Add warnings import for deprecated messages

src/betterproto/plugin/models.py

@@ -299,10 +299,13 @@ def python_module_imports(self) -> Set[str]:
         imports = set()
 
         has_deprecated = False
+        # Check if any messages are marked as deprecated
         if any(m.deprecated for m in self.messages):
             has_deprecated = True
-        if any(x for x in self.messages if any(x.deprecated_fields)):
+        # Check if any fields in any messages are marked as deprecated
+        if any(any(f.deprecated for f in m.fields) for m in self.messages):
             has_deprecated = True
+        # Check if any methods in any services are marked as deprecated
         if any(
             any(m.proto_obj.options.deprecated for m in s.methods)
             for s in self.services

tests/test_deprecated.py

@@ -59,3 +59,17 @@ async def test_service_with_deprecated_method():
     with warnings.catch_warnings():
         warnings.simplefilter("error")
         await stub.func(Empty())
+
+
+def test_warnings_import_for_deprecated_message():
+    """Verify that deprecated messages trigger the warnings import."""
+    with pytest.warns(DeprecationWarning):
+        # This should trigger the warnings import in the generated code
+        Message(value="test")
+
+    # Check that warnings module is properly imported in the generated file
+    import tests.output_betterproto.deprecated as deprecated_module
+
+    assert "warnings" in deprecated_module.__dict__, (
+        "warnings module should be imported for deprecated messages"
+    )