help(MyMessage) crashes

betterproto2/src/betterproto2/__init__.py

@@ -716,6 +716,9 @@ def _betterproto(cls: type[Self]) -> ProtoClassMetadata:  # type: ignore
         try:
             return cls._betterproto_meta
         except AttributeError:
+            if cls is Message:
+                # We can't generate metadata for the base class, only subclasses.
+                return None # type: ignore
             cls._betterproto_meta = ProtoClassMetadata(cls)
             return cls._betterproto_meta
 

betterproto2/tests/README.md

@@ -33,7 +33,7 @@ message Test {
 }
 ```
 
-You can add multiple `.proto` files to the test case, as long as one file matches the directory name. 
+You can add multiple `.proto` files to the test case, as long as one file matches the directory name.
 
 ### json
 
@@ -64,11 +64,11 @@ The following tests are automatically executed for all cases:
 - [x] Can the generated python code be imported?
 - [x] Can the generated message class be instantiated?
 - [x] Is the generated code compatible with the Google's `grpc_tools.protoc` implementation?
-  - _when `.json` is present_ 
+  - _when `.json` is present_
 
 ## Running the tests
 
-- `pipenv run generate`  
+- `pipenv run get-local-compiled-tests`
   This generates:
   - `betterproto/tests/output_betterproto` — *the plugin generated python classes*
   - `betterproto/tests/output_reference` — *reference implementation classes*
@@ -88,4 +88,4 @@ betterproto/tests/test_inputs.py ..x...x..x...x.X........xx........x.....x......
 - `x` — XFAIL: expected failure
 - `X` — XPASS: expected failure, but still passed
 
-Test cases marked for expected failure are declared in [inputs/config.py](inputs/config.py)
+Test cases marked for expected failure are declared in [inputs/config.py](inputs/config.py)

betterproto2/tests/test_documentation.py

@@ -60,3 +60,13 @@ def test_escaping(requires_grpclib) -> None:
     Simple quotes are not escaped "
     """
         )
+
+
+def test_help(requires_grpclib) -> None:
+    """Test that help(Foo) doesn't trigger an error."""
+    from .outputs.documentation.documentation import Test
+
+    # help(Test) triggers help(Message)
+    # which inspects the class attribute Message._betterproto
+    # which is only supposed to be defined on subclasses of Message.
+    help(Test)