fastapi-pytest:如何覆盖接受参数的fastapi依赖项?

我有这个小 MCVE 运行良好的FastAPI应用程序:

# run.py
import uvicorn
from fastapi import FastAPI, Depends

app = FastAPI()


###########

def dep_with_arg(inp):
    def sub_dep():
        return inp
    return sub_dep


@app.get("/a")
def a(v: str = Depends(dep_with_arg("a"))):
    return v


###########


def dep_without_arg():
    return "b"


@app.get("/b")
def b(v: str = Depends(dep_without_arg)):
    return v


###########


def main():
    uvicorn.run(
        "run:app",
        host="0.0.0.0",
        reload=True,
        port=8000,
        workers=1
    )


if __name__ == "__main__":
    main()

注意的依赖项之间的差异 /a 和 /b 端点。在中 /a 端点,我创建了一个接受参数的依赖项。当我调用它们时,两个端点都按预期工作。

我现在尝试在覆盖依赖项的同时测试端点,如下所示:

from run import app, dep_without_arg, dep_with_arg
from starlette.testclient import TestClient


def test_b():
    def dep_override_for_dep_without_arg():
        return "bbb"

    test_client = TestClient(app=app)
    test_client.app.dependency_overrides[dep_without_arg] = dep_override_for_dep_without_arg
    resp = test_client.get("/b")
    resp_json = resp.json()
    assert resp_json == "bbb"


###########


def test_a_method_1():
    def dep_override_for_dep_with_arg(inp):
        def sub_dep():
            return "aaa"

        return sub_dep

    test_client = TestClient(app=app)
    test_client.app.dependency_overrides[dep_with_arg] = dep_override_for_dep_with_arg
    resp = test_client.get(
        "/a",
    )
    resp_json = resp.json()
    assert resp_json == "aaa"


def test_a_method_2():
    def dep_override_for_dep_with_arg(inp):
        return "aaa"

    test_client = TestClient(app=app)
    test_client.app.dependency_overrides[dep_with_arg] = dep_override_for_dep_with_arg
    resp = test_client.get(
        "/a",
    )
    resp_json = resp.json()
    assert resp_json == "aaa"


def test_a_method_3():
    def dep_override_for_dep_with_arg(inp):
        return "aaa"

    test_client = TestClient(app=app)
    test_client.app.dependency_overrides[dep_with_arg] = dep_override_for_dep_with_arg("aaa")
    resp = test_client.get(
        "/a",
    )
    resp_json = resp.json()
    assert resp_json == "aaa"


def test_a_method_4():
    def dep_override_for_dep_with_arg():
        return "aaa"

    test_client = TestClient(app=app)
    test_client.app.dependency_overrides[dep_with_arg] = dep_override_for_dep_with_arg
    resp = test_client.get(
        "/a",
    )
    resp_json = resp.json()
    assert resp_json == "aaa"

test_b 按预期通过,但所有其他测试均失败:

FAILED test.py::test_a_method_1 - AssertionError: assert 'a' == 'aaa'
FAILED test.py::test_a_method_2 - AssertionError: assert 'a' == 'aaa'
FAILED test.py::test_a_method_3 - AssertionError: assert 'a' == 'aaa'
FAILED test.py::test_a_method_4 - AssertionError: assert 'a' == 'aaa'

我应该如何覆盖 dep_with_arg 在上面的例子中?

相关问题: Overriding FastAPI dependencies that have parameters