from typing import Annotated import pytest from dirty_equals import IsPartialDict from fastapi import Cookie, FastAPI, Header, Query from fastapi._compat import PYDANTIC_VERSION_MINOR_TUPLE from fastapi.testclient import TestClient from inline_snapshot import snapshot from pydantic import BaseModel, ConfigDict, Field app = FastAPI() class Model(BaseModel): param: str = Field(alias="param_alias") @app.get("/query") async def query_model(data: Model = Query()): return {"param": data.param} @app.get("/header") async def header_model(data: Model = Header()): return {"param": data.param} @app.get("/cookie") async def cookie_model(data: Model = Cookie()): return {"param": data.param} def test_query_model_with_alias(): client = TestClient(app) response = client.get("/query", params={"param_alias": "value"}) assert response.status_code == 200, response.text assert response.json() == {"param": "value"} def test_header_model_with_alias(): client = TestClient(app) response = client.get("/header", headers={"param_alias": "value"}) assert response.status_code == 200, response.text assert response.json() == {"param": "value"} def test_cookie_model_with_alias(): client = TestClient(app) client.cookies.set("param_alias", "value") response = client.get("/cookie") assert response.status_code == 200, response.text assert response.json() == {"param": "value"} def test_query_model_with_alias_by_name(): client = TestClient(app) response = client.get("/query", params={"param": "value"}) assert response.status_code == 422, response.text details = response.json() assert details["detail"][0]["input"] == {"param": "value"} def test_header_model_with_alias_by_name(): client = TestClient(app) response = client.get("/header", headers={"param": "value"}) assert response.status_code == 422, response.text details = response.json() assert details["detail"][0]["input"] == IsPartialDict({"param": "value"}) def test_cookie_model_with_alias_by_name(): client = TestClient(app) client.cookies.set("param", "value") response = client.get("/cookie") assert response.status_code == 422, response.text details = response.json() assert details["detail"][0]["input"] == {"param": "value"} @pytest.mark.skipif( PYDANTIC_VERSION_MINOR_TUPLE < (2, 11), reason="validate_by_alias requires Pydantic 2.11", ) def test_openapi_with_validation_by_alias_disabled(): app = FastAPI() class Model(BaseModel): model_config = ConfigDict(validate_by_alias=False) int_value: Annotated[int, Field(alias="legacy")] @app.get("/query") def read_query(data: Annotated[Model, Query()]): return data @app.get("/header") def read_header(data: Annotated[Model, Header()]): return data @app.get("/cookie") def read_cookie(data: Annotated[Model, Cookie()]): return data client = TestClient(app) response = client.get("/query", params={"int_value": "1"}) assert response.status_code == 200 assert response.json() == {"legacy": 1} response = client.get("/header", headers={"int-value": "1"}) assert response.status_code == 200 assert response.json() == {"legacy": 1} response = client.get("/cookie", headers={"cookie": "int_value=1"}) assert response.status_code == 200 assert response.json() == {"legacy": 1} response = client.get("/openapi.json") assert response.status_code == 200 assert response.json() == snapshot( { "openapi": "3.1.0", "info": {"title": "FastAPI", "version": "0.1.0"}, "paths": { "/query": { "get": { "summary": "Read Query", "operationId": "read_query_query_get", "parameters": [ { "name": "int_value", "in": "query", "required": True, "schema": {"type": "integer", "title": "Int Value"}, } ], "responses": { "200": { "description": "Successful Response", "content": {"application/json": {"schema": {}}}, }, "422": { "description": "Validation Error", "content": { "application/json": { "schema": { "$ref": "#/components/schemas/HTTPValidationError" } } }, }, }, } }, "/header": { "get": { "summary": "Read Header", "operationId": "read_header_header_get", "parameters": [ { "name": "int-value", "in": "header", "required": True, "schema": {"type": "integer", "title": "Int Value"}, } ], "responses": { "200": { "description": "Successful Response", "content": {"application/json": {"schema": {}}}, }, "422": { "description": "Validation Error", "content": { "application/json": { "schema": { "$ref": "#/components/schemas/HTTPValidationError" } } }, }, }, } }, "/cookie": { "get": { "summary": "Read Cookie", "operationId": "read_cookie_cookie_get", "parameters": [ { "name": "int_value", "in": "cookie", "required": True, "schema": {"type": "integer", "title": "Int Value"}, } ], "responses": { "200": { "description": "Successful Response", "content": {"application/json": {"schema": {}}}, }, "422": { "description": "Validation Error", "content": { "application/json": { "schema": { "$ref": "#/components/schemas/HTTPValidationError" } } }, }, }, } }, }, "components": { "schemas": { "HTTPValidationError": { "properties": { "detail": { "items": { "$ref": "#/components/schemas/ValidationError" }, "type": "array", "title": "Detail", } }, "type": "object", "title": "HTTPValidationError", }, "ValidationError": { "properties": { "loc": { "items": { "anyOf": [{"type": "string"}, {"type": "integer"}] }, "type": "array", "title": "Location", }, "msg": {"type": "string", "title": "Message"}, "type": {"type": "string", "title": "Error Type"}, "input": {"title": "Input"}, "ctx": {"type": "object", "title": "Context"}, }, "type": "object", "required": ["loc", "msg", "type"], "title": "ValidationError", }, } }, } )