {#each tabs as tab}
+        <div
+          class="tab tab-lifted {activeTabID === tab.id ? 'tab-active' : 'text-primary-content'}"
+          on:click|stopPropagation={() => toggleTabs(tab)}
+          on:keypress|stopPropagation={() => toggleTabs(tab)}>
+          <i class="mr-1 {tab.icon}" />
+          {tab.title}
+        </div>
+      {/each}
+    </ul>
+  {/if}
 </div>
 
 <style>
-	.icon {
-		transition-duration: 0.5s;
-	}
-	.isOpen {
-		transform: rotate(90deg);
-	}
+  .icon {
+    transition-duration: 0.5s;
+  }
+  .isOpen {
+    transform: rotate(90deg);
+  }
 </style>

src/lib/components/editor.svelte

@@ -1,85 +0,0 @@
-<script lang="ts">
-	import type { EditorEvents } from '$lib/types';
-	import { codeStore } from '$lib/util/state';
-	import { themeStore } from '$lib/util/theme';
-	import type monaco from 'monaco-editor';
-	import { createEventDispatcher, onMount } from 'svelte';
-	import initEditor from 'monaco-mermaid';
-
-	let divEl: HTMLDivElement = null;
-	let editor: monaco.editor.IStandaloneCodeEditor;
-	let Monaco;
-
-	export let text: string;
-	export let language: string;
-	export let editorOptions: monaco.editor.IStandaloneEditorConstructionOptions = {
-		value: text,
-		language: language,
-		minimap: {
-			enabled: false
-		},
-		theme: 'mermaid',
-		overviewRulerLanes: 0
-	};
-	export let errorMarkers: monaco.editor.IMarkerData[] = [];
-	let oldText = text;
-	$: editor && Monaco?.editor.setModelLanguage(editor.getModel(), language);
-	$: {
-		if (text !== oldText) {
-			if ($codeStore.updateEditor) {
-				editor?.setValue(text);
-			}
-			oldText = text;
-		}
-		editor && Monaco?.editor.setModelMarkers(editor.getModel(), 'test', errorMarkers);
-	}
-
-	themeStore.subscribe(({ isDark }) => {
-		editor && Monaco?.editor.setTheme(isDark ? 'mermaid-dark' : 'mermaid');
-	});
-
-	const dispatch = createEventDispatcher<EditorEvents>();
-	const loadMonaco = async () => {
-		let i = 0;
-		while (i++ < 10) {
-			try {
-				// @ts-ignore : This is a hack to handle a svelte-kit error when importing monaco.
-				Monaco = monaco;
-				return;
-			} catch {
-				await new Promise((r) => setTimeout(r, 500));
-			}
-		}
-		alert('Loading Monaco Editor failed. Please try refreshing the page.');
-	};
-	onMount(async () => {
-		try {
-			// @ts-ignore : This is a hack to handle a svelte-kit error when importing monaco.
-			Monaco = monaco;
-		} catch {
-			await loadMonaco(); // Fix https://github.com/mermaid-js/mermaid-live-editor/issues/175
-		}
-		initEditor(Monaco);
-		editor = Monaco.editor.create(divEl, editorOptions);
-		editor.onDidChangeModelContent(() => {
-			text = editor.getValue();
-			dispatch('update', {
-				text
-			});
-		});
-		Monaco?.editor.setTheme($themeStore.isDark ? 'mermaid-dark' : 'mermaid');
-		const resizeObserver = new ResizeObserver((entries) => {
-			editor.layout({
-				height: entries[0].contentRect.height,
-				width: entries[0].contentRect.width
-			});
-		});
-
-		resizeObserver.observe(divEl.parentElement);
-		return () => {
-			editor.dispose();
-		};
-	});
-</script>
-
-<div bind:this={divEl} id="editor" class="overflow-hidden" />

src/lib/components/history/history.svelte

@@ -1,142 +1,192 @@
 <script lang="ts">
-	import Card from '$lib/components/card/card.svelte';
-	import { codeStore, getStateString } from '$lib/util/state';
-	import {
-		addHistoryEntry,
-		historyModeStore,
-		clearHistoryData,
-		getPreviousState,
-		historyStore,
-		loaderHistoryStore
-	} from './history';
-	import { notify, prompt } from '$lib/util/notify';
-	import { onMount } from 'svelte';
-	import moment from 'moment';
-	import type { HistoryType, State, Tab } from '$lib/types';
+  import Card from '$lib/components/Card/Card.svelte';
+  import { inputStateStore, getStateString } from '$lib/util/state';
+  import {
+    addHistoryEntry,
+    historyModeStore,
+    clearHistoryData,
+    getPreviousState,
+    historyStore,
+    loaderHistoryStore,
+    restoreHistory
+  } from './history';
+  import { notify, prompt } from '$lib/util/notify';
+  import { onMount } from 'svelte';
+  import { get } from 'svelte/store';
+  import moment from 'moment';
+  import type { HistoryType, State, Tab } from '$lib/types';
+  import { logEvent } from '$lib/util/stats';
 
-	const HISTORY_SAVE_INTERVAL = 60000;
+  const HISTORY_SAVE_INTERVAL = 60000;
 
-	const tabSelectHandler = (message: CustomEvent<Tab>) => {
-		historyModeStore.set(message.detail.id as HistoryType);
-	};
-	let tabs: Tab[] = [
-		{
-			id: 'manual',
-			title: 'Saved',
-			icon: 'far fa-bookmark'
-		},
-		{
-			id: 'auto',
-			title: 'Timeline',
-			icon: 'fas fa-history'
-		}
-	];
+  const tabSelectHandler = (message: CustomEvent<Tab>) => {
+    historyModeStore.set(message.detail.id as HistoryType);
+  };
+  let tabs: Tab[] = [
+    {
+      id: 'manual',
+      title: 'Saved',
+      icon: 'far fa-bookmark'
+    },
+    {
+      id: 'auto',
+      title: 'Timeline',
+      icon: 'fas fa-history'
+    }
+  ];
 
-	const saveHistory = (auto = false) => {
-		const currentState: string = getStateString();
-		const previousState: string = getPreviousState(auto);
-		if (previousState !== currentState) {
-			addHistoryEntry({
-				state: $codeStore,
-				time: Date.now(),
-				type: auto ? 'auto' : 'manual'
-			});
-		} else if (!auto) {
-			notify('State already saved.');
-		}
-	};
+  const downloadHistory = () => {
+    const data = get(historyStore);
+    const blob = new Blob([JSON.stringify(data)], { type: 'application/json' });
+    const url = URL.createObjectURL(blob);
+    const a = document.createElement('a');
+    a.href = url;
+    a.download = `mermaid-history-${moment().format('YYYY-MM-DD-HHmmss')}.json`;
+    a.click();
+    URL.revokeObjectURL(url);
+    logEvent('history', {
+      action: 'download'
+    });
+  };
 
-	const clearHistory = (date?: number): void => {
-		if (!date && !prompt('Clear all saved items?')) {
-			return;
-		}
-		clearHistoryData(date);
-	};
+  const uploadHistory = () => {
+    const input = document.createElement('input');
+    input.type = 'file';
+    input.accept = 'application/json';
+    input.addEventListener('change', ({ target }: Event) => {
+      const file = (<HTMLInputElement>target).files[0];
+      if (!file) {
+        return;
+      }
+      const reader = new FileReader();
+      reader.onload = (e) => {
+        const data = JSON.parse(e.target.result as string);
+        restoreHistory(data);
+      };
+      reader.readAsText(file);
+    });
+    input.click();
+  };
 
-	const restoreHistory = (state: State): void => {
-		codeStore.set({ ...state, updateEditor: true, updateDiagram: true });
-	};
+  const saveHistory = (auto = false) => {
+    const currentState: string = getStateString();
+    const previousState: string = getPreviousState(auto);
+    if (previousState !== currentState) {
+      addHistoryEntry({
+        state: $inputStateStore,
+        time: Date.now(),
+        type: auto ? 'auto' : 'manual'
+      });
+    } else if (!auto) {
+      notify('State already saved.');
+    }
+  };
 
-	const relativeTime = (time: number) => {
-		const t = new Date(time);
-		return `${new Date(t).toLocaleString()} (${moment(t).fromNow()})`;
-	};
+  const clearHistory = (id?: string): void => {
+    if (!id && !prompt('Clear all saved items?')) {
+      return;
+    }
+    clearHistoryData(id);
+  };
 
-	onMount(() => {
-		historyModeStore.set('manual');
-		setInterval(() => {
-			saveHistory(true);
-		}, HISTORY_SAVE_INTERVAL);
-	});
+  const restoreHistoryItem = (state: State): void => {
+    inputStateStore.set({ ...state, updateDiagram: true });
+  };
 
-	loaderHistoryStore.subscribe((entries) => {
-		if (entries.length > 0 && tabs.length === 2) {
-			tabs = [
-				{
-					id: 'loader',
-					title: 'Revisions',
-					icon: 'fab fa-git-alt'
-				},
-				...tabs
-			];
-			historyModeStore.set('loader');
-		}
-	});
+  const relativeTime = (time: number) => {
+    const t = new Date(time);
+    return `${new Date(t).toLocaleString()} (${moment(t).fromNow()})`;
+  };
 
-	let isOpen = false;
+  onMount(() => {
+    historyModeStore.set('manual');
+    setInterval(() => {
+      saveHistory(true);
+    }, HISTORY_SAVE_INTERVAL);
+  });
+
+  loaderHistoryStore.subscribe((entries) => {
+    if (entries.length > 0 && tabs.length === 2) {
+      tabs = [
+        {
+          id: 'loader',
+          title: 'Revisions',
+          icon: 'fab fa-git-alt'
+        },
+        ...tabs
+      ];
+      historyModeStore.set('loader');
+    }
+  });
+
+  let isOpen = false;
 </script>
 
 <Card on:select={tabSelectHandler} bind:isOpen {tabs} title="History">
-	<div slot="actions">
-		<button
-			id="saveHistory"
-			class="btn btn-xs btn-success w-12"
-			on:click|stopPropagation={() => saveHistory()}
-			title="Save current state"><i class="far fa-save" /></button>
-		{#if $historyModeStore !== 'loader'}
-			<button
-				id="clearHistory"
-				class="btn btn-xs btn-error w-12"
-				on:click|stopPropagation={() => clearHistory()}
-				title="Delete all saved states"><i class="fas fa-trash-alt" /></button>
-		{/if}
-	</div>
-	<ul class="p-2 space-y-2 overflow-auto h-56" id="historyList">
-		{#if $historyStore.length > 0}
-			{#each $historyStore as { state, time, name, url, type }}
-				<li class="rounded p-2 shadow flex-col">
-					<div class="flex">
-						<div class="flex-1">
-							<div class="flex flex-col text-base-content">
-								{#if url}
-									<a
-										href={url}
-										target="_blank"
-										title="Open revision in new tab"
-										class="hover:underline text-blue-500">{name}</a>
-								{:else}
-									<span>{name}</span>
-								{/if}
-								<span class="text-gray-400 text-sm">{relativeTime(time)}</span>
-							</div>
-						</div>
-						<div class="flex gap-2 content-center">
-							<button class="btn btn-success" on:click={() => restoreHistory(state)}
-								><i class="fas fa-undo mr-1" />Restore</button>
-							{#if type !== 'loader'}
-								<button class="btn btn-error" on:click={() => clearHistory(time)}
-									><i class="fas fa-trash-alt mr-1" />Delete</button>
-							{/if}
-						</div>
-					</div>
-				</li>
-			{/each}
-		{:else}
-			<div class="m-2">
-				No items in History<br />
-				Click the Save button to save current state and restore it later.<br />
-				Timeline will automatically be saved every minute.
-			</div>
-		{/if}
-	</ul>
+  <div slot="actions">
+    <button
+      id="uploadHistory"
+      class="btn btn-xs btn-secondary w-12"
+      on:click|stopPropagation={() => uploadHistory()}
+      title="Upload history"><i class="fa fa-upload" /></button>
+    {#if $historyStore.length > 0}
+      <button
+        id="downloadHistory"
+        class="btn btn-xs btn-secondary w-12"
+        on:click|stopPropagation={() => downloadHistory()}
+        title="Download history"><i class="fa fa-download" /></button>
+    {/if}
+    |
+    <button
+      id="saveHistory"
+      class="btn btn-xs btn-success w-12"
+      on:click|stopPropagation={() => saveHistory()}
+      title="Save current state"><i class="far fa-save" /></button>
+    {#if $historyModeStore !== 'loader'}
+      <button
+        id="clearHistory"
+        class="btn btn-xs btn-error w-12"
+        on:click|stopPropagation={() => clearHistory()}
+        title="Delete all saved states"><i class="fas fa-trash-alt" /></button>
+    {/if}
+  </div>
+  <ul class="p-2 space-y-2 overflow-auto h-56" id="historyList">
+    {#if $historyStore.length > 0}
+      {#each $historyStore as { id, state, time, name, url, type }}
+        <li class="rounded p-2 shadow flex-col">
+          <div class="flex">
+            <div class="flex-1">
+              <div class="flex flex-col text-base-content">
+                {#if url}
+                  <a
+                    href={url}
+                    target="_blank"
+                    rel="noreferrer"
+                    title="Open revision in new tab"
+                    class="hover:underline text-blue-500">{name}</a>
+                {:else}
+                  <span>{name}</span>
+                {/if}
+                <span class="text-gray-400 text-sm">{relativeTime(time)}</span>
+              </div>
+            </div>
+            <div class="flex gap-2 content-center">
+              <button class="btn btn-success" on:click={() => restoreHistoryItem(state)}
+                ><i class="fas fa-undo mr-1" />Restore</button>
+              {#if type !== 'loader'}
+                <button class="btn btn-error" on:click={() => clearHistory(id)}
+                  ><i class="fas fa-trash-alt mr-1" />Delete</button>
+              {/if}
+            </div>
+          </div>
+        </li>
+      {/each}
+    {:else}
+      <div class="m-2">
+        No items in History<br />
+        Click the Save button to save current state and restore it later.<br />
+        Timeline will automatically be saved every minute.
+      </div>
+    {/if}
+  </ul>
 </Card>

src/lib/components/history/history.test.ts

@@ -0,0 +1,120 @@
+import type { HistoryEntry } from '$lib/types';
+import { describe, it, expect } from 'vitest';
+import {
+  addHistoryEntry,
+  injectHistoryIDs,
+  clearHistoryData,
+  historyModeStore,
+  historyStore
+} from './history';
+import { defaultState } from '$lib/util/state';
+import { get } from 'svelte/store';
+
+describe('history', () => {
+  it('should handle saving individual history entry', () => {
+    expect(window.localStorage.getItem('manualHistoryStore')).toBe('[]');
+    expect(window.localStorage.getItem('autoHistoryStore')).toBe('[]');
+
+    addHistoryEntry({
+      state: defaultState,
+      time: 12345,
+      type: 'manual'
+    });
+
+    const [manualEntry]: HistoryEntry[] = JSON.parse(
+      window.localStorage.getItem('manualHistoryStore')
+    );
+
+    expect(manualEntry.time).toBe(12345);
+    expect(manualEntry.type).toBe('manual');
+    expect(manualEntry.name).not.toBeNull();
+    expect(manualEntry.state).not.toBeNull();
+
+    addHistoryEntry({
+      state: defaultState,
+      time: 54321,
+      type: 'auto'
+    });
+
+    const [autoEntry]: HistoryEntry[] = JSON.parse(window.localStorage.getItem('autoHistoryStore'));
+
+    expect(autoEntry.time).toBe(54321);
+    expect(autoEntry.type).toBe('auto');
+    expect(autoEntry.name).not.toBeNull();
+    expect(autoEntry.state).not.toBeNull();
+
+    historyModeStore.set('manual');
+    clearHistoryData();
+    historyModeStore.set('auto');
+    clearHistoryData();
+    expect(window.localStorage.getItem('manualHistoryStore')).toBe('[]');
+    expect(window.localStorage.getItem('autoHistoryStore')).toBe('[]');
+  });
+
+  it('should clear history entries', () => {
+    addHistoryEntry({
+      state: defaultState,
+      time: 12345,
+      type: 'manual'
+    });
+    addHistoryEntry({
+      state: { ...defaultState, code: 'graph TD\\n    A[Christmas] -->|Get money| B(Go shopping)' },
+      time: 123456,
+      type: 'manual'
+    });
+
+    historyModeStore.set('manual');
+    const store: HistoryEntry[] = get(historyStore);
+    expect(store.length).toBe(2);
+    clearHistoryData(store[1].id);
+    expect(get(historyStore).length).toBe(1);
+    clearHistoryData();
+    expect(get(historyStore).length).toBe(0);
+
+    historyModeStore.set('auto');
+    addHistoryEntry({
+      state: defaultState,
+      time: 54321,
+      type: 'auto'
+    });
+    addHistoryEntry({
+      state: { ...defaultState, code: 'graph TD\\n    A[Christmas] -->|Get money| B(Go shopping)' },
+      time: 654321,
+      type: 'auto'
+    });
+    expect(get(historyStore).length).toBe(2);
+    clearHistoryData();
+    expect(get(historyStore).length).toBe(0);
+    // Test calling when history is empty
+    clearHistoryData();
+    expect(get(historyStore).length).toBe(0);
+  });
+});
+
+describe('history migration', () => {
+  it('should inject history IDs as migration', () => {
+    window.localStorage.setItem(
+      'manualHistoryStore',
+      '[{"state":{"code":"graph TD\\n    A[Halloween] -->|Get money| B(Go shopping)","mermaid":"{\\n  \\"theme\\": \\"dark\\"\\n}","autoSync":true,"updateDiagram":false},"time":0,"type":"manual","name":"hollow-art"},{"state":{"code":"graph TD\\n    A[Christmas] -->|Get money| B(Go shopping)","mermaid":"{\\n  \\"theme\\": \\"dark\\"\\n}","autoSync":true,"updateDiagram":true},"time":0,"type":"manual","name":"helpful-ocean"}]'
+    );
+    window.localStorage.setItem(
+      'autoHistoryStore',
+      '[{"state":{"code":"graph TD\\n    A[New Year] -->|Get money| B(Go shopping)","mermaid":"{\\n  \\"theme\\": \\"dark\\"\\n}","autoSync":true,"updateDiagram":false},"time":0,"type":"auto","name":"barking-dog"},{"state":{"code":"graph TD\\n    A[Christmas] -->|Get money| B(Go shopping)","mermaid":"{\\n  \\"theme\\": \\"dark\\"\\n}","autoSync":true,"updateDiagram":true},"time":0,"type":"manual","name":"needy-mosquito"}]'
+    );
+    let manualHistoryStore: HistoryEntry[] = JSON.parse(
+      window.localStorage.getItem('manualHistoryStore')
+    );
+    let autoHistoryStore: HistoryEntry[] = JSON.parse(
+      window.localStorage.getItem('autoHistoryStore')
+    );
+    expect(manualHistoryStore.every(({ id }) => id !== undefined)).toBe(false);
+    expect(autoHistoryStore.every(({ id }) => id !== undefined)).toBe(false);
+
+    injectHistoryIDs();
+
+    manualHistoryStore = JSON.parse(window.localStorage.getItem('manualHistoryStore'));
+    autoHistoryStore = JSON.parse(window.localStorage.getItem('autoHistoryStore'));
+    expect(manualHistoryStore.every(({ id }) => id !== undefined)).toBe(true);
+    expect(autoHistoryStore.every(({ id }) => id !== undefined)).toBe(true);
+  });
+});

src/lib/components/history/history.ts

@@ -1,77 +1,141 @@
 import { derived, writable, get } from 'svelte/store';
 import type { Readable, Writable } from 'svelte/store';
-import { persist, localStorage } from '@macfja/svelte-persistent-store';
+import { persist, localStorage } from '$lib/util/persist';
 import { generateSlug } from 'random-word-slugs';
-import type { HistoryEntry, HistoryType } from '$lib/types';
+import type { HistoryEntry, HistoryType, Optional } from '$lib/types';
+import { v4 as uuidV4 } from 'uuid';
+import { logEvent } from '$lib/util/stats';
 
 const MAX_AUTO_HISTORY_LENGTH = 30;
 
 export const historyModeStore: Writable<HistoryType> = persist(
-	writable('manual'),
-	localStorage(),
-	'autoHistoryMode'
+  writable('manual'),
+  localStorage(),
+  'autoHistoryMode'
 );
 
 const autoHistoryStore: Writable<HistoryEntry[]> = persist(
-	writable([]),
-	localStorage(),
-	'autoHistoryStore'
+  writable([]),
+  localStorage(),
+  'autoHistoryStore'
 );
 
 const manualHistoryStore: Writable<HistoryEntry[]> = persist(
-	writable([]),
-	localStorage(),
-	'manualHistoryStore'
+  writable([]),
+  localStorage(),
+  'manualHistoryStore'
 );
 
 export const loaderHistoryStore: Writable<HistoryEntry[]> = writable([] as HistoryEntry[]);
 
 export const historyStore: Readable<HistoryEntry[]> = derived(
-	[historyModeStore, autoHistoryStore, manualHistoryStore, loaderHistoryStore],
-	([historyMode, autoHistories, manualHistories, loadedHistories], set) => {
-		if (historyMode === 'auto') {
-			set(autoHistories);
-		} else if (historyMode === 'manual') {
-			set(manualHistories);
-		} else if (historyMode === 'loader') {
-			set(loadedHistories);
-		} else {
-			set(autoHistories);
-		}
-	}
+  [historyModeStore, autoHistoryStore, manualHistoryStore, loaderHistoryStore],
+  ([historyMode, autoHistories, manualHistories, loadedHistories], set) => {
+    if (historyMode === 'auto') {
+      set(autoHistories);
+    } else if (historyMode === 'manual') {
+      set(manualHistories);
+    } else if (historyMode === 'loader') {
+      set(loadedHistories);
+    } else {
+      set(autoHistories);
+    }
+  }
 );
 
-export const addHistoryEntry = (entry: HistoryEntry): void => {
-	if (entry.type === 'loader') {
-		loaderHistoryStore.update((entries) => [entry, ...entries]);
-		return;
-	}
-	entry.name = generateSlug(2);
-	if (entry.type !== 'auto') {
-		manualHistoryStore.update((entries) => [entry, ...entries]);
-		return;
-	}
-	autoHistoryStore.update((entries) => {
-		if (entries.length === MAX_AUTO_HISTORY_LENGTH) {
-			entries.pop();
-		}
-		return [entry, ...entries];
-	});
+export const addHistoryEntry = (entryToAdd: Optional<HistoryEntry, 'id'>): void => {
+  const entry: HistoryEntry = {
+    ...entryToAdd,
+    id: uuidV4()
+  };
+
+  if (entry.type === 'loader') {
+    loaderHistoryStore.update((entries) => [entry, ...entries]);
+    return;
+  }
+
+  if (!entry.name) {
+    entry.name = generateSlug(2);
+  }
+
+  if (entry.type === 'auto') {
+    autoHistoryStore.update((entries) => {
+      if (entries.length >= MAX_AUTO_HISTORY_LENGTH) {
+        entries = entries.slice(0, MAX_AUTO_HISTORY_LENGTH - 1);
+      }
+      return [entry, ...entries];
+    });
+  } else if (entry.type === 'manual') {
+    manualHistoryStore.update((entries) => [entry, ...entries]);
+    logEvent('history', { action: 'save' });
+  }
 };
 
-export const clearHistoryData = (time?: number): void => {
-	(get(historyModeStore) === 'auto' ? autoHistoryStore : manualHistoryStore).update((entries) => {
-		if (get(historyModeStore) !== 'loader') {
-			entries = entries.filter((entry) => time && entry.time != time);
-		}
-		return entries;
-	});
+export const clearHistoryData = (idToClear?: string): void => {
+  (get(historyModeStore) === 'auto' ? autoHistoryStore : manualHistoryStore).update((entries) => {
+    if (get(historyModeStore) !== 'loader') {
+      entries = entries.filter(({ id }) => idToClear && id != idToClear);
+      logEvent('history', { action: 'clear', type: idToClear ? 'single' : 'all' });
+    }
+    return entries;
+  });
 };
 
 export const getPreviousState = (auto: boolean): string => {
-	const entries = get(auto ? autoHistoryStore : manualHistoryStore);
-	if (entries.length > 0) {
-		return JSON.stringify(entries[0].state);
-	}
-	return '';
+  const entries = get(auto ? autoHistoryStore : manualHistoryStore);
+  if (entries.length > 0) {
+    return JSON.stringify(entries[0].state);
+  }
+  return '';
+};
+
+export const restoreHistory = (data: HistoryEntry[]) => {
+  const entries = data.filter(validateEntry);
+  const invalidEntryCount = data.length - entries.length;
+  if (invalidEntryCount > 0) {
+    console.error(`${invalidEntryCount} invalid history entries were removed.`);
+    console.error(data);
+  }
+  if (entries.length > 0) {
+    let entryCount = 0;
+    (entries[0].type === 'auto' ? autoHistoryStore : manualHistoryStore).update((existing) => {
+      const existingIDs = new Set(existing.map(({ id }) => id));
+      const newEntries = entries.filter(({ id }) => !existingIDs.has(id));
+      entryCount = newEntries.length;
+      const combined = [...existing, ...newEntries];
+      combined.sort((a, b) => b.time - a.time);
+      return combined;
+    });
+
+    alert(
+      `${entryCount} entries restored. ${invalidEntryCount} invalid, ${
+        entries.length - entryCount
+      } duplicates.`
+    );
+    logEvent('history', {
+      action: 'restore',
+      success: entryCount,
+      invalid: invalidEntryCount,
+      duplicates: entries.length - entryCount
+    });
+  } else {
+    alert('No valid entries found.');
+  }
+};
+
+export const injectHistoryIDs = (): void => {
+  const setIDs = (entries: HistoryEntry[]) => {
+    for (const entry of entries) {
+      if (!entry.id) {
+        entry.id = uuidV4();
+      }
+    }
+    return entries;
+  };
+  autoHistoryStore.update(setIDs);
+  manualHistoryStore.update(setIDs);
+};
+
+const validateEntry = (entry: HistoryEntry): boolean => {
+  return entry.type && entry.state && entry.time && true;
 };

src/lib/components/navbar.svelte

@@ -1,82 +1,82 @@
 <script context="module">
-	import { version } from 'mermaid/package.json';
-	import { analytics } from '$lib/util/stats';
-	analytics?.track('version', {
-		mermaidVersion: version
-	});
+  import { version } from 'mermaid/package.json';
+  import { analytics } from '$lib/util/stats';
+  analytics?.track('version', {
+    mermaidVersion: version
+  });
 </script>
 
 <script lang="ts">
-	import Theme from './theme.svelte';
+  import Theme from './Theme.svelte';
 
-	interface Link {
-		title: string;
-		href: string;
-		icon?: string;
-	}
-	const links: Link[] = [
-		{
-			title: 'Documentation',
-			href: 'https://mermaid-js.github.io/mermaid/#/n00b-gettingStarted'
-		},
-		{
-			title: 'Tutorial',
-			href: 'https://github.com/mermaid-js/mermaid/blob/develop/docs/Tutorials.md'
-		},
-		{
-			title: 'Mermaid',
-			href: 'https://github.com/mermaid-js/mermaid'
-		},
-		{
-			title: 'CLI',
-			href: 'https://github.com/mermaid-js/mermaid-cli'
-		},
-		{
-			title: '',
-			href: 'https://github.com/mermaid-js/mermaid-live-editor',
-			icon: 'fab fa-github fa-lg'
-		}
-	];
+  interface Link {
+    title: string;
+    href: string;
+    icon?: string;
+  }
+  const links: Link[] = [
+    {
+      title: 'Documentation',
+      href: 'https://mermaid-js.github.io/mermaid/#/n00b-gettingStarted'
+    },
+    {
+      title: 'Tutorial',
+      href: 'https://github.com/mermaid-js/mermaid/blob/develop/docs/Tutorials.md'
+    },
+    {
+      title: 'Mermaid',
+      href: 'https://github.com/mermaid-js/mermaid'
+    },
+    {
+      title: 'CLI',
+      href: 'https://github.com/mermaid-js/mermaid-cli'
+    },
+    {
+      title: '',
+      href: 'https://github.com/mermaid-js/mermaid-live-editor',
+      icon: 'fab fa-github fa-lg'
+    }
+  ];
 </script>
 
-<div class="navbar mb-2 shadow-lg bg-primary">
-	<div class="flex-1 px-2 mx-2">
-		<span class="text-lg font-bold">
-			<a href="/">Mermaid<span class="text-xs font-thin">v{version}</span> Live Editor</a>
-		</span>
-	</div>
-	<label for="menu-toggle" class="pointer-cursor lg:hidden block"
-		><svg
-			class="fill-current "
-			xmlns="http://www.w3.org/2000/svg"
-			width="20"
-			height="20"
-			viewBox="0 0 20 20"
-			><title>Menu</title><path d="M0 3h20v2H0V3zm0 6h20v2H0V9zm0 6h20v2H0v-2z" /></svg
-		></label>
-	<input class="hidden" type="checkbox" id="menu-toggle" />
+<div class="navbar shadow-lg bg-primary p-0">
+  <div class="flex-1 px-2 mx-2">
+    <span class="text-lg font-bold">
+      <a href="/">Mermaid<span class="text-xs font-thin">v{version}</span> Live Editor</a>
+    </span>
+  </div>
+  <label for="menu-toggle" class="pointer-cursor lg:hidden block"
+    ><svg
+      class="fill-current "
+      xmlns="http://www.w3.org/2000/svg"
+      width="20"
+      height="20"
+      viewBox="0 0 20 20"
+      ><title>Menu</title><path d="M0 3h20v2H0V3zm0 6h20v2H0V9zm0 6h20v2H0v-2z" /></svg
+    ></label>
+  <input class="hidden" type="checkbox" id="menu-toggle" />
 
-	<Theme />
-	<div class="hidden lg:flex lg:items-center lg:w-auto w-full" id="menu">
-		<ul class="lg:flex items-center justify-between text-base pt-4 lg:pt-0">
-			{#each links as { title, href, icon }}
-				<li>
-					<a class="btn btn-ghost" target="_blank" {href}>
-						{#if icon}
-							<i class={icon} />
-						{/if}
-						{title}</a>
-				</li>
-			{/each}
-		</ul>
-	</div>
+  <Theme />
+  <div class="hidden lg:flex lg:items-center lg:w-auto w-full" id="menu">
+    <ul class="lg:flex items-center justify-between text-base pt-4 lg:pt-0">
+      {#each links as { title, href, icon }}
+        <li>
+          <a class="btn btn-ghost" target="_blank" rel="noreferrer" {href}>
+            {#if icon}
+              <i class={icon} />
+            {/if}
+            {title}</a>
+        </li>
+      {/each}
+    </ul>
+  </div>
 </div>
 
 <style>
-	#menu-toggle:checked + #menu {
-		display: block;
-	}
-	.navbar {
-		z-index: 10000;
-	}
+  #menu-toggle:checked + #menu {
+    display: block;
+  }
+  .navbar {
+    z-index: 10000;
+  }
 </style>

src/lib/components/preset.svelte

@@ -1,21 +1,21 @@
 <script lang="ts">
-	import { updateCode } from '$lib/util/state';
-	import Card from '$lib/components/card/card.svelte';
+  import { updateCode } from '$lib/util/state';
+  import Card from '$lib/components/Card/Card.svelte';
+  import { logEvent } from '$lib/util/stats';
 
-	const samples = {
-		'Flow Chart': `graph TD
+  const samples = {
+    Flow: `graph TD
     A[Christmas] -->|Get money| B(Go shopping)
     B --> C{Let me think}
     C -->|One| D[Laptop]
     C -->|Two| E[iPhone]
     C -->|Three| F[fa:fa-car Car]`,
-		'Sequence Diagram': `sequenceDiagram
+    Sequence: `sequenceDiagram
     Alice->>+John: Hello John, how are you?
     Alice->>+John: John, can you hear me?
     John-->>-Alice: Hi Alice, I can hear you!
-    John-->>-Alice: I feel great!
-            `,
-		'Class Diagram': `classDiagram
+    John-->>-Alice: I feel great!`,
+    Class: `classDiagram
     Animal <|-- Duck
     Animal <|-- Fish
     Animal <|-- Zebra
@@ -35,17 +35,15 @@
     class Zebra{
       +bool is_wild
       +run()
-    }
-            `,
-		'State Diagram': `stateDiagram-v2
+    }`,
+    State: `stateDiagram-v2
     [*] --> Still
     Still --> [*]
     Still --> Moving
     Moving --> Still
     Moving --> Crash
-    Crash --> [*]
-            `,
-		'Gantt Chart': `gantt
+    Crash --> [*]`,
+    Gantt: `gantt
     title A Gantt Diagram
     dateFormat  YYYY-MM-DD
     section Section
@@ -53,24 +51,21 @@
     Another task     :after a1  , 20d
     section Another
     Task in sec      :2014-01-12  , 12d
-    another task      : 24d
-            `,
-		'Pie Chart': `pie title Pets adopted by volunteers
+    another task      : 24d`,
+    Pie: `pie title Pets adopted by volunteers
     "Dogs" : 386
     "Cats" : 85
-    "Rats" : 15
-            `,
-		'ER Diagram': `erDiagram
-          CUSTOMER }|..|{ DELIVERY-ADDRESS : has
-          CUSTOMER ||--o{ ORDER : places
-          CUSTOMER ||--o{ INVOICE : "liable for"
-          DELIVERY-ADDRESS ||--o{ ORDER : receives
-          INVOICE ||--|{ ORDER : covers
-          ORDER ||--|{ ORDER-ITEM : includes
-          PRODUCT-CATEGORY ||--|{ PRODUCT : contains
-          PRODUCT ||--o{ ORDER-ITEM : "ordered in"
-            `,
-		'User Journey': `  journey
+    "Rats" : 15`,
+    ER: `erDiagram
+    CUSTOMER }|..|{ DELIVERY-ADDRESS : has
+    CUSTOMER ||--o{ ORDER : places
+    CUSTOMER ||--o{ INVOICE : "liable for"
+    DELIVERY-ADDRESS ||--o{ ORDER : receives
+    INVOICE ||--|{ ORDER : covers
+    ORDER ||--|{ ORDER-ITEM : includes
+    PRODUCT-CATEGORY ||--|{ PRODUCT : contains
+    PRODUCT ||--o{ ORDER-ITEM : "ordered in"`,
+    'User Journey': `journey
     title My working day
     section Go to work
       Make tea: 5: Me
@@ -78,20 +73,72 @@
       Do work: 1: Me, Cat
     section Go home
       Go downstairs: 5: Me
-      Sit down: 3: Me
-      `
-	};
+      Sit down: 3: Me`,
+    Git: `gitGraph
+    commit
+    commit
+    branch develop
+    checkout develop
+    commit
+    commit
+    checkout main
+    merge develop
+    commit
+    commit`,
+    Mindmap: `mindmap
+  root((mindmap))
+    Origins
+      Long history
+      ::icon(fa fa-book)
+      Popularisation
+        British popular psychology author Tony Buzan
+    Research
+      On effectivness<br/>and features
+      On Automatic creation
+        Uses
+            Creative techniques
+            Strategic planning
+            Argument mapping
+    Tools
+      Pen and paper
+      Mermaid`
+  };
 
-	const loadSampleDiagram = (diagramType: string): void => {
-		updateCode(samples[diagramType], true, true);
-	};
+  const loadSampleDiagram = (diagramType: string): void => {
+    updateCode(samples[diagramType], {
+      updateDiagram: true,
+      resetPanZoom: true
+    });
+    logEvent('loadSampleDiagram', { diagramType });
+  };
+
+  // Adding in this array will add an icon to the preset menu
+  const newDiagrams: Array<keyof typeof samples> = ['Mindmap'];
+  const diagramOrder: Array<keyof typeof samples> = [
+    'Sequence',
+    'Flow',
+    'Class',
+    'State',
+    'ER',
+    'Gantt',
+    'User Journey',
+    'Git',
+    'Pie',
+    'Mindmap'
+  ];
 </script>
 
 <Card title="Sample Diagrams" isOpen={false}>
-	<div class="flex gap-2 flex-wrap p-2">
-		{#each Object.keys(samples) as sample}
-			<button class="btn btn-primary normal-case btn-sm" on:click={() => loadSampleDiagram(sample)}
-				>{sample}</button>
-		{/each}
-	</div>
+  <div class="flex flex-wrap p-2 gap-2">
+    {#each diagramOrder as sample}
+      <button
+        class="btn btn-sm btn-primary w-28 normal-case flex-grow"
+        on:click={() => loadSampleDiagram(sample)}>
+        {sample}
+        {#if newDiagrams.includes(sample)}
+          <span class="ml-2 fa fa-heart" />
+        {/if}
+      </button>
+    {/each}
+  </div>
 </Card>

src/lib/components/theme.svelte

@@ -1,59 +1,64 @@
 <script>
-	import { setTheme, themeStore } from '$lib/util/theme';
+  import { setTheme, themeStore } from '$lib/util/theme';
 
-	const themes = [
-		'🌝  light',
-		'🌚  dark',
-		'🧁  cupcake',
-		'🐝  bumblebee',
-		'✳️  emerald',
-		'🏢  corporate',
-		'🌃  synthwave',
-		'👴  retro',
-		'🤖  cyberpunk',
-		'🌸  valentine',
-		'🎃  halloween',
-		'🌷  garden',
-		'🌲  forest',
-		'🐟  aqua',
-		'👓  lofi',
-		'🖍  pastel',
-		'🧚‍♀️  fantasy',
-		'📝  wireframe',
-		'🏴  black',
-		'💎  luxury',
-		'🧛‍♂️  dracula'
-	];
+  const themes = [
+    '🌝 light',
+    '🌚 dark',
+    '🧁 cupcake',
+    '🐝 bumblebee',
+    '✳️ emerald',
+    '🏢 corporate',
+    '🌃 synthwave',
+    '👴 retro',
+    '🤖 cyberpunk',
+    '🌸 valentine',
+    '🎃 halloween',
+    '🌷 garden',
+    '🌲 forest',
+    '🐟 aqua',
+    '👓 lofi',
+    '🖍 pastel',
+    '🧚‍♀️ fantasy',
+    '📝 wireframe',
+    '🏴 black',
+    '💎 luxury',
+    '🧛‍♂️ dracula'
+  ];
 </script>
 
 <div class="hidden lg:block dropdown">
-	<div tabindex="0" class="btn btn-ghost ">
-		<svg
-			xmlns="http://www.w3.org/2000/svg"
-			fill="none"
-			viewBox="0 0 24 24"
-			class="inline-block w-6 h-6 stroke-current md:mr-2"
-			><path
-				stroke-linecap="round"
-				stroke-linejoin="round"
-				stroke-width="2"
-				d="M7 21a4 4 0 01-4-4V5a2 2 0 012-2h4a2 2 0 012 2v12a4 4 0 01-4 4zm0 0h12a2 2 0 002-2v-4a2 2 0 00-2-2h-2.343M11 7.343l1.657-1.657a2 2 0 012.828 0l2.829 2.829a2 2 0 010 2.828l-8.486 8.485M7 17h.01" /></svg>
-		<span class="hidden md:inline"> Change Theme </span>
-		<svg
-			xmlns="http://www.w3.org/2000/svg"
-			viewBox="0 0 1792 1792"
-			class="inline-block w-4 h-4 ml-1 fill-current"
-			><path
-				d="M1395 736q0 13-10 23l-466 466q-10 10-23 10t-23-10l-466-466q-10-10-10-23t10-23l50-50q10-10 23-10t23 10l393 393 393-393q10-10 23-10t23 10l50 50q10 10 10 23z" /></svg>
-	</div>
-	<div
-		class="mt-14 overflow-y-auto shadow-2xl top-px dropdown-content h-96 w-56 bg-base-200 text-base-content">
-		<ul tabindex="0" class="p-4 menu compact">
-			{#each themes as theme}
-				<li class={theme.includes($themeStore.theme) ? 'bordered' : ''}>
-					<span class="btn btn-ghost justify-start" on:click={() => setTheme(theme)}>{theme}</span>
-				</li>
-			{/each}
-		</ul>
-	</div>
+  <!-- svelte-ignore a11y-no-noninteractive-tabindex -->
+  <div tabindex="0" class="btn btn-ghost ">
+    <svg
+      xmlns="http://www.w3.org/2000/svg"
+      fill="none"
+      viewBox="0 0 24 24"
+      class="inline-block w-6 h-6 stroke-current md:mr-2"
+      ><path
+        stroke-linecap="round"
+        stroke-linejoin="round"
+        stroke-width="2"
+        d="M7 21a4 4 0 01-4-4V5a2 2 0 012-2h4a2 2 0 012 2v12a4 4 0 01-4 4zm0 0h12a2 2 0 002-2v-4a2 2 0 00-2-2h-2.343M11 7.343l1.657-1.657a2 2 0 012.828 0l2.829 2.829a2 2 0 010 2.828l-8.486 8.485M7 17h.01" /></svg>
+    <span class="hidden md:inline"> Change Theme </span>
+    <svg
+      xmlns="http://www.w3.org/2000/svg"
+      viewBox="0 0 1792 1792"
+      class="inline-block w-4 h-4 ml-1 fill-current"
+      ><path
+        d="M1395 736q0 13-10 23l-466 466q-10 10-23 10t-23-10l-466-466q-10-10-10-23t10-23l50-50q10-10 23-10t23 10l393 393 393-393q10-10 23-10t23 10l50 50q10 10 10 23z" /></svg>
+  </div>
+  <div
+    class="mt-14 overflow-y-auto shadow-2xl top-px dropdown-content h-96 w-56 bg-base-200 text-base-content">
+    <!-- svelte-ignore a11y-no-noninteractive-tabindex -->
+    <ul tabindex="0" class="p-4 menu compact">
+      {#each themes as theme}
+        <li class={theme.includes($themeStore.theme) ? 'bordered' : ''}>
+          <span
+            class="btn btn-ghost justify-start"
+            on:click={() => setTheme(theme)}
+            on:keypress={() => setTheme(theme)}>{theme}</span>
+        </li>
+      {/each}
+    </ul>
+  </div>
 </div>

src/lib/components/view.svelte

@@ -1,72 +1,157 @@
 <script lang="ts">
-	import { errorStore } from '$lib/util/error';
+  import { inputStateStore, stateStore, updateCodeStore } from '$lib/util/state';
+  import { onMount } from 'svelte';
+  import panzoom from 'svg-pan-zoom';
+  import type { State, ValidatedState } from '$lib/types';
+  import { logEvent } from '$lib/util/stats';
+  import { AsyncQueue, cmdKey } from '$lib/util/util';
+  import { render as renderDiagram } from '$lib/util/mermaid';
 
-	import { codeStore } from '$lib/util/state';
-	import { onMount } from 'svelte';
-	import mermaid from 'mermaid';
+  let code = '';
+  let config = '';
+  let container: HTMLDivElement;
+  let view: HTMLDivElement;
+  let error = false;
+  let outOfSync = false;
+  let hide = false;
+  let manualUpdate = true;
+  let panZoomEnabled = $stateStore.panZoom;
+  let pzoom: SvgPanZoom.Instance;
 
-	let code = '';
-	let config = '';
-	let container: HTMLDivElement;
-	let view: HTMLDivElement;
-	let error = false;
-	let outOfSync = false;
-	let manualUpdate = true;
-	onMount(() => {
-		codeStore.subscribe((state) => {
-			try {
-				if (container && state && (state.updateDiagram || state.autoSync)) {
-					if (!state.autoSync) {
-						$codeStore.updateDiagram = false;
-					}
-					outOfSync = false;
-					manualUpdate = true;
-					if (code === state.code && config === state.mermaid) {
-						// Do not render if there is no change in Code/Config
-						return;
-					}
-					code = state.code;
-					config = state.mermaid;
-					const scroll = view.parentElement.scrollTop;
-					delete container.dataset.processed;
-					mermaid.initialize(Object.assign({}, JSON.parse(state.mermaid)));
-					mermaid.render('graph-div', code, (svgCode) => {
-						container.innerHTML = svgCode;
-					});
-					view.parentElement.scrollTop = scroll;
-					error = false;
-				} else if (manualUpdate) {
-					manualUpdate = false;
-				} else {
-					outOfSync = true;
-				}
-			} catch (e) {
-				console.log('view fail', e);
-				error = true;
-			}
-		});
-		errorStore.subscribe((err) => {
-			if (typeof err === 'undefined') {
-				error = false;
-			} else {
-				error = true;
-				console.log('Error: ', err);
-			}
-		});
-	});
+  const handlePanZoomChange = () => {
+    const pan = pzoom.getPan();
+    const zoom = pzoom.getZoom();
+    updateCodeStore({ pan, zoom });
+    logEvent('panZoom');
+  };
+
+  const handlePanZoom = (state: State) => {
+    if (!state.panZoom) {
+      return;
+    }
+    hide = true;
+    pzoom?.destroy();
+    pzoom = undefined;
+    Promise.resolve().then(() => {
+      const graphDiv = document.getElementById('graph-div');
+      pzoom = panzoom(graphDiv, {
+        onPan: handlePanZoomChange,
+        onZoom: handlePanZoomChange,
+        controlIconsEnabled: true,
+        fit: true,
+        center: true
+      });
+      const { pan, zoom } = state;
+      if (pan !== undefined && zoom !== undefined && Number.isFinite(zoom)) {
+        pzoom.zoom(zoom);
+        pzoom.pan(pan);
+      }
+      hide = false;
+    });
+  };
+
+  const handleStateChange = async (state: ValidatedState) => {
+    if (state.error !== undefined) {
+      error = true;
+      return;
+    }
+    error = false;
+    try {
+      if (container && state && (state.updateDiagram || state.autoSync)) {
+        if (!state.autoSync) {
+          $inputStateStore.updateDiagram = false;
+        }
+        outOfSync = false;
+        manualUpdate = true;
+        // Do not render if there is no change in Code/Config/PanZoom
+        if (code === state.code && config === state.mermaid && panZoomEnabled === state.panZoom) {
+          return;
+        }
+        code = state.code;
+        config = state.mermaid;
+        panZoomEnabled = state.panZoom;
+        const scroll = view.parentElement.scrollTop;
+        delete container.dataset.processed;
+        await renderDiagram(
+          Object.assign({}, JSON.parse(state.mermaid)),
+          code,
+          'graph-div',
+          (svgCode, bindFunctions) => {
+            if (svgCode.length > 0) {
+              handlePanZoom(state);
+              container.innerHTML = svgCode;
+              // console.log(container.innerHTML);
+              const graphDiv = document.getElementById('graph-div');
+              graphDiv.setAttribute('height', '100%');
+              graphDiv.style.maxWidth = '100%';
+              if (bindFunctions) {
+                bindFunctions(graphDiv);
+              }
+            }
+          }
+        );
+        view.parentElement.scrollTop = scroll;
+        error = false;
+      } else if (manualUpdate) {
+        manualUpdate = false;
+      } else if (code !== state.code || config !== state.mermaid) {
+        outOfSync = true;
+      }
+    } catch (e) {
+      console.error('view fail', e);
+      error = true;
+    }
+  };
+
+  const q = new AsyncQueue(handleStateChange);
+
+  onMount(() => {
+    stateStore.subscribe(async (state) => {
+      await q.process(state);
+    });
+    window.addEventListener('resize', () => {
+      if ($stateStore.panZoom && pzoom) {
+        pzoom.resize();
+      }
+    });
+    console.log('View mounted');
+  });
 </script>
 
-<div id="view" bind:this={view} class="p-2" class:error class:outOfSync>
-	<div id="container" bind:this={container} class="flex-1 overflow-auto" />
+{#if (error && $stateStore.error instanceof Error) || outOfSync}
+  <div
+    class="absolute w-full p-2 z-10 {error
+      ? 'text-red-600'
+      : 'text-yellow-600'} bg-base-100 bg-opacity-80 text-center"
+    id="errorContainer">
+    {#if error}
+      {$stateStore.error}
+    {:else}
+      Diagram out of sync. <br />
+      Press <i class="fas fa-sync" /> (Sync button) or <kbd>{cmdKey} + Enter</kbd> to sync.
+    {/if}
+  </div>
+{/if}
+
+<div id="view" bind:this={view} class="p-2 h-full" class:error class:outOfSync>
+  <div id="container" bind:this={container} class="h-full overflow-auto" class:hide />
 </div>
 
 <style>
-	#view {
-		border: 1px solor darkred;
-		flex: 1;
-	}
-	.error,
-	.outOfSync {
-		opacity: 0.5;
-	}
+  #view {
+    flex: 1;
+  }
+
+  #container {
+    transition: visibility 0.3s;
+  }
+
+  .error,
+  .outOfSync {
+    opacity: 0.5;
+  }
+
+  .hide {
+    visibility: hidden;
+  }
 </style>

src/lib/types.d.ts

@@ -3,58 +3,84 @@
  * inside `global.d.ts` and removing `export` keyword
  */
 export interface Locals {
-	userid: string;
+  userid: string;
 }
 
-export interface EditorUpdateEvent {
-	text: string;
-}
-export interface EditorEvents {
-	update: EditorUpdateEvent;
+export interface MarkerData {
+  severity: number;
+  message: string;
+  source?: string;
+  startLineNumber: number;
+  startColumn: number;
+  endLineNumber: number;
+  endColumn: number;
 }
 
 export interface TabEvents {
-	select: Tab;
+  select: Tab;
 }
 
 export interface Tab {
-	id: string;
-	title: string;
-	icon: string;
+  id: string;
+  title: string;
+  icon: string;
 }
 
 export interface State {
-	code: string;
-	mermaid: string;
-	updateEditor: boolean;
-	updateDiagram: boolean;
-	autoSync: boolean;
-	loader?: LoaderConfig;
+  code: string;
+  mermaid: string;
+  updateDiagram: boolean;
+  autoSync: boolean;
+  editorMode?: EditorMode;
+  panZoom?: boolean;
+  pan?: { x: number; y: number };
+  zoom?: number;
+  loader?: LoaderConfig;
+}
+
+export interface ValidatedState extends State {
+  editorMode: EditorMode;
+  error: unknown;
+  errorMarkers: MarkerData[];
+  serialized: string;
 }
 
 export interface GistLoaderConfig {
-	url: string;
+  url: string;
 }
 
 export interface LoadingState {
-	loading: boolean;
-	message?: string;
+  loading: boolean;
+  message?: string;
 }
 export interface FileLoaderConfig {
-	codeURL: string;
-	configURL?: string;
+  codeURL: string;
+  configURL?: string;
 }
 export interface LoaderConfig {
-	type: 'gist' | 'files';
-	config: GistLoaderConfig | FileLoaderConfig;
+  type: 'gist' | 'files';
+  config: GistLoaderConfig | FileLoaderConfig;
 }
 export type HistoryType = 'auto' | 'manual' | 'loader';
-export interface HistoryEntry {
-	state: State;
-	time: number;
-	name?: string;
-	type: HistoryType;
-	url?: string;
+export type HistoryEntry = { id: string; state: State; time: number; url?: string } & (
+  | {
+      type: 'loader';
+      name: string;
+    }
+  | {
+      type: HistoryType;
+      name?: string;
+    }
+);
+
+export interface DocConfig {
+  [key: string]: {
+    code: string;
+    config?: string;
+  };
 }
 
-type Loader = (url: string) => Promise<State>;
+export type EditorMode = 'code' | 'config';
+
+export type Loader = (url: string) => Promise<State>;
+export type Optional<T, K extends keyof T> = Pick<Partial<T>, K> & Omit<T, K>;

src/lib/util/env.ts

@@ -1,4 +1,9 @@
-export const rendererUrl: string =
-	(import.meta.env.MERMAID_RENDERER_URL as string) ?? 'https://mermaid.ink';
-export const krokiRendererUrl: string =
-	(import.meta.env.MERMAID_KROKI_RENDERER_URL as string) ?? 'https://kroki.io';
+export const env = {
+  rendererUrl: import.meta.env.MERMAID_RENDERER_URL ?? 'https://mermaid.ink',
+  krokiRendererUrl: import.meta.env.MERMAID_KROKI_RENDERER_URL ?? 'https://kroki.io',
+  mermaidCDNUrl: import.meta.env.MERMAID_CDN_URL ?? 'https://unpkg.com/@mermaid-js',
+  mermaidBaseURL: import.meta.env.MERMAID_BASE_URL ?? 'http://localhost:9000',
+  useLocalMermaid: import.meta.env.MERMAID_LOCAL ?? false,
+  isDev: import.meta.env.DEV,
+  baseURL: import.meta.env.BASE_URL
+};

src/lib/util/error.ts

@@ -1,3 +0,0 @@
-import { writable } from 'svelte/store';
-
-export const errorStore = writable(undefined);

src/lib/util/fileLoaders/gist.ts

@@ -1,105 +1,107 @@
+/* eslint-disable @typescript-eslint/no-unsafe-return */
 /* eslint-disable @typescript-eslint/no-unsafe-assignment */
 /* eslint-disable @typescript-eslint/no-unsafe-member-access */
 /* eslint-disable @typescript-eslint/no-explicit-any */
 import type { State } from '$lib/types';
 import { defaultState } from '../state';
-import { addHistoryEntry } from '../../components/history/history';
+import { addHistoryEntry } from '../../components/History/history';
 
 const codeFileName = 'code.mmd';
 const configFileName = 'config.json';
 
 const isValidGist = (files: any): boolean => {
-	return codeFileName in files;
+  return codeFileName in files;
 };
 
 const getFileContent = async (file: any): Promise<string> => {
-	if (file.truncated) {
-		return await (await fetch(file.raw_url)).text();
-	}
-	return file.content;
+  if (file.truncated) {
+    return await (await fetch(file.raw_url)).text();
+  }
+  return file.content;
 };
 
 interface GistData {
-	code: string;
-	config?: string;
-	author: string;
-	time: number;
-	version: string;
-	url: string;
+  code: string;
+  config?: string;
+  author: string;
+  time: number;
+  version: string;
+  url: string;
 }
 
 const getGistData = async (gistURL: string): Promise<GistData> => {
-	// eslint-disable-next-line @typescript-eslint/no-unused-vars
-	const [_, __, gistID, revisionID] = gistURL.split('github.com').pop().split('/');
-	// eslint-disable-next-line @typescript-eslint/no-unsafe-assignment
-	const { html_url, files, history } = await (
-		await fetch(`https://api.github.com/gists/${gistID}${revisionID ? '/' + revisionID : ''}`)
-	).json();
-	if (isValidGist(files)) {
-		const code = await getFileContent(files[codeFileName]);
-		let config: string;
-		if (configFileName in files) {
-			config = await getFileContent(files[configFileName]);
-		}
-		const currentItem = history[0];
-		return {
-			url: `${html_url}/${currentItem.version}`,
-			code,
-			config,
-			author: currentItem.user.login,
-			time: new Date(currentItem.committed_at).getTime(),
-			version: (currentItem.version as string).slice(-7)
-		};
-	} else {
-		throw 'Invalid gist provided';
-	}
+  // eslint-disable-next-line @typescript-eslint/no-unused-vars
+  const [_, __, gistID, revisionID] = gistURL.split('github.com').pop().split('/');
+  // eslint-disable-next-line @typescript-eslint/no-unsafe-assignment
+  const { html_url, files, history } = await (
+    await fetch(`https://api.github.com/gists/${gistID}${revisionID ? '/' + revisionID : ''}`)
+  ).json();
+  if (isValidGist(files)) {
+    const code = await getFileContent(files[codeFileName]);
+    let config: string;
+    if (configFileName in files) {
+      config = await getFileContent(files[configFileName]);
+    }
+    const currentItem = history[0];
+    return {
+      // eslint-disable-next-line @typescript-eslint/restrict-template-expressions
+      url: `${html_url}/${currentItem.version}`,
+      code,
+      config,
+      author: currentItem.user.login,
+      time: new Date(currentItem.committed_at).getTime(),
+      version: (currentItem.version as string).slice(-7)
+    };
+  } else {
+    throw 'Invalid gist provided';
+  }
 };
 
 const getStateFromGist = (gist: GistData, gistURL: string = gist.url): State => {
-	const state: State = {
-		...defaultState,
-		code: gist.code,
-		loader: {
-			type: 'gist',
-			config: {
-				url: gistURL
-			}
-		}
-	};
-	gist.config && (state.mermaid = gist.config);
-	return state;
+  const state: State = {
+    ...defaultState,
+    code: gist.code,
+    loader: {
+      type: 'gist',
+      config: {
+        url: gistURL
+      }
+    }
+  };
+  gist.config && (state.mermaid = gist.config);
+  return state;
 };
 
 export const loadGistData = async (gistURL: string): Promise<State> => {
-	try {
-		// eslint-disable-next-line @typescript-eslint/no-unused-vars
-		const [_, __, gistID, revisionID] = gistURL.split('github.com').pop().split('/');
-		// eslint-disable-next-line @typescript-eslint/no-unsafe-assignment
-		const { history } = await (
-			await fetch(`https://api.github.com/gists/${gistID}${revisionID ? '/' + revisionID : ''}`)
-		).json();
-		const gistHistory: GistData[] = [];
-		for (const entry of history) {
-			// eslint-disable-next-line @typescript-eslint/no-unsafe-assignment
-			const data: GistData = await getGistData(entry.url).catch(() => undefined);
-			data && gistHistory.push(data);
-		}
-		if (gistHistory.length === 0) {
-			throw 'Invalid gist provided';
-		}
-		gistHistory.reverse();
-		const state = getStateFromGist(gistHistory.slice(-1).pop(), gistURL);
-		for (const gist of gistHistory) {
-			addHistoryEntry({
-				state: getStateFromGist(gist),
-				time: gist.time,
-				type: 'loader',
-				url: gist.url,
-				name: `${gist.author} v${gist.version}`
-			});
-		}
-		return state;
-	} catch (err) {
-		console.error(err);
-	}
+  try {
+    // eslint-disable-next-line @typescript-eslint/no-unused-vars
+    const [_, __, gistID, revisionID] = gistURL.split('github.com').pop().split('/');
+    // eslint-disable-next-line @typescript-eslint/no-unsafe-assignment
+    const { history } = await (
+      await fetch(`https://api.github.com/gists/${gistID}${revisionID ? '/' + revisionID : ''}`)
+    ).json();
+    const gistHistory: GistData[] = [];
+    for (const entry of history) {
+      // eslint-disable-next-line @typescript-eslint/no-unsafe-assignment
+      const data: GistData = await getGistData(entry.url).catch(() => undefined);
+      data && gistHistory.push(data);
+    }
+    if (gistHistory.length === 0) {
+      throw 'Invalid gist provided';
+    }
+    gistHistory.reverse();
+    const state = getStateFromGist(gistHistory.slice(-1).pop(), gistURL);
+    for (const gist of gistHistory) {
+      addHistoryEntry({
+        state: getStateFromGist(gist),
+        time: gist.time,
+        type: 'loader',
+        url: gist.url,
+        name: `${gist.author} v${gist.version}`
+      });
+    }
+    return state;
+  } catch (err) {
+    console.error(err);
+  }
 };

src/lib/util/fileLoaders/loader.ts

@@ -2,57 +2,58 @@ import { loadGistData } from './gist';
 import { updateCodeStore, defaultState } from '../state';
 import type { Loader, State } from '$lib/types';
 const loaders: Record<string, Loader> = {
-	gist: loadGistData
+  gist: loadGistData
 };
 
 export const loadDataFromUrl = async (): Promise<void> => {
-	const searchParams = new URLSearchParams(window.location.search);
-	let state: State = defaultState;
-	let code: string, config: string;
-	let loaded = false;
-	const codeURL: string = searchParams.get('code');
-	const configURL: string = searchParams.get('config');
+  const searchParams = new URLSearchParams(window.location.search);
+  let state: Partial<State> = defaultState;
+  let code: string, config: string;
+  let loaded = false;
+  const codeURL: string = searchParams.get('code');
+  const configURL: string = searchParams.get('config');
 
-	if (codeURL) {
-		code = await (await fetch(codeURL)).text();
-		loaded = true;
-	}
-	if (configURL) {
-		config = await (await fetch(configURL)).text();
-	} else {
-		config = defaultState.mermaid;
-	}
-	if (!code) {
-		for (const [key, value] of searchParams.entries()) {
-			if (key in loaders) {
-				try {
-					state = await loaders[key](value);
-					loaded = true;
-					break;
-				} catch (err) {
-					console.error(err);
-				}
-			}
-		}
-	} else {
-		state = {
-			code,
-			mermaid: config,
-			loader: {
-				type: 'files',
-				config: {
-					codeURL,
-					configURL
-				}
-			}
-		} as State;
-	}
-	loaded &&
-		updateCodeStore({
-			...state,
-			autoSync: true,
-			updateDiagram: true,
-			updateEditor: true
-		});
-	// window.location.search = '';
+  if (codeURL) {
+    code = await (await fetch(codeURL)).text();
+    loaded = true;
+  }
+  if (configURL) {
+    config = await (await fetch(configURL)).text();
+  } else {
+    config = defaultState.mermaid;
+  }
+  if (!code) {
+    // eslint-disable-next-line @typescript-eslint/ban-ts-comment
+    // @ts-ignore
+    // eslint-disable-next-line @typescript-eslint/no-unsafe-call
+    for (const [key, value] of searchParams.entries()) {
+      if (key in loaders) {
+        try {
+          state = await loaders[key](value);
+          loaded = true;
+          break;
+        } catch (err) {
+          console.error(err);
+        }
+      }
+    }
+  } else {
+    state = {
+      code,
+      mermaid: config,
+      loader: {
+        type: 'files',
+        config: {
+          codeURL,
+          configURL
+        }
+      }
+    };
+  }
+  loaded &&
+    updateCodeStore({
+      ...state,
+      autoSync: true,
+      updateDiagram: true
+    });
 };

src/lib/util/loading.ts

@@ -3,18 +3,18 @@ import type { Writable } from 'svelte/store';
 import type { LoadingState } from '$lib/types';
 
 const defaultLoading: LoadingState = {
-	loading: false
+  loading: false
 };
 
 export const loadingStateStore: Writable<LoadingState> = writable(defaultLoading);
 export const initLoading = async <T>(message: string, task: Promise<T>): Promise<T> => {
-	loadingStateStore.set({
-		loading: true,
-		message
-	});
-	const result: T = await task;
-	loadingStateStore.set({
-		loading: false
-	});
-	return result;
+  loadingStateStore.set({
+    loading: true,
+    message
+  });
+  const result: T = await task;
+  loadingStateStore.set({
+    loading: false
+  });
+  return result;
 };

src/lib/util/mermaid.ts

@@ -0,0 +1,24 @@
+import mermaid, { type MermaidConfig } from 'mermaid';
+import mindmap from '@mermaid-js/mermaid-mindmap';
+
+const initialize = mermaid.registerExternalDiagrams([mindmap]);
+
+export const init = async () => {
+  await initialize;
+};
+
+export const render = async (
+  config: MermaidConfig,
+  code: string,
+  id: string,
+  callback: Parameters<typeof mermaid.render>[2]
+): Promise<void> => {
+  await init();
+  mermaid.initialize(config);
+  await mermaid.mermaidAPI.renderAsync(id, code, callback);
+};
+
+export const parse = async (code: string): Promise<boolean> => {
+  await init();
+  return (await mermaid.parseAsync(code)) as boolean;
+};

src/lib/util/migrations.test.ts

@@ -0,0 +1,34 @@
+import type { HistoryEntry } from '$lib/types';
+import { describe, it, expect, beforeEach } from 'vitest';
+
+describe('migrations', () => {
+  beforeEach(() => {
+    window.localStorage.setItem(
+      'manualHistoryStore',
+      '[{"state":{"code":"graph TD\\n    A[Halloween] -->|Get money| B(Go shopping)","mermaid":"{\\n  \\"theme\\": \\"dark\\"\\n}","autoSync":true,"updateDiagram":false},"time":0,"type":"manual","name":"hollow-art"},{"state":{"code":"graph TD\\n    A[Christmas] -->|Get money| B(Go shopping)","mermaid":"{\\n  \\"theme\\": \\"dark\\"\\n}","autoSync":true,"updateDiagram":true},"time":0,"type":"manual","name":"helpful-ocean"}]'
+    );
+    window.localStorage.setItem(
+      'autoHistoryStore',
+      '[{"state":{"code":"graph TD\\n    A[New Year] -->|Get money| B(Go shopping)","mermaid":"{\\n  \\"theme\\": \\"dark\\"\\n}","autoSync":true,"updateDiagram":false},"time":0,"type":"auto","name":"barking-dog"},{"state":{"code":"graph TD\\n    A[Christmas] -->|Get money| B(Go shopping)","mermaid":"{\\n  \\"theme\\": \\"dark\\"\\n}","autoSync":true,"updateDiagram":true},"time":0,"type":"manual","name":"needy-mosquito"}]'
+    );
+  });
+
+  it('should migrate from v0 to v1', async () => {
+    const { applyMigrations } = await import('./migrations');
+    let manualHistoryStore: HistoryEntry[] = JSON.parse(
+      window.localStorage.getItem('manualHistoryStore')
+    );
+    let autoHistoryStore: HistoryEntry[] = JSON.parse(
+      window.localStorage.getItem('autoHistoryStore')
+    );
+    expect(manualHistoryStore.every(({ id }) => id !== undefined)).toBe(false);
+    expect(autoHistoryStore.every(({ id }) => id !== undefined)).toBe(false);
+
+    applyMigrations();
+
+    manualHistoryStore = JSON.parse(window.localStorage.getItem('manualHistoryStore'));
+    autoHistoryStore = JSON.parse(window.localStorage.getItem('autoHistoryStore'));
+    expect(manualHistoryStore.every(({ id }) => id !== undefined)).toBe(true);
+    expect(autoHistoryStore.every(({ id }) => id !== undefined)).toBe(true);
+  });
+});

src/lib/util/migrations.ts

@@ -0,0 +1,35 @@
+import { writable, get, type Writable } from 'svelte/store';
+import { persist, localStorage } from '$lib/util/persist';
+import { injectHistoryIDs } from '$lib/components/History/history';
+import { logEvent } from './stats';
+
+interface MigrationState {
+  version: number;
+}
+
+const migrations: { [key: string]: () => void } = {
+  injectHistoryIDs
+};
+
+const migrationStore: Writable<MigrationState> = persist(
+  writable({ version: -1 }),
+  localStorage(),
+  'migrations'
+);
+
+export const applyMigrations = (): void => {
+  const { version }: MigrationState = get(migrationStore);
+  const allMigrations = Object.entries(migrations);
+  if (version === allMigrations.length - 1) {
+    return;
+  }
+  console.log(`Current migration version: v${version}. Migrating to v${allMigrations.length - 1}.`);
+  for (let i = version + 1; i < allMigrations.length; i++) {
+    const [key, fn] = allMigrations[i];
+    console.log(`Applying migration ${i}: ${key}.`);
+    fn();
+    logEvent('migration', { key });
+    migrationStore.set({ version: i });
+  }
+  logEvent('migration', { status: 'complete', from: version, to: allMigrations.length - 1 });
+};

src/lib/util/notify.ts

@@ -1,7 +1,7 @@
 export const notify = (message: string): void => {
-	alert(message);
+  alert(message);
 };
 
 export const prompt = (message: string): boolean => {
-	return confirm(message);
+  return confirm(message);
 };

src/lib/util/persist.ts

@@ -0,0 +1,265 @@
+/* eslint-disable @typescript-eslint/no-explicit-any */
+// Copied from https://github.com/MacFJA/svelte-persistent-store
+// # The MIT License (MIT)
+
+// Copyright (c) 2021 [MacFJA](https://github.com/MacFJA)
+
+// > Permission is hereby granted, free of charge, to any person obtaining a copy
+// > of this software and associated documentation files (the "Software"), to deal
+// > in the Software without restriction, including without limitation the rights
+// > to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// > copies of the Software, and to permit persons to whom the Software is
+// > furnished to do so, subject to the following conditions:
+// >
+// > The above copyright notice and this permission notice shall be included in
+// > all copies or substantial portions of the Software.
+// >
+// > THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// > IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// > FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// > AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// > LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// > OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// > THE SOFTWARE.
+
+import ESSerializer from 'esserializer';
+import type { Writable } from 'svelte/store';
+
+/**
+ * Disabled warnings about missing/unavailable storages
+ */
+export function disableWarnings(): void {
+  noWarnings = true;
+}
+/**
+ * If set to true, no warning will be emitted if the requested Storage is not found.
+ * This option can be useful when the lib is used on a server.
+ */
+let noWarnings = false;
+/**
+ * List of storages where the warning have already been displayed.
+ */
+const alreadyWarnFor: Array<string> = [];
+
+/**
+ * Add a log to indicate that the requested Storage have not been found.
+ * @param {string} storageName
+ */
+const warnStorageNotFound = (storageName) => {
+  const isProduction = typeof process !== 'undefined' && process.env?.NODE_ENV === 'production';
+
+  if (!noWarnings && alreadyWarnFor.indexOf(storageName) === -1 && !isProduction) {
+    let message = `Unable to find the ${storageName}. No data will be persisted.`;
+    if (typeof window === 'undefined') {
+      message +=
+        '\n' +
+        'Are you running on a server? Most of storages are not available while running on a server.';
+    }
+    console.warn(message);
+    alreadyWarnFor.push(storageName);
+  }
+};
+
+const allowedClasses = [];
+/**
+ * Add a class to the allowed list of classes to be serialized
+ * @param classDef The class to add to the list
+ */
+export const addSerializableClass = (classDef: () => unknown): void => {
+  allowedClasses.push(classDef);
+};
+
+const serialize = (value: unknown): string => ESSerializer.serialize(value);
+const deserialize = (value: string): unknown => {
+  // @TODO: to remove in the next major
+  if (value === 'undefined') {
+    return undefined;
+  }
+
+  if (value !== null && value !== undefined) {
+    try {
+      return ESSerializer.deserialize(value, allowedClasses);
+    } catch (e) {
+      // Do nothing
+      // use the value "as is"
+    }
+    try {
+      return JSON.parse(value);
+    } catch (e) {
+      // Do nothing
+      // use the value "as is"
+    }
+  }
+  return value;
+};
+
+/**
+ * A store that keep it's value in time.
+ */
+export interface PersistentStore<T> extends Writable<T> {
+  /**
+   * Delete the store value from the persistent storage
+   */
+  delete(): void;
+}
+
+/**
+ * Storage interface
+ */
+export interface StorageInterface<T> {
+  /**
+   * Get a value from the storage.
+   *
+   * If the value doesn't exists in the storage, `null` should be returned.
+   * This method MUST be synchronous.
+   * @param key The key/name of the value to retrieve
+   */
+  getValue(key: string): T | null;
+
+  /**
+   * Save a value in the storage.
+   * @param key The key/name of the value to save
+   * @param value The value to save
+   */
+  setValue(key: string, value: T): void;
+
+  /**
+   * Remove a value from the storage
+   * @param key The key/name of the value to remove
+   */
+  deleteValue(key: string): void;
+}
+
+export interface SelfUpdateStorageInterface<T> extends StorageInterface<T> {
+  /**
+   * Add a listener to the storage values changes
+   * @param {string} key The key to listen
+   * @param {(newValue: T) => void} listener The listener callback function
+   */
+  addListener(key: string, listener: (newValue: T) => void): void;
+  /**
+   * Remove a listener from the storage values changes
+   * @param {string} key The key that was listened
+   * @param {(newValue: T) => void} listener The listener callback function to remove
+   */
+  removeListener(key: string, listener: (newValue: T) => void): void;
+}
+
+/**
+ * Make a store persistent
+ * @param {Writable<*>} store The store to enhance
+ * @param {StorageInterface} storage The storage to use
+ * @param {string} key The name of the data key
+ */
+export function persist<T>(
+  store: Writable<T>,
+  storage: StorageInterface<T>,
+  key: string
+): PersistentStore<T> {
+  const initialValue = storage.getValue(key);
+
+  if (null !== initialValue) {
+    store.set(initialValue);
+  }
+
+  if ((storage as SelfUpdateStorageInterface<T>).addListener) {
+    (storage as SelfUpdateStorageInterface<T>).addListener(key, (newValue) => {
+      store.set(newValue);
+    });
+  }
+
+  store.subscribe((value) => {
+    storage.setValue(key, value);
+  });
+
+  return {
+    ...store,
+    delete() {
+      storage.deleteValue(key);
+    }
+  };
+}
+
+function getBrowserStorage(
+  browserStorage: Storage,
+  listenExternalChanges = false
+): SelfUpdateStorageInterface<any> {
+  const listeners: Array<{ key: string; listener: (newValue: any) => void }> = [];
+  const listenerFunction = (event: StorageEvent) => {
+    const eventKey = event.key;
+    if (event.storageArea === browserStorage) {
+      listeners
+        .filter(({ key }) => key === eventKey)
+        .forEach(({ listener }) => {
+          listener(deserialize(event.newValue));
+        });
+    }
+  };
+  const connect = () => {
+    if (listenExternalChanges && typeof window !== 'undefined' && window?.addEventListener) {
+      window.addEventListener('storage', listenerFunction);
+    }
+  };
+  const disconnect = () => {
+    if (listenExternalChanges && typeof window !== 'undefined' && window?.removeEventListener) {
+      window.removeEventListener('storage', listenerFunction);
+    }
+  };
+
+  return {
+    addListener(key: string, listener: (newValue: any) => void) {
+      listeners.push({ key, listener });
+      if (listeners.length === 1) {
+        connect();
+      }
+    },
+    removeListener(key: string, listener: (newValue: any) => void) {
+      const index = listeners.indexOf({ key, listener });
+      if (index !== -1) {
+        listeners.splice(index, 1);
+      }
+      if (listeners.length === 0) {
+        disconnect();
+      }
+    },
+    getValue(key: string): any | null {
+      const value = browserStorage.getItem(key);
+      return deserialize(value);
+    },
+    deleteValue(key: string) {
+      browserStorage.removeItem(key);
+    },
+    setValue(key: string, value: any) {
+      browserStorage.setItem(key, serialize(value));
+    }
+  };
+}
+
+/**
+ * Storage implementation that use the browser local storage
+ * @param {boolean} listenExternalChanges - Update the store if the localStorage is updated from another page
+ */
+export function localStorage<T>(listenExternalChanges = false): StorageInterface<T> {
+  if (typeof window !== 'undefined' && window?.localStorage) {
+    return getBrowserStorage(window.localStorage, listenExternalChanges);
+  }
+  warnStorageNotFound('window.localStorage');
+  return noopStorage();
+}
+
+/**
+ * Storage implementation that do nothing
+ */
+export function noopStorage(): StorageInterface<any> {
+  return {
+    getValue(): null {
+      return null;
+    },
+    deleteValue() {
+      // Do nothing
+    },
+    setValue() {
+      // Do nothing
+    }
+  };
+}

src/lib/util/serde.test.ts

@@ -0,0 +1,40 @@
+import { describe, expect, it } from 'vitest';
+import { serializeState, deserializeState, type SerdeType } from './serde';
+import { defaultState } from './state';
+import type { State } from '$lib/types';
+
+describe('Serde tests', () => {
+  const verifySerde = (state: State, serde?: SerdeType): string => {
+    const serialized = serializeState(state, serde);
+    const deserialized = deserializeState(serialized);
+    expect(deserialized).to.deep.equal(state);
+    return serialized;
+  };
+
+  it('should serialize and deserialize with default serde', () => {
+    expect(verifySerde(defaultState)).toMatchInlineSnapshot(
+      '"pako:eNpVj81qw0AMhF9F6NRC_AI-BGK7zSXQQHLz5iBsObuk-8Naphjb7551fEl1EjPfiNGEjW8Zc7xHChqulXKQ5lCXOppeLPU3yLL9fGQB6x2PMxQfRw-99iEYd__c-GKFoJxOK8Yg2rjHslnlK__jeIaqPlEQH27vzvXPz_BVm7NO5_87OnJKfdcd5R1lDUUoKb4Q3KHlaMm0qfq0KgpFs2WFeVpb7mj4FYXKLQmlQfxldA3mEgfe4RBaEq4MpaftJi5PNtJU8w"'
+    );
+  });
+
+  it('should serialize and deserialize with base64 serde', () => {
+    expect(verifySerde(defaultState, 'base64')).toMatchInlineSnapshot(
+      '"base64:eyJjb2RlIjoiZ3JhcGggVERcbiAgICBBW0NocmlzdG1hc10gLS0-fEdldCBtb25leXwgQihHbyBzaG9wcGluZylcbiAgICBCIC0tPiBDe0xldCBtZSB0aGlua31cbiAgICBDIC0tPnxPbmV8IERbTGFwdG9wXVxuICAgIEMgLS0-fFR3b3wgRVtpUGhvbmVdXG4gICAgQyAtLT58VGhyZWV8IEZbZmE6ZmEtY2FyIENhcl1cbiAgIiwibWVybWFpZCI6IntcbiAgXCJ0aGVtZVwiOiBcImRlZmF1bHRcIlxufSIsImF1dG9TeW5jIjp0cnVlLCJ1cGRhdGVEaWFncmFtIjp0cnVlfQ"'
+    );
+  });
+
+  it('should serialize and deserialize with pako serde', () => {
+    expect(verifySerde(defaultState, 'pako')).toMatchInlineSnapshot(
+      '"pako:eNpVj81qw0AMhF9F6NRC_AI-BGK7zSXQQHLz5iBsObuk-8Naphjb7551fEl1EjPfiNGEjW8Zc7xHChqulXKQ5lCXOppeLPU3yLL9fGQB6x2PMxQfRw-99iEYd__c-GKFoJxOK8Yg2rjHslnlK__jeIaqPlEQH27vzvXPz_BVm7NO5_87OnJKfdcd5R1lDUUoKb4Q3KHlaMm0qfq0KgpFs2WFeVpb7mj4FYXKLQmlQfxldA3mEgfe4RBaEq4MpaftJi5PNtJU8w"'
+    );
+  });
+
+  it('should throw error for unrecognized serde', () => {
+    // eslint-disable-next-line @typescript-eslint/ban-ts-comment
+    // @ts-expect-error
+    expect(() => serializeState(defaultState, 'unknown')).toThrowError(
+      'Unknown serde type: unknown'
+    );
+    expect(() => deserializeState('unknown:hello')).toThrowError('Unknown serde type: unknown');
+  });
+});

src/lib/util/serde.ts

@@ -3,59 +3,61 @@ import { toUint8Array, fromUint8Array, toBase64, fromBase64 } from 'js-base64';
 import type { State } from '$lib/types';
 
 interface Serde {
-	serialize: (state: string) => string;
-	deserialize: (state: string) => string;
+  serialize: (state: string) => string;
+  deserialize: (state: string) => string;
 }
 
 const base64Serde: Serde = {
-	serialize: (state: string): string => {
-		return toBase64(state, true);
-	},
-	deserialize: (state: string): string => {
-		return fromBase64(state);
-	}
+  serialize: (state: string): string => {
+    return toBase64(state, true);
+  },
+  deserialize: (state: string): string => {
+    return fromBase64(state);
+  }
 };
 
 export const pakoSerde: Serde = {
-	serialize: (state: string): string => {
-		const data = new TextEncoder().encode(state);
-		const compressed = deflate(data, { level: 9 });
-		return fromUint8Array(compressed, true);
-	},
-	deserialize: (state: string): string => {
-		const data = toUint8Array(state);
-		return inflate(data, { to: 'string' });
-	}
+  serialize: (state: string): string => {
+    const data = new TextEncoder().encode(state);
+    const compressed = deflate(data, { level: 9 });
+    return fromUint8Array(compressed, true);
+  },
+  deserialize: (state: string): string => {
+    const data = toUint8Array(state);
+    return inflate(data, { to: 'string' });
+  }
 };
 
-const serdes: { [key: string]: Serde } = {
-	base64: base64Serde,
-	pako: pakoSerde
+export type SerdeType = 'base64' | 'pako';
+
+const serdes: { [key in SerdeType]: Serde } = {
+  base64: base64Serde,
+  pako: pakoSerde
 };
 
-type SerdeType = keyof typeof serdes;
-
-export const serializeState = (state: State): string => {
-	const json = JSON.stringify(state);
-	const defaultSerde: SerdeType = 'pako';
-	const serialized = serdes[defaultSerde].serialize(json);
-	return `${defaultSerde}:${serialized}`;
+export const serializeState = (state: State, serde: SerdeType = 'pako'): string => {
+  if (serdes[serde] === undefined) {
+    throw new Error(`Unknown serde type: ${serde}`);
+  }
+  const json = JSON.stringify(state);
+  const serialized = serdes[serde].serialize(json);
+  return `${serde}:${serialized}`;
 };
 
 export const deserializeState = (state: string): State => {
-	let type: SerdeType, serialized: string;
-	if (state.includes(':')) {
-		let tempType: string;
-		[tempType, serialized] = state.split(':');
-		if (tempType in serdes) {
-			type = tempType;
-		} else {
-			throw new Error(`Unknown serde type: ${tempType}`);
-		}
-	} else {
-		type = 'base64';
-		serialized = state;
-	}
-	const json = serdes[type].deserialize(serialized);
-	return JSON.parse(json) as State;
+  let type: SerdeType, serialized: string;
+  if (state.includes(':')) {
+    let tempType: string;
+    [tempType, serialized] = state.split(':');
+    if (tempType in serdes) {
+      type = tempType as SerdeType;
+    } else {
+      throw new Error(`Unknown serde type: ${tempType}`);
+    }
+  } else {
+    type = 'base64';
+    serialized = state;
+  }
+  const json = serdes[type].deserialize(serialized);
+  return JSON.parse(json) as State;
 };

src/lib/util/state.ts

@@ -1,28 +1,28 @@
-import { writable, get, derived } from 'svelte/store';
-import type { Readable } from 'svelte/store';
-import { persist, localStorage } from '@macfja/svelte-persistent-store';
-import type { State } from '$lib/types';
-import { saveStatistics } from './stats';
+import { writable, get, type Readable, derived } from 'svelte/store';
+import { persist, localStorage } from './persist';
+import { saveStatistics, countLines } from './stats';
 import { serializeState, deserializeState } from './serde';
+import { cmdKey, errorDebug, AsyncQueue } from './util';
+import { parse } from './mermaid';
 
+import type { MarkerData, State, ValidatedState } from '$lib/types';
 export const defaultState: State = {
-	code: `graph TD
+  code: `graph TD
     A[Christmas] -->|Get money| B(Go shopping)
     B --> C{Let me think}
     C -->|One| D[Laptop]
     C -->|Two| E[iPhone]
     C -->|Three| F[fa:fa-car Car]
   `,
-	mermaid: JSON.stringify(
-		{
-			theme: 'default'
-		},
-		null,
-		2
-	),
-	updateEditor: false,
-	autoSync: true,
-	updateDiagram: true
+  mermaid: JSON.stringify(
+    {
+      theme: 'default'
+    },
+    null,
+    2
+  ),
+  autoSync: true,
+  updateDiagram: true
 };
 
 const urlParseFailedState = `graph TD
@@ -36,90 +36,169 @@ const urlParseFailedState = `graph TD
     G --> |"No :("| H(Try using the Timeline tab in History <br/>from same browser you used to create the diagram.)
     click D href "https://github.com/mermaid-js/mermaid-live-editor/issues/new?assignees=&labels=bug&template=bug_report.md&title=Broken%20link" "Raise issue"`;
 
-export const codeStore = persist(writable(defaultState), localStorage(), 'codeStore');
-export const serializedState: Readable<string> = derived([codeStore], ([code], set) => {
-	set(serializeState(code));
-});
+// inputStateStore handles all updates and is shared externally when exporting via URL, History, etc.
+export const inputStateStore = persist(writable(defaultState), localStorage(), 'codeStore');
 
-export const loadState = (data: string): void => {
-	let state: State;
-	console.log('Loading', data);
-	try {
-		state = deserializeState(data);
-		const mermaidConfig: { [key: string]: string } =
-			typeof state.mermaid === 'string' ? JSON.parse(state.mermaid) : state.mermaid;
-		if (
-			mermaidConfig.securityLevel &&
-			mermaidConfig.securityLevel !== 'strict' &&
-			confirm(
-				`Removing "securityLevel":"${mermaidConfig.securityLevel}" from the config for safety.\nClick Cancel if you trust the source of this Diagram.`
-			)
-		) {
-			delete mermaidConfig.securityLevel; // Prevent setting overriding securityLevel when loading state to mitigate possible XSS attack
-		}
+export const currentState: ValidatedState = (() => {
+  const state = get(inputStateStore);
+  return {
+    ...state,
+    serialized: serializeState(state),
+    errorMarkers: [],
+    error: undefined,
+    editorMode: state.editorMode ?? 'code'
+  };
+})();
 
-		state.mermaid = JSON.stringify(mermaidConfig, null, 2);
-	} catch (e) {
-		state = get(codeStore);
-		if (data) {
-			console.error('Init error', e);
-			state.code = urlParseFailedState;
-		}
-	}
-	updateCodeStore({ ...state, updateEditor: true });
+let q: AsyncQueue<State>;
+
+const processState = async (state: State) => {
+  const processed: ValidatedState = {
+    ...state,
+    serialized: '',
+    errorMarkers: [],
+    error: undefined,
+    editorMode: state.editorMode ?? 'code'
+  };
+  // No changes should be done to fields part of `state`.
+  try {
+    processed.serialized = serializeState(state);
+    await parse(state.code);
+    JSON.parse(state.mermaid);
+  } catch (e) {
+    processed.error = e;
+    errorDebug();
+    console.error(e);
+    if (e.hash) {
+      try {
+        const marker: MarkerData = {
+          severity: 8, // Error
+          startLineNumber: e.hash.loc.first_line,
+          startColumn: e.hash.loc.first_column,
+          endLineNumber: e.hash.loc.last_line,
+          endColumn: (e.hash.loc.last_column as number) + 1,
+          message: e.str
+        };
+        processed.errorMarkers = [marker];
+      } catch (err) {
+        console.error('Error without line helper', err);
+      }
+    }
+  }
+  return processed;
 };
 
-export const updateCodeStore = (newState: State): void => {
-	codeStore.update((state) => {
-		return { ...state, ...newState };
-	});
+// All internal reads should be done via stateStore, but it should not be persisted/shared externally.
+export const stateStore: Readable<ValidatedState> = derived(
+  [inputStateStore],
+  ([state], set) => {
+    if (!q) {
+      // Initialize the queue for first time.
+      q = new AsyncQueue(async (state: State) => {
+        const newState = await processState(state);
+        set(newState);
+      });
+    }
+    q.process(state);
+  },
+  currentState
+);
+
+export const loadState = (data: string): void => {
+  let state: State;
+  console.log(`Loading '${data}'`);
+  try {
+    state = deserializeState(data);
+    const mermaidConfig: { [key: string]: string } =
+      typeof state.mermaid === 'string' ? JSON.parse(state.mermaid) : state.mermaid;
+    if (
+      mermaidConfig.securityLevel &&
+      mermaidConfig.securityLevel !== 'strict' &&
+      confirm(
+        `Removing "securityLevel":"${mermaidConfig.securityLevel}" from the config for safety.\nClick Cancel if you trust the source of this Diagram.`
+      )
+    ) {
+      delete mermaidConfig.securityLevel; // Prevent setting overriding securityLevel when loading state to mitigate possible XSS attack
+    }
+    state.mermaid = JSON.stringify(mermaidConfig, null, 2);
+  } catch (e) {
+    state = get(inputStateStore);
+    if (data) {
+      console.error('Init error', e);
+      state.code = urlParseFailedState;
+      state.mermaid = defaultState.mermaid;
+    }
+  }
+  updateCodeStore(state);
+};
+
+export const updateCodeStore = (newState: Partial<State>): void => {
+  inputStateStore.update((state) => {
+    return { ...state, ...newState };
+  });
 };
 
 let prompted = false;
-export const updateCode = (code: string, updateEditor: boolean, updateDiagram = false): void => {
-	saveStatistics(code);
-	const lines = (code.match(/\n/g) || '').length + 1;
+export const updateCode = (
+  code: string,
+  {
+    updateDiagram = false,
+    resetPanZoom = false
+  }: { updateDiagram?: boolean; resetPanZoom?: boolean } = {}
+): void => {
+  console.log('updateCode', code);
+  const lines = countLines(code);
+  saveStatistics(code);
+  errorDebug();
+  if (lines > 50 && !prompted && get(stateStore).autoSync) {
+    const turnOff = confirm(
+      `Long diagram detected. Turn off Auto Sync? Use ${cmdKey} + Enter or click the sync logo to manually sync.`
+    );
+    prompted = true;
+    if (turnOff) {
+      updateCodeStore({
+        autoSync: false
+      });
+    }
+  }
 
-	if (lines > 50 && !prompted && get(codeStore).autoSync) {
-		const turnOff = confirm(
-			'Long diagram detected. Turn off Auto Sync? Click the sync logo to manually sync.'
-		);
-		prompted = true;
-		if (turnOff) {
-			updateCodeStore({
-				autoSync: false
-			} as State);
-		}
-	}
-
-	codeStore.update((state) => {
-		return { ...state, code, updateEditor, updateDiagram };
-	});
+  inputStateStore.update((state) => {
+    if (resetPanZoom) {
+      state.pan = undefined;
+      state.zoom = undefined;
+    }
+    return { ...state, code, updateDiagram };
+  });
 };
 
-export const updateConfig = (config: string, updateEditor: boolean): void => {
-	codeStore.update((state) => {
-		return { ...state, mermaid: config, updateEditor };
-	});
+export const updateConfig = (config: string): void => {
+  console.log('updateConfig', config);
+  inputStateStore.update((state) => {
+    return { ...state, mermaid: config };
+  });
 };
 
 export const toggleDarkTheme = (dark: boolean): void => {
-	codeStore.update((state) => {
-		const config = JSON.parse(state.mermaid);
-		if (!config.theme || ['dark', 'default'].includes(config.theme)) {
-			config.theme = dark ? 'dark' : 'default';
-		}
+  inputStateStore.update((state) => {
+    const config = JSON.parse(state.mermaid);
+    if (!config.theme || ['dark', 'default'].includes(config.theme)) {
+      config.theme = dark ? 'dark' : 'default';
+    }
 
-		return { ...state, mermaid: JSON.stringify(config, null, 2), updateEditor: true };
-	});
+    return { ...state, mermaid: JSON.stringify(config, null, 2) };
+  });
 };
 
+let urlDebounce: number;
 export const initURLSubscription = (): void => {
-	serializedState.subscribe((state: string) => {
-		history.replaceState(undefined, undefined, `#${state}`);
-	});
+  stateStore.subscribe(({ serialized }) => {
+    clearTimeout(urlDebounce);
+    urlDebounce = window.setTimeout(() => {
+      history.replaceState(undefined, undefined, `#${serialized}`);
+    }, 250);
+  });
 };
 
 export const getStateString = (): string => {
-	return JSON.stringify(get(codeStore));
+  return JSON.stringify(get(inputStateStore));
 };

src/lib/util/stats.test.ts

@@ -0,0 +1,19 @@
+import { describe, it, expect } from 'vitest';
+import { detectType } from './stats';
+describe('diagram detection', () => {
+  it('should detect diagrams correctly', () => {
+    expect(
+      detectType(`%%{{
+			graph`)
+    ).toBe('graph');
+    expect(detectType(`gitGraph`)).toBe('gitGraph');
+    expect(
+      detectType(`%%{{
+
+
+			flowChart
+			graph`)
+    ).toBe('flowChart');
+    expect(detectType(`loki -> thor`)).toBe(undefined);
+  });
+});

src/lib/util/stats.ts

@@ -1,49 +1,98 @@
-import { browser } from '$app/env';
+import { browser } from '$app/environment';
 import type { AnalyticsInstance } from 'analytics';
-
 export let analytics: AnalyticsInstance;
 
 export const initAnalytics = async (): Promise<void> => {
-	if (browser && !analytics) {
-		try {
-			const { Analytics } = await import('analytics');
-			// eslint-disable-next-line @typescript-eslint/no-unsafe-assignment
-			const googleAnalytics = await import('@analytics/google-analytics');
-			analytics = Analytics({
-				app: 'mermaid-live-editor',
-				// eslint-disable-next-line @typescript-eslint/no-unsafe-assignment
-				plugins: [
-					// eslint-disable-next-line @typescript-eslint/no-unsafe-call, @typescript-eslint/no-unsafe-member-access
-					googleAnalytics.init({
-						trackingId: 'UA-153180559-1'
-					})
-				]
-			});
-		} catch {
-			console.info('Analytics blocked ;)');
-		}
-	}
+  if (browser && !analytics) {
+    try {
+      const [{ Analytics }, { default: plausible }] = await Promise.all([
+        import('analytics'),
+        import('analytics-plugin-plausible')
+      ]);
+      analytics = Analytics({
+        app: 'mermaid-live-editor',
+        plugins: [
+          plausible({
+            domain: 'mermaid.live',
+            hashMode: false,
+            trackLocalhost: false, // By default 'false'
+            apiHost: 'https://plausible.io'
+          })
+        ]
+      });
+    } catch (e) {
+      console.log(e);
+      console.info('Analytics blocked ;)');
+    }
+  }
 };
 
-const detectType = (text: string): string => {
-	return text
-		.replace(/^\s*%%.*\n/g, '\n')
-		.trimStart()
-		.split(' ')[0];
+export const detectType = (text: string): string => {
+  const possibleDiagramTypes = [
+    'classDiagram',
+    'erDiagram',
+    'flowChart',
+    'gantt',
+    'gitGraph',
+    'graph',
+    'journey',
+    'pie',
+    'stateDiagram'
+  ];
+  const firstLine = text
+    .replace(/^\s*%%.*\n/g, '\n')
+    .trimStart()
+    .split(' ')[0]
+    .toLowerCase();
+  const detectedDiagram = possibleDiagramTypes.find((d) => firstLine.includes(d.toLowerCase()));
+  return detectedDiagram;
+};
+
+export const countLines = (code: string): number => {
+  return (code.match(/\n/g) || '').length + 1;
 };
 
-// manual debounce
-let timeout;
 export const saveStatistics = (graph: string): void => {
-	if (analytics) {
-		clearTimeout(timeout);
-		// Only save statistics after a 5 sec delay
-		timeout = setTimeout(function () {
-			const graphType = detectType(graph);
-			console.debug('ga:', 'send', 'event', 'render', graphType);
-			void analytics.track('render', {
-				graphType
-			});
-		}, 5000);
-	}
+  const graphType = detectType(graph);
+  if (!graphType) {
+    return;
+  }
+  const length = countLines(graph);
+  logEvent('render', { graphType, length });
+};
+
+const minutesToMilliSeconds = (minutes: number): number => {
+  return minutes * 60_000;
+};
+
+const defaultDelay = minutesToMilliSeconds(1);
+const delaysPerEvent = {
+  render: minutesToMilliSeconds(5),
+  panZoom: minutesToMilliSeconds(10),
+  copyClipboard: defaultDelay,
+  download: defaultDelay,
+  copyMarkdown: defaultDelay,
+  loadGist: defaultDelay,
+  loadSampleDiagram: defaultDelay,
+  renderDiagram: defaultDelay,
+  history: defaultDelay,
+  migration: defaultDelay,
+  themeChange: defaultDelay
+};
+export type AnalyticsEvent = keyof typeof delaysPerEvent;
+const timeouts: Record<string, number> = {};
+// manual debounce to reduce the number of events sent to analytics
+export const logEvent = (name: AnalyticsEvent, data?: unknown): void => {
+  if (!analytics) {
+    return;
+  }
+  const key = data ? JSON.stringify({ name, data }) : name;
+  if (timeouts[key] === undefined) {
+    void analytics.track(name, data);
+  } else {
+    clearTimeout(timeouts[key]);
+  }
+  timeouts[key] = window.setTimeout(() => {
+    delete timeouts[key];
+  }, delaysPerEvent[name]);
 };

src/lib/util/theme.ts

@@ -1,36 +1,38 @@
 import { writable } from 'svelte/store';
 import type { Writable } from 'svelte/store';
-import { persist, localStorage } from '@macfja/svelte-persistent-store';
+import { persist, localStorage } from '$lib/util/persist';
+import { logEvent } from './stats';
 
 export interface ThemeConfig {
-	isDark: boolean;
-	theme?: string;
+  isDark: boolean;
+  theme?: string;
 }
 
 export const themeStore: Writable<ThemeConfig> = persist(
-	writable({
-		isDark: false
-	}),
-	localStorage(),
-	'themeStore'
+  writable({
+    isDark: false
+  }),
+  localStorage(),
+  'themeStore'
 );
 
 const darkThemes = [
-	'dark',
-	'synthwave',
-	'halloween',
-	'aqua',
-	'forest',
-	'luxury',
-	'black',
-	'dracula'
+  'dark',
+  'synthwave',
+  'halloween',
+  'aqua',
+  'forest',
+  'luxury',
+  'black',
+  'dracula'
 ];
 
 export const setTheme = (theme: string): void => {
-	if (theme.includes(' ')) {
-		theme = theme.split(' ')[1].trim();
-	}
-	const isDark = darkThemes.includes(theme);
-	console.log('Setting theme', theme);
-	themeStore.set({ theme, isDark });
+  if (theme.includes(' ')) {
+    theme = theme.split(' ')[1].trim();
+  }
+  const isDark = darkThemes.includes(theme);
+  console.log('Setting theme', theme);
+  themeStore.set({ theme, isDark });
+  logEvent('themeChange', { theme, isDark });
 };

src/lib/util/util.ts

@@ -1,24 +1,61 @@
-import type { State } from '$lib/types';
 import { initURLSubscription, loadState, updateCodeStore } from './state';
 import { analytics, initAnalytics } from './stats';
 import { loadDataFromUrl } from './fileLoaders/loader';
 import { initLoading } from './loading';
+import { applyMigrations } from './migrations';
+import { init } from './mermaid';
 
 export const loadStateFromURL = (): void => {
-	loadState(window.location.hash.slice(1));
+  loadState(window.location.hash.slice(1));
 };
 
 export const syncDiagram = (): void => {
-	updateCodeStore({
-		updateDiagram: true
-	} as State);
+  updateCodeStore({
+    updateDiagram: true
+  });
 };
 
 export const initHandler = async (): Promise<void> => {
-	loadStateFromURL();
-	await initLoading('Loading Gist...', loadDataFromUrl().catch(console.error));
-	syncDiagram();
-	initURLSubscription();
-	await initAnalytics();
-	analytics?.page();
+  applyMigrations();
+  await initLoading('Loading Mermaid...', init());
+  loadStateFromURL();
+  await initLoading('Loading Gist...', loadDataFromUrl().catch(console.error));
+  syncDiagram();
+  initURLSubscription();
+  await initAnalytics();
+  analytics?.page();
 };
+
+export const isMac = navigator.platform.toUpperCase().indexOf('MAC') >= 0;
+export const cmdKey = isMac ? 'Cmd' : 'Ctrl';
+
+let count = 0;
+export const errorDebug = (limit = 100) => {
+  count += 1;
+  if (count > limit) {
+    console.log(count, limit);
+    // eslint-disable-next-line no-debugger
+    debugger;
+  }
+};
+
+// To queue async tasks so they are executed one after the other, not concurrently.
+export class AsyncQueue<T> {
+  private readonly queue: T[] = [];
+  private running = false;
+  constructor(private processor: (item: T) => Promise<void>) {}
+  public async process(item: T): Promise<void> {
+    this.queue.push(item);
+    if (this.running) {
+      return;
+    }
+    this.running = true;
+    while (this.queue.length > 0) {
+      const item = this.queue.shift();
+      if (item) {
+        await this.processor(item);
+      }
+    }
+    this.running = false;
+  }
+}

src/routes/+layout.svelte

@@ -0,0 +1,87 @@
+<script lang="ts">
+  import '../app.postcss';
+  import { base } from '$app/paths';
+  import { onMount } from 'svelte';
+  import { loadingStateStore } from '$lib/util/loading';
+  import { setTheme, themeStore } from '$lib/util/theme';
+  import { toggleDarkTheme } from '$lib/util/state';
+  import { initHandler } from '$lib/util/util';
+
+  // This can be removed once https://github.com/sveltejs/kit/issues/1612 is fixed.
+  // Then move it into src and vite will bundle it automatically.
+  onMount(() => {
+    window.addEventListener('hashchange', async (ev) => {
+      await initHandler();
+    });
+    if ('serviceWorker' in navigator) {
+      navigator.serviceWorker
+        .register(`${base}/service-worker.js`, {
+          scope: `${base}/`
+        })
+        .then(function (registration) {
+          console.log('Registration successful, scope is:', registration.scope);
+        })
+        .catch(function (error) {
+          console.log('Service worker registration failed, error:', error);
+        });
+    }
+
+    const isDarkMode = window.matchMedia('(prefers-color-scheme: dark)').matches;
+
+    if ($themeStore.theme === undefined) {
+      setTheme(isDarkMode ? 'dark' : 'light');
+    }
+
+    themeStore.subscribe(({ theme, isDark }) => {
+      if (theme) {
+        document.getElementsByTagName('html')[0].setAttribute('data-theme', theme);
+        toggleDarkTheme(isDark);
+      }
+    });
+  });
+</script>
+
+<main class="h-screen text-primary-content">
+  <slot />
+</main>
+
+{#if $loadingStateStore.loading}
+  <div
+    class="w-screen h-screen z-50 absolute left-0 top-0 bg-gray-600 opacity-50 flex align-middle justify-center">
+    <div class="text-indigo-100 text-4xl font-bold my-auto">
+      <div class="loader mx-auto" />
+      <div>{$loadingStateStore.message}</div>
+    </div>
+  </div>
+{/if}
+
+<style>
+  .loader {
+    border: 0.45em solid #f3f3f3;
+    border-radius: 50%;
+    border-top: 0.45em solid #6365f1;
+    width: 3em;
+    height: 3em;
+    -webkit-animation: spin 2s linear infinite; /* Safari */
+    animation: spin 2s linear infinite;
+  }
+
+  /* Safari */
+  @-webkit-keyframes spin {
+    0% {
+      -webkit-transform: rotate(0deg);
+    }
+    100% {
+      -webkit-transform: rotate(360deg);
+    }
+  }
+
+  @keyframes spin {
+    0% {
+      transform: rotate(0deg);
+    }
+    100% {
+      transform: rotate(360deg);
+    }
+  }
+</style>