failed NO_PATCH NO_PATCH UNSUBMITTED empty_patch(None) · None tool calls · 0 s · fastapi/fastapi
✨ Add support for wrapped functions (e.g. `@functools.wraps()`) used with forward references
Fixes #5065 where the `globalns` computation in `get_typed_signature` misses an edge case handled by `typing.get_type_hints`. This PR makes the logic similar to `get_type_hints`.
## Background
`functools.wraps` updates the annotations and type signature to match the wrapped function. However, it copies the `__annotations__` dict verbatim, including forward references (strings). `get_type_hints` handles this by [dereferencing the `__wrapped__` attribute](https://github.com/python/cpython/blob/576dd901170af30fc50b0a7f07a388b38fd724a9/Lib/typing.py#L2314-L2315) until it gets to the original function, then uses the `__globals__` of _that_ function.
## Testing
I added a test case which reproduced the `NameError` seen in #5065. The test passes after my commit updating the implementation of `get_typed_signature`:
```
tests/test_wrapped_method_forward_reference.py:24:
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
fastapi/routing.py:617: in decorator
self.add_api_route(
fastapi/routing.py:556: in add_api_route
route = route_class(
fastapi/routing.py:425: in __init__
self.dependant = get_dependant(path=self.path_format, call=self.endpoint)
fastapi/dependencies/utils.py:279: in get_dependant
endpoint_signature = get_typed_signature(call)
fastapi/dependencies/utils.py:249: in get_typed_signature
typed_params = [
fastapi/dependencies/utils.py:254: in <listcomp>
annotation=get_typed_annotation(param, globalns),
fastapi/dependencies/utils.py:266: in get_typed_annotation
annotation = evaluate_forwardref(annotation, globalns, globalns)
pydantic/typing.py:76: in pydantic.typing.evaluate_forwardref
???
../../.pyenv/versions/3.9.1/lib/python3.9/typing.py:533: in _evaluate
eval(self.__forward_code__, globalns, localns),
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
> ???
E NameError: name 'ForwardRef' is not defined
<string>:1: NameError
============================================================== short test summary info ===============================================================
FAILED tests/test_wrapped_method_forward_reference.py::test_wrapped_method_type_inference - NameError: name 'ForwardRef' is not defined
================================================================= 1 failed in 0.59s ==================================================================
```| # | Tool | Arguments | Result |
|---|---|---|---|
| No trace captured. | |||
F
=================================== FAILURES ===================================
______________________ test_wrapped_method_type_inference ______________________
def test_wrapped_method_type_inference():
"""
Regression test ensuring that when a method imported from another module
is decorated with something that sets the __wrapped__ attribute (functools.wraps),
then the types are still processed correctly, including dereferencing of forward
references.
"""
app = FastAPI()
client = TestClient(app)
app.post("/endpoint")(passthrough(forwardref_method))
app.post("/endpoint2")(passthrough(passthrough(forwardref_method)))
with client:
response = client.post("/endpoint", json={"input": {"x": 0}})
response2 = client.post("/endpoint2", json={"input": {"x": 0}})
> assert response.json() == response2.json() == {"x": 1}
E AssertionError: assert {'detail': [{...nput': None}]} == {'x': 1}
E
E Left contains 1 more item:
E {'detail': [{'input': None,
E 'loc': ['query', 'input'],
E 'msg': 'Field required',
E 'type': 'missing'}]}
E Right contains 1 more item:
E {'x': 1}
E Use -v to get more diff
tests/test_wrapped_method_forward_reference.py:31: AssertionError
=============================== warnings summary ===============================
../../../../../../../Users/jp/repos/kaggle-gemini-coding-agent-post-training/.envs/overlays/starlette-0.50.0-py3-none-any/starlette/testclient.py:45
/Users/jp/repos/kaggle-gemini-coding-agent-post-training/.envs/overlays/starlette-0.50.0-py3-none-any/starlette/testclient.py:45: DeprecationWarning: The anyio.abc.BlockingPortal alias is deprecated, use anyio.from_thread.BlockingPortal instead.
_PortalFactoryType = Callable[[], AbstractContextManager[anyio.abc.BlockingPortal]]
-- Docs: https://docs.pytest.org/en/stable/how-to/capture-warnings.html
!!!!!!!!!!!!!!!!!!!!!!!!!! stopping after 1 failures !!!!!!!!!!!!!!!!!!!!!!!!!!!
1 failed, 1 warning in 0.66s