1 files changed, 110 insertions, 0 deletions
diff --git a/llvm_tools/check_clang_diags_test.py b/llvm_tools/check_clang_diags_test.py
new file mode 100755
index 00000000..a7889038
--- /dev/null
+++ b/llvm_tools/check_clang_diags_test.py
@@ -0,0 +1,110 @@
+#!/usr/bin/env python3
+# Copyright 2022 The ChromiumOS Authors
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+"""Tests for check_clang_diags."""
+
+import unittest
+from unittest import mock
+
+import check_clang_diags
+from cros_utils import bugs
+
+
+# pylint: disable=protected-access
+
+
+class Test(unittest.TestCase):
+    """Test class."""
+
+    def test_process_new_diagnostics_ignores_new_tools(self):
+        new_state, new_diags = check_clang_diags._process_new_diagnostics(
+            old={},
+            new={"clang": ["-Wone", "-Wtwo"]},
+        )
+        self.assertEqual(new_state, {"clang": ["-Wone", "-Wtwo"]})
+        self.assertEqual(new_diags, {})
+
+    def test_process_new_diagnostics_is_a_nop_when_no_changes(self):
+        new_state, new_diags = check_clang_diags._process_new_diagnostics(
+            old={"clang": ["-Wone", "-Wtwo"]},
+            new={"clang": ["-Wone", "-Wtwo"]},
+        )
+        self.assertEqual(new_state, {"clang": ["-Wone", "-Wtwo"]})
+        self.assertEqual(new_diags, {})
+
+    def test_process_new_diagnostics_ignores_removals_and_readds(self):
+        new_state, new_diags = check_clang_diags._process_new_diagnostics(
+            old={"clang": ["-Wone", "-Wtwo"]},
+            new={"clang": ["-Wone"]},
+        )
+        self.assertEqual(new_diags, {})
+        new_state, new_diags = check_clang_diags._process_new_diagnostics(
+            old=new_state,
+            new={"clang": ["-Wone", "-Wtwo"]},
+        )
+        self.assertEqual(new_state, {"clang": ["-Wone", "-Wtwo"]})
+        self.assertEqual(new_diags, {})
+
+    def test_process_new_diagnostics_complains_when_warnings_are_added(self):
+        new_state, new_diags = check_clang_diags._process_new_diagnostics(
+            old={"clang": ["-Wone"]},
+            new={"clang": ["-Wone", "-Wtwo"]},
+        )
+        self.assertEqual(new_state, {"clang": ["-Wone", "-Wtwo"]})
+        self.assertEqual(new_diags, {"clang": ["-Wtwo"]})
+
+    @mock.patch.object(bugs, "CreateNewBug")
+    def test_bugs_are_created_as_expected(self, create_new_bug_mock):
+        check_clang_diags._file_bugs_for_new_diags(
+            {
+                "clang": ["-Wone"],
+                "clang-tidy": ["bugprone-foo"],
+            }
+        )
+
+        expected_calls = [
+            mock.call(
+                component_id=bugs.WellKnownComponents.CrOSToolchainPublic,
+                title="Investigate clang check `-Wone`",
+                body="\n".join(
+                    (
+                        "It seems that the `-Wone` check was recently added to clang.",
+                        "It's probably good to TAL at whether this check would be good",
+                        "for us to enable in e.g., platform2, or across ChromeOS.",
+                    )
+                ),
+                assignee=check_clang_diags._DEFAULT_ASSIGNEE,
+                cc=check_clang_diags._DEFAULT_CCS,
+            ),
+            mock.call(
+                component_id=bugs.WellKnownComponents.CrOSToolchainPublic,
+                title="Investigate clang-tidy check `bugprone-foo`",
+                body="\n".join(
+                    (
+                        "It seems that the `bugprone-foo` check was recently added to "
+                        "clang-tidy.",
+                        "It's probably good to TAL at whether this check would be good",
+                        "for us to enable in e.g., platform2, or across ChromeOS.",
+                    )
+                ),
+                assignee=check_clang_diags._DEFAULT_ASSIGNEE,
+                cc=check_clang_diags._DEFAULT_CCS,
+            ),
+        ]
+
+        # Don't assertEqual the lists, since the diff is really hard to read for
+        # that.
+        for actual, expected in zip(
+            create_new_bug_mock.call_args_list, expected_calls
+        ):
+            self.assertEqual(actual, expected)
+
+        self.assertEqual(
+            len(create_new_bug_mock.call_args_list), len(expected_calls)
+        )
+
+
+if __name__ == "__main__":
+    unittest.main()