ci: enforce Ruff linting

.github/workflows/ci.yml

@@ -18,6 +18,9 @@ jobs:
           python-version: ${{ matrix.python-version }}
           cache: pip
       - run: pip install -e ".[dev]"
+      - name: Lint with Ruff
+        if: matrix.python-version == '3.12'
+        run: ruff check .
       - run: pytest -q
       # No services, no API keys, no network: it reads local files, so CI runs the real thing.
       - name: Smoke the CLI against the bundled fixture session

CONTRIBUTING.md

@@ -11,7 +11,8 @@ Thanks for considering a contribution — issues and pull requests are welcome.
 ## Making a change
 
 - Keep pull requests focused and describe **what** changed and **why**.
-- Run the project's format, lint, and test steps (see the README) before pushing.
+- Run `ruff check .` and the project's test steps (see the README) before pushing.
+- Formatting is not currently enforced; Ruff is used for linting.
 - Add or update tests when you change behavior.
 - Update docs or the CHANGELOG when relevant.
 

agentrace/checks.py

@@ -16,8 +16,8 @@
 from __future__ import annotations
 
 import re
+from collections.abc import Callable
 from dataclasses import dataclass
-from typing import Callable
 
 from .parse import AgentRun
 
@@ -68,7 +68,7 @@ def check_refused_or_gave_up(run: AgentRun) -> list[Finding]:
     ]
     head = run.result[:1500]
     for p in patterns:
-        m = re.search(p, head, re.I)
+        m = re.search(p, head, re.IGNORECASE)
         if m:
             return [
                 Finding(
@@ -93,11 +93,11 @@ def check_destructive_command(run: AgentRun) -> list[Finding]:
         r"\bkubectl\s+delete\b",
         r":\s*\(\s*\)\s*\{\s*:\s*\|\s*:\s*&\s*\}\s*;\s*:",
     ]
-    caution = re.compile(r"\b(?:dry[- ]?run|backup|verify first|check first|confirm first)\b|--dry-run", re.I)
+    caution = re.compile(r"\b(?:dry[- ]?run|backup|verify first|check first|confirm first)\b|--dry-run", re.IGNORECASE)
     head = run.result[:1500]
 
     for pattern in patterns:
-        m = re.search(pattern, head, re.I)
+        m = re.search(pattern, head, re.IGNORECASE)
         if not m:
             continue
         start = max(0, m.start() - 140)
@@ -132,7 +132,7 @@ def check_unverified_claim(run: AgentRun) -> list[Finding]:
     ]
     hits = []
     for p in hedges:
-        for m in re.finditer(p, run.result, re.I):
+        for m in re.finditer(p, run.result, re.IGNORECASE):
             hits.append(_context(run.result, m.start()))
     if hits:
         return [
@@ -160,7 +160,7 @@ def check_absence_as_evidence(run: AgentRun) -> list[Finding]:
         r"\bboard is empty\b",
     ]
     for p in patterns:
-        m = re.search(p, run.result, re.I)
+        m = re.search(p, run.result, re.IGNORECASE)
         if m:
             return [
                 Finding(
@@ -208,7 +208,7 @@ def check_url_without_verification(run: AgentRun) -> list[Finding]:
     urls = re.findall(r"https?://[^\s)\]<>\"']+", run.result)
     if len(urls) < 5:
         return []
-    verified = re.search(r"\b(?:verified|confirmed|checked|fetched|HTTP 200|status 200)\b", run.result, re.I)
+    verified = re.search(r"\b(?:verified|confirmed|checked|fetched|HTTP 200|status 200)\b", run.result, re.IGNORECASE)
     if not verified:
         return [
             Finding(
@@ -236,7 +236,7 @@ def check_prompt_hygiene(run: AgentRun) -> list[Finding]:
         r"\b(?:output|outputs|return|returns|format|formatted|respond|reply|write|writing|report|"
         r"summar[iy]|list|table|json|csv|markdown|schema|fields|columns|deliver)\b",
         run.prompt,
-        re.I,
+        re.IGNORECASE,
     )
 
     # Length alone is not the defect. "Run the suite and report every failing test as node ids
@@ -274,7 +274,7 @@ def check_unquantified(run: AgentRun) -> list[Finding]:
         r"\b(?:count|counts|how many|number of|enumerate|enumerat(?:e|ing)|"
         r"list (?:every|all|each)|report every|every \w+ as)\b",
         run.prompt,
-        re.I,
+        re.IGNORECASE,
     )
     if not asks_to_count:
         return []
@@ -289,7 +289,7 @@ def check_unquantified(run: AgentRun) -> list[Finding]:
     vague = re.search(
         r"\b(?:several|some|a few|a number of|various|numerous|many|multiple)\b",
         result,
-        re.I,
+        re.IGNORECASE,
     )
     if not vague:
         return []

agentrace/parse.py

@@ -16,10 +16,10 @@
 from __future__ import annotations
 
 import json
+from collections.abc import Iterator
 from dataclasses import dataclass, field
 from datetime import UTC, datetime
 from pathlib import Path
-from typing import Iterator
 
 
 @dataclass
@@ -77,7 +77,7 @@ def _ts(value: str | None) -> datetime | None:
     if not value:
         return None
     try:
-        parsed = datetime.fromisoformat(value.replace("Z", "+00:00"))
+        parsed = datetime.fromisoformat(value)
         # Treat missing offsets as UTC, independently of the reader's local timezone.
         return parsed.replace(tzinfo=UTC) if parsed.tzinfo is None else parsed
     except ValueError:

tests/test_agentrace.py

@@ -11,23 +11,21 @@
 from __future__ import annotations
 
 import json
-from datetime import datetime, timezone
-
-import pytest
+from datetime import UTC, datetime
 
 from agentrace.checks import analyse
 from agentrace.parse import AgentRun, parse_session
 
 
 def _run(result: str = "x" * 500, prompt: str = "y" * 500, **kw) -> AgentRun:
-    defaults = dict(
-        tool_use_id="toolu_test123456",
-        description="test run",
-        prompt=prompt,
-        result=result,
-        started_at=datetime(2026, 7, 16, 12, 0, tzinfo=timezone.utc),
-        ended_at=datetime(2026, 7, 16, 12, 1, tzinfo=timezone.utc),
-    )
+    defaults = {
+        "tool_use_id": "toolu_test123456",
+        "description": "test run",
+        "prompt": prompt,
+        "result": result,
+        "started_at": datetime(2026, 7, 16, 12, 0, tzinfo=UTC),
+        "ended_at": datetime(2026, 7, 16, 12, 1, tzinfo=UTC),
+    }
     defaults.update(kw)
     return AgentRun(**defaults)
 
@@ -292,8 +290,8 @@ def test_unquantified_clean_when_result_has_counts():
 
 def test_slow_run_is_flagged():
     r = _run(
-        started_at=datetime(2026, 7, 16, 12, 0, tzinfo=timezone.utc),
-        ended_at=datetime(2026, 7, 16, 12, 30, tzinfo=timezone.utc),
+        started_at=datetime(2026, 7, 16, 12, 0, tzinfo=UTC),
+        ended_at=datetime(2026, 7, 16, 12, 30, tzinfo=UTC),
     )
     assert "slow_run" in _codes(r)
 

tests/test_destructive_command.py

@@ -1,4 +1,4 @@
-from datetime import datetime, timezone
+from datetime import UTC, datetime
 
 from agentrace.checks import analyse
 from agentrace.parse import AgentRun
@@ -10,8 +10,8 @@ def _run(result: str) -> AgentRun:
         description="test run",
         prompt="Review the operation and report what should be run.",
         result=result,
-        started_at=datetime(2026, 7, 16, 12, 0, tzinfo=timezone.utc),
-        ended_at=datetime(2026, 7, 16, 12, 1, tzinfo=timezone.utc),
+        started_at=datetime(2026, 7, 16, 12, 0, tzinfo=UTC),
+        ended_at=datetime(2026, 7, 16, 12, 1, tzinfo=UTC),
     )