FastAPI 的單元測試
- 對於服務端來說,通常會對功能進行單元測試,也稱白盒測試
- FastAPI 整合了第三方庫,讓我們可以快捷的編寫單元測試
- FastAPI 的單元測試是基於 Pytest + Request 的
Pytest 學習
https://www.cnblogs.com/poloyy/tag/Pytest/
TestClient 簡單的栗子
#!usr/bin/env python # -*- coding:utf-8 _*- """ # author: 小菠蘿測試筆記 # blog: https://www.cnblogs.com/poloyy/ # time: 2021/9/29 10:55 下午 # file: 37_pytest.py """ import uvicorn from fastapi import FastAPI from fastapi.testclient import TestClient app = FastAPI() @app.get("/") async def read_main(): return {"msg": "Hello World"} # 宣告一個 TestClient,把 FastAPI() 例項物件傳進去 client = TestClient(app) # 測試用 def test_read_main(): # 請求 127.0.0.1:8080/ response = client.get("/") assert response.status_code == 200 assert response.json() == {"msg": "Hello World"} if __name__ == '__main__': uvicorn.run(app="37_pytest:app", reload=True, host="127.0.0.1", port=8080)
在該資料夾下的命令列敲
pytest 37_pytest.py
執行結果
TestClient 的原始碼解析
繼承了 requests 庫的 Session
所以可以像使用 requests 庫一樣使用 TestClient,擁有 requests 所有方法、屬性
重寫了 Session.requests 方法
重寫了 requests 方法,不過只是加了一句 url = urljoin(self.base_url, url) url 拼接程式碼,還有給函式引數都加了型別指示,更加完善啦~
自定義 websocket 連線方法
後面學到 webSocket 再詳細講他
重寫了 __enter__、__exit__ 方法
- Session 的這兩個方法還是比較簡陋的,TestClient 做了一次重寫,主要是為了新增非同步的功能(非同步測試後面詳解,這篇舉栗子的都是普通函式 def)
- 前面講過有 __enter__、__exit__ 方法的物件都是上下文管理器,可以用 with .. as .. 語句來呼叫上下文管理器哦
.get() 方法
上面程式碼 client.get(),直接呼叫的就是 Session 提供的 get() 方法啦!
複雜的測試場景
服務端
#!usr/bin/env python # -*- coding:utf-8 _*- """ # author: 小菠蘿測試筆記 # blog: https://www.cnblogs.com/poloyy/ # time: 2021/9/29 10:55 下午 # file: s37_pytest.py """ import uvicorn from fastapi import FastAPI from fastapi.testclient import TestClient app = FastAPI() @app.get("/") async def read_main(): return {"msg": "Hello World"} # 宣告一個 TestClient,把 FastAPI() 例項物件傳進去 client = TestClient(app) # 測試用 def test_read_main(): # 請求 127.0.0.1:8080/ response = client.get("/") assert response.status_code == 200 assert response.json() == {"msg": "Hello World"} from typing import Optional from fastapi import FastAPI, Header, HTTPException from pydantic import BaseModel # 模擬真實 token fake_secret_token = "coneofsilence" # 模擬真實資料庫 fake_db = { "foo": {"id": "foo", "title": "Foo", "description": "There goes my hero"}, "bar": {"id": "bar", "title": "Bar", "description": "The bartenders"}, } app = FastAPI() class Item(BaseModel): id: str title: str description: Optional[str] = None # 介面一:查詢資料 @app.get("/items/{item_id}", response_model=Item) async def read_main(item_id: str, x_token: str = Header(...)): # 1、校驗 token 失敗 if x_token != fake_secret_token: raise HTTPException(status_code=400, detail="x-token 錯誤") # 2、若資料庫沒有對應資料 if item_id not in fake_db: raise HTTPException(status_code=404, detail="找不到 item_id") # 3、找到資料則返回 return fake_db[item_id] # 介面二:建立資料 @app.post("/items/", response_model=Item) async def create_item(item: Item, x_token: str = Header(...)): # 1、校驗 token 失敗 if x_token != fake_secret_token: raise HTTPException(status_code=400, detail="x-token 錯誤") # 2、若資料庫已經存在相同 id 的資料 if item.id in fake_db: raise HTTPException(status_code=400, detail="找不到 item_id") # 3、新增資料到資料庫 fake_db[item.id] = item # 4、返回新增的資料 return item if __name__ == '__main__': uvicorn.run(app="s37_test_pytest:app", reload=True, host="127.0.0.1", port=8080)
單元測試
#!usr/bin/env python # -*- coding:utf-8 _*- """ # author: 小菠蘿測試筆記 # blog: https://www.cnblogs.com/poloyy/ # time: 2021/9/29 10:55 下午 # file: s37_pytest.py """ from fastapi.testclient import TestClient from .s37_test_pytest import app client = TestClient(app) def test_read_item(): expect = {"id": "foo", "title": "Foo", "description": "There goes my hero"} headers = {"x-token": "coneofsilence"} resp = client.get("/items/foo", headers=headers) assert resp.status_code == 200 assert resp.json() == expect def test_read_item_error_header(): expect = {"detail": "x-token 錯誤"} headers = {"x-token": "test"} resp = client.get("/items/foo", headers=headers) assert resp.status_code == 400 assert resp.json() == expect def test_read_item_error_id(): expect = {"detail": "找不到 item_id"} headers = {"x-token": "coneofsilence"} resp = client.get("/items/foos", headers=headers) assert resp.status_code == 404 assert resp.json() == expect def test_create_item(): body = {"id": "foos", "title": "Foo", "description": "There goes my hero"} headers = {"x-token": "coneofsilence"} resp = client.post("/items/", json=body, headers=headers) assert resp.status_code == 200 assert resp.json() == body def test_create_item_error_header(): body = {"id": "foo", "title": "Foo", "description": "There goes my hero"} expect = {"detail": "x-token 錯誤"} headers = {"x-token": "test"} resp = client.post("/items/", json=body, headers=headers) assert resp.status_code == 400 assert resp.json() == expect def test_create_item_error_id(): expect = {"detail": "找不到 item_id"} body = {"id": "foo", "title": "Foo", "description": "There goes my hero"} headers = {"x-token": "coneofsilence"} resp = client.post("/items/", json=body, headers=headers) assert resp.status_code == 400 assert resp.json() == expect
命令列執行
pytest test.py -sq
執行結果
> pytest s37_pytest.py -sq ...... 6 passed in 0.40s