From a7e6ed35c7cf7333731ac72c778761435b39655b Mon Sep 17 00:00:00 2001 From: itsviseph Date: Sun, 5 Apr 2026 13:33:55 +0530 Subject: [PATCH] Add nested forward-ref regression coverage --- fastapi/dependencies/utils.py | 6 +++ ...est_stringified_annotations_forwardrefs.py | 41 +++++++++++++++++++ 2 files changed, 47 insertions(+) diff --git a/fastapi/dependencies/utils.py b/fastapi/dependencies/utils.py index 0477c75ddc..652df06cb6 100644 --- a/fastapi/dependencies/utils.py +++ b/fastapi/dependencies/utils.py @@ -1,3 +1,4 @@ +import builtins import dataclasses import inspect import sys @@ -84,6 +85,8 @@ multipart_not_installed_error = ( class _ForwardRefNamespace(dict[str, Any]): def __missing__(self, key: str) -> Any: + if hasattr(builtins, key): + return getattr(builtins, key) value = ForwardRef(key) self[key] = value return value @@ -253,6 +256,9 @@ def get_typed_signature(call: Callable[..., Any]) -> inspect.Signature: def get_typed_annotation(annotation: Any, globalns: dict[str, Any]) -> Any: if isinstance(annotation, str): try: + # These annotation strings come from Python's own annotation machinery, + # not directly from user input, so evaluating them here matches the + # standard runtime resolution path. annotation = eval(annotation, globalns, globalns) except NameError: # Preserve the outer typing structure (e.g. Annotated[..., Depends(...)]) diff --git a/tests/test_stringified_annotations_forwardrefs.py b/tests/test_stringified_annotations_forwardrefs.py index 5c91a6d1ae..448d40c09b 100644 --- a/tests/test_stringified_annotations_forwardrefs.py +++ b/tests/test_stringified_annotations_forwardrefs.py @@ -77,3 +77,44 @@ async def read_root(potato: Annotated["Potato", Depends(get_potato)]): operation = client.get("/openapi.json").json()["paths"]["/"]["get"] assert "parameters" not in operation + + +@needs_py310 +def test_nested_forwardref_inside_annotated_dependency_preserves_structure(): + app = _build_app(""" +from __future__ import annotations + +from dataclasses import dataclass +from typing import Annotated + +from fastapi import Depends, FastAPI + +app = FastAPI() + +def get_potatoes() -> list[Potato]: + return [Potato(color="red", size=10), Potato(color="gold", size=7)] + +@app.get("/") +async def read_root(potatoes: Annotated[list[Potato], Depends(get_potatoes)]): + return { + "items": [{"color": potato.color, "size": potato.size} for potato in potatoes] + } + +@dataclass +class Potato: + color: str + size: int +""") + client = TestClient(app) + + response = client.get("/") + assert response.status_code == 200, response.text + assert response.json() == { + "items": [ + {"color": "red", "size": 10}, + {"color": "gold", "size": 7}, + ] + } + + operation = client.get("/openapi.json").json()["paths"]["/"]["get"] + assert "parameters" not in operation