fix: label on GitHub Enterprise and when another run creates the label first

Author: shenxianpeng

README.md

@@ -80,7 +80,7 @@ runners need a few tools — see [Good to know](#good-to-know).
 | `author-email` | `false` | Check each commit's author email |
 | `pr-title` | `false` | Check the pull request title against Conventional Commits — the one that matters for squash merges. Pull request events only |
 | `pr-body` | `false` | Check the pull request description against the AI rules of `cchk.toml` (`ai_attribution`) only. Pull request events only |
-| `ai-label` | `false` | Label the pull request when an AI tool wrote any of it (a commit, the description, or an agent's app that opened it): `true` for `ai-assisted`, or the label's name. Labels are only added, never removed. Needs `pull-requests: write`; skipped on fork pull requests |
+| `ai-label` | `false` | Label the pull request when an AI tool wrote any of it (a commit, the description, or an agent's app that opened it): `true` for `ai-assisted`, or the label's name. Labels are only added, never removed. Needs `pull-requests: write`; skipped on fork pull requests under `pull_request` |
 | `pr-comments` | `false` | Post the report as a pull request comment, edited in place on later runs. Needs `pull-requests: write`; skipped on fork pull requests |
 | `job-summary` | `true` | Write the report to the job summary |
 | `dry-run` | `false` | Report failures as warnings and always exit 0 |

main.py

@@ -1911,7 +1911,8 @@ def add_ai_label(results: list[ScopeResult]) -> None:
         if not repo_name:
             raise ValueError("GITHUB_REPOSITORY is not set")
         pr_number = get_pr_number()
-        repo = Github(auth=Auth.Token(token)).get_repo(repo_name)
+        api_url = os.getenv("GITHUB_API_URL", "https://api.github.com")
+        repo = Github(auth=Auth.Token(token), base_url=api_url).get_repo(repo_name)
         issue = repo.get_issue(pr_number)
         if any(label.name == name for label in issue.labels):
             print(f"PR #{pr_number} already has the label '{name}' ({found}).")
@@ -1921,9 +1922,14 @@ def add_ai_label(results: list[ScopeResult]) -> None:
         except GithubException as e:
             if e.status != 404:
                 raise
-            repo.create_label(
-                name, AI_LABEL_COLOR, "Written with the help of an AI tool"
-            )
+            try:
+                repo.create_label(
+                    name, AI_LABEL_COLOR, "Written with the help of an AI tool"
+                )
+            except GithubException as created:
+                # 422: another run created it in the meantime; use that one.
+                if created.status != 422:
+                    raise
         issue.add_to_labels(name)
         print(f"Added the label '{name}' to PR #{pr_number}: {found}.")
     except GithubException as e:

main_test.py

@@ -3784,7 +3784,9 @@ class TestAddAiLabel(unittest.TestCase):
     def setUp(self):
         main.PR_BODY_AI_TOOLS.clear()
 
-    def _run(self, results, label="true", labels=(), get_label=None, add=None):
+    def _run(
+        self, results, label="true", labels=(), get_label=None, add=None, create=None
+    ):
         issue = MagicMock()
         issue.labels = [MagicMock() for _ in labels]
         for mock_label, name in zip(issue.labels, labels):
@@ -3795,6 +3797,8 @@ def _run(self, results, label="true", labels=(), get_label=None, add=None):
         repo.get_issue.return_value = issue
         if get_label is not None:
             repo.get_label.side_effect = get_label
+        if create is not None:
+            repo.create_label.side_effect = create
         github_module = MagicMock()
         github_module.GithubException = _StubGithubException
         github_module.Github.return_value.get_repo.return_value = repo
@@ -3807,6 +3811,7 @@ def _run(self, results, label="true", labels=(), get_label=None, add=None):
                     "GITHUB_REPOSITORY": "owner/repo",
                     "GITHUB_EVENT_NAME": "pull_request",
                     "GITHUB_REF": "refs/pull/12/merge",
+                    "GITHUB_API_URL": "https://ghe.example.com/api/v3",
                 },
             ),
             patch("main.is_fork_pr_with_readonly_token", return_value=False),
@@ -3841,6 +3846,30 @@ def test_creates_a_missing_label(self):
         )
         issue.add_to_labels.assert_called_once_with("ai-assisted")
 
+    def test_uses_the_api_url_of_the_server(self):
+        _repo, _issue, _printed, github_module = self._run([self.AI_SCOPE])
+        self.assertEqual(
+            github_module.Github.call_args.kwargs["base_url"],
+            "https://ghe.example.com/api/v3",
+        )
+
+    def test_a_label_created_meanwhile_is_still_added(self):
+        _repo, issue, printed, _ = self._run(
+            [self.AI_SCOPE],
+            get_label=_StubGithubException(404),
+            create=_StubGithubException(422),
+        )
+        issue.add_to_labels.assert_called_once_with("ai-assisted")
+        self.assertIn("Added the label 'ai-assisted' to PR #12: Claude Code.", printed)
+
+    def test_a_label_that_cannot_be_created_is_not_added(self):
+        _repo, issue, _printed, _ = self._run(
+            [self.AI_SCOPE],
+            get_label=_StubGithubException(404),
+            create=_StubGithubException(403),
+        )
+        issue.add_to_labels.assert_not_called()
+
     def test_already_labelled(self):
         _repo, issue, printed, _ = self._run([self.AI_SCOPE], labels=("ai-assisted",))
         issue.add_to_labels.assert_not_called()