from typing import Awaitable, Callable, List from unittest.mock import ANY from fastapi import Body, Depends, FastAPI from fastapi.testclient import TestClient app = FastAPI() def make_field(name: str) -> Callable[..., Awaitable[str]]: async def inner(value: str = Body(..., alias=name)) -> str: return value return inner @app.post("/example") def example( field_0: str = Body(...), field_1_: str = Body(..., alias="field_1"), field_2_: str = Depends(make_field("field_2")), field_3_: str = Depends(make_field("field_3")), ) -> List[str]: return [field_0, field_1_, field_2_, field_3_] openapi_schema = { "openapi": "3.1.0", "info": {"title": "FastAPI", "version": "0.1.0"}, "paths": { "/example": { "post": { "summary": "Example", "operationId": "example_example_post", "requestBody": { "content": { "application/json": { "schema": { "$ref": "#/components/schemas/Body_example_example_post" } } }, "required": True, }, "responses": { "200": { "description": "Successful Response", "content": { "application/json": { "schema": { "title": "Response Example Example Post", "type": "array", "items": {"type": "string"}, } } }, }, "422": ANY, }, } } }, "components": { "schemas": { "Body_example_example_post": { "title": "Body_example_example_post", "type": "object", "properties": { "field_0": {"title": "Field 0", "type": "string"}, "field_1": {"title": "Field 1", "type": "string"}, "field_2": {"title": "Field 2", "type": "string"}, "field_3": {"title": "Field 3", "type": "string"}, }, "required": ["field_0", "field_1", "field_2", "field_3"], }, "HTTPValidationError": ANY, "ValidationError": ANY, } }, } client = TestClient(app) def test_openapi_schema(): response = client.get("/openapi.json") assert response.status_code == 200, response.text assert response.json() == openapi_schema def test_valid(): response = client.post( "/example/", json={"field_0": "a", "field_1": "b", "field_2": "c", "field_3": "d"}, ) assert response.status_code == 200, response.text assert response.json() == ["a", "b", "c", "d"] def test_missing(): response = client.post("/example/", json={}) assert response.status_code == 422, response.text resp_json = response.json() assert len(resp_json["detail"]) == 4 assert resp_json["detail"][0]["loc"] == ["body", "field_2"] assert str(resp_json["detail"][0]["msg"]).lower() == "field required" assert resp_json["detail"][1]["loc"] == ["body", "field_3"] assert str(resp_json["detail"][1]["msg"]).lower() == "field required" assert resp_json["detail"][2]["loc"] == ["body", "field_0"] assert str(resp_json["detail"][2]["msg"]).lower() == "field required" assert resp_json["detail"][3]["loc"] == ["body", "field_1"] assert str(resp_json["detail"][3]["msg"]).lower() == "field required"