chore: replace black with ruff in pre-commit

.pre-commit-config.yaml

@@ -15,10 +15,12 @@ repos:
     -   id: trailing-whitespace
     -   id: name-tests-test
     -   id: requirements-txt-fixer
--   repo: https://github.com/psf/black-pre-commit-mirror
-    rev: 26.10.0
+-   repo: https://github.com/astral-sh/ruff-pre-commit
+    rev: v0.17.4
     hooks:
-      - id: black
+    -   id: ruff-check
+        args: [ --fix ]
+    -   id: ruff-format
 -   repo: https://github.com/pre-commit/mirrors-mypy
     rev: v2.4.0
     hooks:

main.py

@@ -282,7 +282,7 @@ def get_pr_event() -> dict[str, Any]:
         with open(event_path, "r", encoding="utf-8") as f:
             event = json.load(f)
         return event.get("pull_request") or {}
-    except Exception as e:
+    except Exception as e:  # noqa: BLE001 - a bad payload warns, never fails the step
         print(f"::warning::Failed to read the PR from the event: {e}", file=sys.stderr)
         return {}
 
@@ -302,8 +302,7 @@ def _rev_resolves(rev: str) -> bool:
     try:
         result = subprocess.run(
             ["git", "rev-parse", "--verify", "--quiet", f"{rev}^{{commit}}"],
-            stdout=subprocess.PIPE,
-            stderr=subprocess.PIPE,
+            capture_output=True,
             encoding="utf-8",
             check=False,
         )
@@ -317,8 +316,7 @@ def _fetch_commit(sha: str) -> bool:
     try:
         result = subprocess.run(
             ["git", "fetch", "--no-tags", "--quiet", "--depth=1", "origin", sha],
-            stdout=subprocess.PIPE,
-            stderr=subprocess.PIPE,
+            capture_output=True,
             encoding="utf-8",
             check=False,
         )
@@ -392,7 +390,7 @@ def get_pr_title() -> str | None:
         with open(event_path, "r", encoding="utf-8") as f:
             event = json.load(f)
         return event.get("pull_request", {}).get("title")
-    except Exception as e:
+    except Exception as e:  # noqa: BLE001 - a bad payload warns, never fails the step
         print(f"::warning::Failed to read PR title from event: {e}", file=sys.stderr)
         return None
 
@@ -427,8 +425,7 @@ def _messages_in_range(revision_range: str) -> list[Commit]:
     """Commits in ``revision_range`` as ``(sha, message)``, oldest first, or ``[]``."""
     result = subprocess.run(
         ["git", "log", COMMIT_LOG_FORMAT, "--reverse", revision_range],
-        stdout=subprocess.PIPE,
-        stderr=subprocess.PIPE,
+        capture_output=True,
         encoding="utf-8",
         check=False,
     )
@@ -446,8 +443,7 @@ def head_sha() -> str:
     try:
         result = subprocess.run(
             ["git", "rev-parse", "HEAD"],
-            stdout=subprocess.PIPE,
-            stderr=subprocess.PIPE,
+            capture_output=True,
             encoding="utf-8",
             check=False,
         )
@@ -555,7 +551,7 @@ def get_pr_commit_messages() -> list[Commit]:
                 "the others were not checked",
             )
         return messages
-    except Exception as e:
+    except Exception as e:  # noqa: BLE001 - warn, then check what we have
         print(
             f"::warning::Failed to retrieve PR commit messages: {e}",
             file=sys.stderr,
@@ -602,8 +598,7 @@ def run_check_json(
     result = subprocess.run(
         command,
         input=input_text,
-        stdout=subprocess.PIPE,
-        stderr=subprocess.PIPE,
+        capture_output=True,
         text=True,
         encoding="utf-8",
         check=False,
@@ -1414,7 +1409,7 @@ def _commit_check_version() -> str:
         from importlib.metadata import version
 
         return version("commit-check")
-    except Exception:
+    except Exception:  # noqa: BLE001 - the version is decoration, never fail on it
         return ""
 
 
@@ -1564,7 +1559,7 @@ def is_fork_pr() -> bool:
         return bool(
             head_full_name and base_full_name and head_full_name != base_full_name
         )
-    except Exception:
+    except Exception:  # noqa: BLE001 - an unreadable payload is not a fork PR
         return False
 
 
@@ -1600,7 +1595,7 @@ def get_pr_number() -> int:
             )
             if number:
                 return int(number)
-        except Exception:
+        except Exception:  # noqa: BLE001, S110 - fall through to the error below
             pass
     raise ValueError(
         "Unable to determine PR number from GITHUB_REF or GITHUB_EVENT_PATH"
@@ -1611,7 +1606,7 @@ def _is_bot(comment: Any) -> bool:
     """Whether a comment was posted by a bot account rather than a person."""
     try:
         return comment.user.type == "Bot"
-    except Exception:
+    except Exception:  # noqa: BLE001 - an unknown author is not a bot
         return False
 
 
@@ -1737,7 +1732,7 @@ def add_pr_comments(results: list[ScopeResult]) -> int:
         # comment is absent, and nothing says why.
         print(f"::warning::Unable to post PR comment: {e}", file=sys.stderr)
         return 0
-    except Exception as e:
+    except Exception as e:  # noqa: BLE001 - the comment is best-effort
         print(f"::warning::Unable to post PR comment: {e}", file=sys.stderr)
         return 0
 

main_test.py

@@ -14,7 +14,7 @@
 
 os.environ.setdefault("GITHUB_STEP_SUMMARY", "/tmp/step_summary.txt")
 
-import main  # noqa: E402
+import main
 
 #: The report footer names the installed commit-check version, which differs
 #: between a contributor's machine and CI. Golden tests pin it so they assert on
@@ -313,7 +313,7 @@ def test_invalid_json_returns_none(self):
 class TestRunCheckJson(unittest.TestCase):
     def test_parses_json_output(self):
         mock_result = MagicMock(returncode=0, stdout=json_output(make_check("branch")))
-        with patch("main.subprocess.run", return_value=mock_result) as mock_run:
+        with patch("main.subprocess.run", return_value=mock_result):
             rc, data, raw = main.run_check_json(["--branch"])
         self.assertEqual(rc, 0)
         self.assertEqual(data["status"], "pass")
@@ -757,7 +757,7 @@ def test_pr_title_check_runs_when_enabled(self):
             ) as mock_scope,
             patch("main.run_other_checks", return_value=[]),
         ):
-            rc, results = main.run_commit_check()
+            rc, _results = main.run_commit_check()
         self.assertEqual(rc, 0)
         mock_scope.assert_called_once_with(
             "PR title", ["--message"], input_text="feat: a feature"
@@ -775,7 +775,7 @@ def test_pr_title_failure_propagates(self):
             patch("main.check_scope", return_value=fail_scope("PR title")),
             patch("main.run_other_checks", return_value=[]),
         ):
-            rc, results = main.run_commit_check()
+            rc, _results = main.run_commit_check()
         self.assertEqual(rc, 1)
 
     def test_pr_title_skipped_outside_pr_context(self):
@@ -789,7 +789,7 @@ def test_pr_title_skipped_outside_pr_context(self):
             patch("main.get_pr_title") as mock_title,
             patch("main.run_other_checks", return_value=[]),
         ):
-            rc, results = main.run_commit_check()
+            rc, _results = main.run_commit_check()
         self.assertEqual(rc, 0)
         mock_title.assert_not_called()
 
@@ -825,7 +825,7 @@ def test_non_pr_message_check_uses_commit_message_scope(self):
             ) as mock_scope,
             patch("main.run_other_checks", return_value=[]),
         ):
-            rc, results = main.run_commit_check()
+            rc, _results = main.run_commit_check()
         self.assertEqual(rc, 0)
         mock_pr.assert_not_called()
         # HEAD is the commit that was checked, so the scope names it too.
@@ -882,7 +882,7 @@ def test_pr_without_enumerable_commits_warns_and_checks_head(self):
             ) as mock_scope,
             patch("main.run_other_checks", return_value=[]),
         ):
-            rc, results, output = self._run_capturing_stdout()
+            rc, _results, output = self._run_capturing_stdout()
         self.assertEqual(rc, 0)
         self.assertIn(self.SHALLOW_PR_WARNING, output)
         mock_scope.assert_called_once_with("Commit message", ["--message"], sha="")
@@ -1162,9 +1162,7 @@ def _run(self, total, api_commits, head="b2"):
             for sha, msg in api_commits
         ]
         github_module = MagicMock()
-        github_module.Github.return_value.get_repo.return_value.get_pull.return_value = (
-            pull
-        )
+        github_module.Github.return_value.get_repo.return_value.get_pull.return_value = pull
         env = {
             "GITHUB_TOKEN": "token",
             "GITHUB_REPOSITORY": "owner/repo",
@@ -1554,7 +1552,7 @@ def test_annotation_payload_is_escaped(self):
             ],
         )
         output = self._run([scope])
-        annotation = [ln for ln in output.splitlines() if ln.startswith("::error")][0]
+        annotation = next(ln for ln in output.splitlines() if ln.startswith("::error"))
         self.assertNotIn("\n", annotation.removeprefix("::error "))
         self.assertIn("first line", annotation)
 
@@ -3391,17 +3389,19 @@ def test_the_two_streams_are_read_separately(self):
         mock_result = MagicMock(returncode=0, stdout="{}", stderr="")
         with patch("main.subprocess.run", return_value=mock_result) as mock_run:
             main.run_check_json(["--branch"])
-        self.assertIs(mock_run.call_args[1]["stderr"], main.subprocess.PIPE)
+        self.assertIs(mock_run.call_args[1]["capture_output"], True)
 
     def test_a_notice_does_not_break_the_json(self):
         mock_result = MagicMock(
             returncode=0,
             stdout=json_output(make_check("branch")),
             stderr=self.NOTICE,
         )
-        with patch("main.subprocess.run", return_value=mock_result):
-            with patch.object(sys, "stderr", io.StringIO()):
-                rc, data, raw = main.run_check_json(["--branch"])
+        with (
+            patch("main.subprocess.run", return_value=mock_result),
+            patch.object(sys, "stderr", io.StringIO()),
+        ):
+            rc, data, _raw = main.run_check_json(["--branch"])
         self.assertEqual(rc, 0)
         self.assertIsNotNone(data)
         self.assertEqual(data["status"], "pass")
@@ -3410,9 +3410,11 @@ def test_a_notice_does_not_break_the_json(self):
 
     def test_a_notice_alone_does_not_fail_the_scope(self):
         mock_result = MagicMock(returncode=0, stdout=json_output(), stderr=self.NOTICE)
-        with patch("main.subprocess.run", return_value=mock_result):
-            with patch.object(sys, "stderr", io.StringIO()):
-                scope = main.check_scope("Branch", ["--branch"])
+        with (
+            patch("main.subprocess.run", return_value=mock_result),
+            patch.object(sys, "stderr", io.StringIO()),
+        ):
+            scope = main.check_scope("Branch", ["--branch"])
         self.assertEqual(scope.status, "pass")
         self.assertEqual(scope.raw_text, "")
 
@@ -3421,10 +3423,12 @@ def test_notices_reach_the_job_log_once(self):
             returncode=0, stdout=json_output(make_check("branch")), stderr=self.NOTICE
         )
         fake_err = io.StringIO()
-        with patch("main.subprocess.run", return_value=mock_result):
-            with patch.object(sys, "stderr", fake_err):
-                for _ in range(3):
-                    main.run_check_json(["--branch"])
+        with (
+            patch("main.subprocess.run", return_value=mock_result),
+            patch.object(sys, "stderr", fake_err),
+        ):
+            for _ in range(3):
+                main.run_check_json(["--branch"])
         printed = fake_err.getvalue()
         self.assertIn("--branch requested but no branch rules are configured", printed)
         # Once, not once per scope and per commit in the pull request.
@@ -3434,9 +3438,11 @@ def test_unparsable_output_keeps_both_streams(self):
         mock_result = MagicMock(
             returncode=2, stdout="", stderr="Error: cchk.toml: Expected ']'\n"
         )
-        with patch("main.subprocess.run", return_value=mock_result):
-            with patch.object(sys, "stderr", io.StringIO()):
-                scope = main.check_scope("Branch", ["--branch"])
+        with (
+            patch("main.subprocess.run", return_value=mock_result),
+            patch.object(sys, "stderr", io.StringIO()),
+        ):
+            scope = main.check_scope("Branch", ["--branch"])
         self.assertEqual(scope.status, "fail")
         self.assertIn("Expected ']'", scope.raw_text)