ci: enforce canonical issue metadata policy

tests/unit/test_tracker_policy.py

@@ -0,0 +1,62 @@
+import unittest
+from unittest.mock import Mock
+
+from scripts.tracker_policy import (
+    TRIAGE_LABEL,
+    check_pull_request,
+    deliberate_issue_numbers,
+    ensure_issue_label,
+)
+
+
+class TestDeliberateIssueNumbers(unittest.TestCase):
+    def test_accepts_completing_and_noncompleting_forms(self):
+        self.assertEqual(
+            deliberate_issue_numbers("Fixes #12", "Part of #14; refs #15"),
+            {12, 14, 15},
+        )
+
+    def test_does_not_treat_incidental_number_as_link(self):
+        self.assertEqual(deliberate_issue_numbers("Audit #12", "See PR #14"), set())
+
+
+class TestCheckPullRequest(unittest.TestCase):
+    def test_accepts_unlabelled_pr_linked_to_real_issue(self):
+        api = Mock()
+        api.request.return_value = {"number": 12, "pull_request": None}
+        event = {"pull_request": {"title": "Change", "body": "Part of #12", "labels": []}}
+        self.assertEqual(check_pull_request(event, api), [])
+
+    def test_rejects_labels_and_pr_reference(self):
+        api = Mock()
+        api.request.return_value = {"number": 12, "pull_request": {}}
+        event = {
+            "pull_request": {
+                "title": "Change",
+                "body": "Closes #12",
+                "labels": [{"name": "Kind/Bug"}],
+            }
+        }
+        errors = check_pull_request(event, api)
+        self.assertEqual(len(errors), 2)
+        self.assertIn("unlabeled", errors[0])
+        self.assertIn("not an issue", errors[1])
+
+
+class TestEnsureIssueLabel(unittest.TestCase):
+    def test_adds_triage_label_to_unlabelled_issue(self):
+        api = Mock()
+        api.request.side_effect = [[{"id": 55, "name": TRIAGE_LABEL}], None]
+        event = {"issue": {"number": 405, "labels": [], "pull_request": None}}
+        self.assertTrue(ensure_issue_label(event, api))
+        api.request.assert_any_call("POST", "/issues/405/labels", {"labels": [55]})
+
+    def test_leaves_labelled_issue_unchanged(self):
+        api = Mock()
+        event = {"issue": {"number": 405, "labels": [{"name": "Kind/Documentation"}]}}
+        self.assertFalse(ensure_issue_label(event, api))
+        api.request.assert_not_called()
+
+
+if __name__ == "__main__":
+    unittest.main()