handle resume tokens gracefully (#1097)

* Fix telemetry deltas for resumed runs

* Fix resumed telemetry duration

tests/test_telemetry_resume.py

@@ -0,0 +1,89 @@
+"""Regression tests for telemetry emitted by resumed runs."""
+
+from __future__ import annotations
+
+from datetime import UTC, datetime, timedelta
+from typing import Any
+
+import pytest
+from agents.usage import Usage
+
+from strix.report.state import ReportState
+from strix.telemetry import posthog, scarf
+
+
+def _usage(requests: int, input_tokens: int, output_tokens: int, total_tokens: int) -> Usage:
+    return Usage(
+        requests=requests,
+        input_tokens=input_tokens,
+        output_tokens=output_tokens,
+        total_tokens=total_tokens,
+    )
+
+
+def _capture(sent: list[dict[str, Any]], props: dict[str, Any]) -> bool:
+    sent.append(props)
+    return True
+
+
+@pytest.mark.parametrize("telemetry", [posthog, scarf])
+def test_scan_ended_reports_resumed_usage_delta(
+    telemetry: Any,
+    tmp_path: Any,
+    monkeypatch: pytest.MonkeyPatch,
+) -> None:
+    monkeypatch.chdir(tmp_path)
+    initial = ReportState(run_name="resumed")
+    initial.record_sdk_usage(
+        agent_id="agent",
+        usage=_usage(10, 1000, 200, 1200),
+        model="unknown",
+    )
+    initial.record_observed_llm_cost(1.25)
+    initial.end_time = (datetime.now(UTC) - timedelta(hours=1)).isoformat()
+    initial.run_record["end_time"] = initial.end_time
+    initial.save_run_data()
+
+    resumed = ReportState(run_name="resumed")
+    resumed.hydrate_from_run_dir()
+    resumed.record_sdk_usage(
+        agent_id="agent",
+        usage=_usage(3, 300, 50, 350),
+        model="unknown",
+    )
+    resumed.record_observed_llm_cost(0.75)
+
+    sent: list[dict[str, Any]] = []
+    monkeypatch.setattr(telemetry, "_send", lambda _event, props: _capture(sent, props))
+    telemetry.end(resumed)
+
+    assert sent[0]["llm_requests"] == 3
+    assert sent[0]["llm_input_tokens"] == 300
+    assert sent[0]["llm_output_tokens"] == 50
+    assert sent[0]["llm_tokens"] == 350
+    assert sent[0]["llm_cost"] == pytest.approx(0.75)
+    assert 0 <= sent[0]["duration_seconds"] <= 2
+
+
+@pytest.mark.parametrize("telemetry", [posthog, scarf])
+def test_scan_ended_reports_all_fresh_run_usage(
+    telemetry: Any,
+    monkeypatch: pytest.MonkeyPatch,
+) -> None:
+    state = ReportState()
+    state.record_sdk_usage(
+        agent_id="agent",
+        usage=_usage(3, 300, 50, 350),
+        model="unknown",
+    )
+    state.record_observed_llm_cost(0.75)
+
+    sent: list[dict[str, Any]] = []
+    monkeypatch.setattr(telemetry, "_send", lambda _event, props: _capture(sent, props))
+    telemetry.end(state)
+
+    assert sent[0]["llm_requests"] == 3
+    assert sent[0]["llm_input_tokens"] == 300
+    assert sent[0]["llm_output_tokens"] == 50
+    assert sent[0]["llm_tokens"] == 350
+    assert sent[0]["llm_cost"] == pytest.approx(0.75)