test(google-workspace): type and shrink empty Gmail search regression test

Replace the hand-rolled fake service with MagicMock, patch through
monkeypatch, and annotate the test and gmail_search().

skills/productivity/google-workspace/scripts/google_api.py

@@ -275,7 +275,7 @@ def build_service(api, version):
 # =========================================================================
 
 
-def gmail_search(args):
+def gmail_search(args: argparse.Namespace) -> None:
     if _gws_binary():
         results = _run_gws(
             ["gmail", "users", "messages", "list"],

tests/skills/test_google_workspace_api.py

@@ -197,26 +197,16 @@ def test_api_get_credentials_refresh_persists_authorized_user_type(api_module, m
     assert saved["type"] == "authorized_user"
 
 
-def test_gmail_search_empty_result_prints_json_array(api_module, capsys):
-    """Regression for #131711: an empty Gmail search through the Python
-    fallback printed "No messages found." instead of the JSON array the gws
-    backend emits, breaking consumers that parse search output as JSON."""
-
-    class EmptyGmail:
-        def users(self):
-            return self
-
-        def messages(self):
-            return self
-
-        def list(self, **_kwargs):
-            return self
-
-        def execute(self):
-            return {"resultSizeEstimate": 0}
-
-    api_module._gws_binary = lambda: None
-    api_module.build_service = lambda *_args, **_kwargs: EmptyGmail()
+def test_gmail_search_empty_result_prints_json_array(
+    api_module: types.ModuleType,
+    monkeypatch: pytest.MonkeyPatch,
+    capsys: pytest.CaptureFixture[str],
+) -> None:
+    """Python-fallback empty search prints [] like the gws path (#131711)."""
+    service = MagicMock()
+    service.users().messages().list().execute.return_value = {"resultSizeEstimate": 0}
+    monkeypatch.setattr(api_module, "_gws_binary", lambda: None)
+    monkeypatch.setattr(api_module, "build_service", lambda *_args: service)
 
     api_module.gmail_search(api_module.argparse.Namespace(query="is:unread", max=10))