第 19 章：AI 编码工具链对比与选型

def calculate_total_price(items: list[dict]) -> float:
    # 用户输入注释或函数签名，Copilot 自动补全
    total = sum(item["price"] * item["quantity"] for item in items)
    return round(total, 2)

用户：帮我在项目中添加一个用户认证中间件，要求：
1. 使用 JWT
2. 保护 /api/admin/* 路由
3. 返回 401 时附带 JSON 错误信息

Agent：
- 读取项目结构
- 创建 middleware/auth.ts
- 修改相关路由
- 运行测试
- 报告结果

# 提示：使用 FastAPI 创建一个用户 CRUD 服务，包含 Pydantic schema、SQLAlchemy ORM、pytest 测试
from fastapi import FastAPI, Depends, HTTPException
from sqlalchemy.orm import Session
from . import models, schemas, crud
from .database import SessionLocal

app = FastAPI()

def get_db():
    db = SessionLocal()
    try:
        yield db
    finally:
        db.close()

@app.post("/users/", response_model=schemas.User)
def create_user(user: schemas.UserCreate, db: Session = Depends(get_db)):
    return crud.create_user(db=db, user=user)

// 提示：为订单服务生成 Express 路由，包含参数校验和错误处理
import { Router } from "express";
import { z } from "zod";
import * as orderService from "../services/orderService";

const router = Router();

const createOrderSchema = z.object({
  userId: z.string().uuid(),
  items: z.array(z.object({ productId: z.string(), quantity: z.number().int().positive() })),
});

router.post("/", async (req, res, next) => {
  try {
    const dto = createOrderSchema.parse(req.body);
    const order = await orderService.create(dto);
    res.status(201).json(order);
  } catch (err) {
    next(err);
  }
});

export default router;

package handlers

import (
    "encoding/json"
    "net/http"

    "github.com/example/api/services"
)

type CreateUserRequest struct {
    Email    string `json:"email"`
    Password string `json:"password"`
}

func CreateUser(svc services.UserService) http.HandlerFunc {
    return func(w http.ResponseWriter, r *http.Request) {
        var req CreateUserRequest
        if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
            http.Error(w, err.Error(), http.StatusBadRequest)
            return
        }
        user, err := svc.Create(r.Context(), req.Email, req.Password)
        if err != nil {
            http.Error(w, err.Error(), http.StatusInternalServerError)
            return
        }
        json.NewEncoder(w).Encode(user)
    }
}

package com.example.demo.controller;

import com.example.demo.dto.CreateUserRequest;
import com.example.demo.dto.UserResponse;
import com.example.demo.service.UserService;
import jakarta.validation.Valid;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.*;

@RestController
@RequestMapping("/api/users")
public class UserController {

    private final UserService userService;

    public UserController(UserService userService) {
        this.userService = userService;
    }

    @PostMapping
    public ResponseEntity<UserResponse> createUser(@Valid @RequestBody CreateUserRequest request) {
        var user = userService.create(request);
        return ResponseEntity.ok(user);
    }
}