refactor: keep only the AI rules in the Action, no new CLI flag

message-ai-attribution now runs the usual --message check and keeps
CC013 to CC017 from its result, so it works with the commit-check
already pinned (2.20.2) and needs no --message-ai-attribution in the
CLI. Under ai_attribution = "ignore" the scope reads as skipped.

Author: shenxianpeng

main.py

@@ -91,16 +91,8 @@ def _reconfigure_io() -> None:
 MESSAGE_AI_ATTRIBUTION_ENABLED = env_flag("MESSAGE_AI_ATTRIBUTION")
 
 
-def message_check_args() -> list[str]:
-    """The CLI flag each commit message is checked with.
-
-    ``message-ai-attribution: true`` narrows the check to the AI rules (CC013
-    to CC017), whatever ``message`` says: ``message`` defaults to true, so
-    asking for the AI rules alone must not need it turned off as well.
-    """
-    if MESSAGE_AI_ATTRIBUTION_ENABLED:
-        return ["--message-ai-attribution"]
-    return ["--message"]
+#: The AI attribution rules: what ``message-ai-attribution: true`` keeps.
+AI_RULE_IDS = frozenset({"CC013", "CC014", "CC015", "CC016", "CC017"})
 
 
 #: The label ``ai-label: true`` puts on a pull request that an AI tool wrote.
@@ -476,6 +468,22 @@ def skip_when_no_ai_rule_ran(scope: ScopeResult) -> ScopeResult:
     return scope
 
 
+def keep_ai_rules(scope: ScopeResult) -> ScopeResult:
+    """Narrow a commit message scope to the AI rules (CC013 to CC017).
+
+    ``message-ai-attribution: true`` does this whatever ``message`` says:
+    ``message`` defaults to true, so asking for the AI rules alone must not
+    need it turned off as well. The CLI runs every message rule and the
+    format rules' verdicts are dropped here, so the CLI needs no flag of
+    its own for it. A scope left with no rule, under the default
+    ``ai_attribution = "ignore"``, is reported as skipped.
+    """
+    if not MESSAGE_AI_ATTRIBUTION_ENABLED or scope.raw_text:
+        return scope
+    scope.checks = [c for c in scope.checks if c.get("rule_id") in AI_RULE_IDS]
+    return skip_when_no_ai_rule_ran(scope)
+
+
 def get_pr_title() -> str | None:
     """Read PR title from GitHub event payload."""
     if not is_pr_event():
@@ -834,7 +842,9 @@ def run_pr_message_checks(pr_commits: list[Commit]) -> list[ScopeResult]:
             names = ("GIT_AUTHOR_NAME", "GIT_AUTHOR_EMAIL")
             env = {key: value for key, value in zip(names, author) if value} or None
         results.append(
-            check_scope(label, message_check_args(), input_text=msg, sha=sha, env=env)
+            keep_ai_rules(
+                check_scope(label, ["--message"], input_text=msg, sha=sha, env=env)
+            )
         )
     return results
 
@@ -925,7 +935,7 @@ def run_commit_check() -> tuple[int, list[ScopeResult]]:
     # Outside a PR, check the HEAD commit message directly.
     if "--message" in args:
         results.append(
-            check_scope("Commit message", message_check_args(), sha=head_sha())
+            keep_ai_rules(check_scope("Commit message", ["--message"], sha=head_sha()))
         )
         args = [a for a in args if a != "--message"]
     rev = None

main_test.py

@@ -423,19 +423,53 @@ def test_a_commit_in_the_clone_carries_its_own_author(self):
         self.assertEqual(env["GIT_AUTHOR_EMAIL"], "bot@renovateapp.com")
 
     def test_message_ai_attribution_checks_only_the_ai_rules(self):
-        """The commit still goes in with its author, so CC017 judges it."""
+        """The format rules' verdicts are dropped; the commit still goes in
+        with its author, so CC017 judges it."""
         self.local_author.return_value = ("Jane Dev", "jane@example.com")
-        mock_result = MagicMock(returncode=0, stdout=json_output(make_check("message")))
+        output = json_output(
+            make_check("message", status="fail"),
+            make_check("ai_author", status="fail", rule_id="CC017"),
+            make_check("ai_co_author", rule_id="CC015"),
+        )
+        mock_result = MagicMock(returncode=1, stdout=output)
         with (
             patch("main.MESSAGE_AI_ATTRIBUTION_ENABLED", True),
             patch("main.subprocess.run", return_value=mock_result) as mock_run,
         ):
-            main.run_pr_message_checks([(SHA_A, "WIP")])
+            [scope] = main.run_pr_message_checks([(SHA_A, "WIP")])
         self.assertEqual(
-            mock_run.call_args[0][0],
-            ["commit-check", "--format", "json", "--message-ai-attribution"],
+            mock_run.call_args[0][0], ["commit-check", "--format", "json", "--message"]
         )
         self.assertEqual(mock_run.call_args[1]["env"]["GIT_AUTHOR_NAME"], "Jane Dev")
+        self.assertEqual([c["rule_id"] for c in scope.checks], ["CC017", "CC015"])
+        self.assertEqual(scope.status, "fail")
+
+    def test_message_ai_attribution_passes_a_badly_formatted_message(self):
+        mock_result = MagicMock(
+            returncode=1,
+            stdout=json_output(
+                make_check("message", status="fail"),
+                make_check("subject_min_length", status="fail", rule_id="CC005"),
+                make_check("ai_attribution", rule_id="CC013"),
+            ),
+        )
+        with (
+            patch("main.MESSAGE_AI_ATTRIBUTION_ENABLED", True),
+            patch("main.subprocess.run", return_value=mock_result),
+        ):
+            [scope] = main.run_pr_message_checks([(SHA_A, "WIP")])
+        self.assertEqual(scope.status, "pass")
+
+    def test_message_ai_attribution_under_ignore_is_skipped(self):
+        """No AI rule ran: say so rather than report a pass."""
+        mock_result = MagicMock(returncode=0, stdout=json_output(make_check("message")))
+        with (
+            patch("main.MESSAGE_AI_ATTRIBUTION_ENABLED", True),
+            patch("main.subprocess.run", return_value=mock_result),
+        ):
+            [scope] = main.run_pr_message_checks([(SHA_A, "feat: x")])
+        self.assertEqual(scope.status, "skip")
+        self.assertEqual(scope.checks[0]["reason"], main.AI_POLICY_IGNORED)
 
     def test_a_blank_author_field_is_left_to_git(self):
         self.local_author.return_value = ("Renovate Bot", "")
@@ -1009,9 +1043,7 @@ def test_message_ai_attribution_narrows_the_head_check(self):
             patch("main.run_other_checks", return_value=[]),
         ):
             main.run_commit_check()
-        mock_scope.assert_called_once_with(
-            "Commit message", ["--message-ai-attribution"], sha=SHA_A
-        )
+        mock_scope.assert_called_once_with("Commit message", ["--message"], sha=SHA_A)
 
     def test_message_flag_removed_before_other_checks_in_pr(self):
         captured_args = []