前端本地开发提效：用 Go 搞一个轻量级 HTTPS 本地代理与 Mock 服务

package main

import (
    "log"
    "net/http"
)

func startServer(handler http.Handler) {
    certFile := "./certs/local.dev.com.pem"
    keyFile := "./certs/local.dev.com-key.pem"

    server := &http.Server{
        Addr:    ":443",
        Handler: handler,
    }

    log.Println("Dev Proxy running at https://local.dev.com")
    if err := server.ListenAndServeTLS(certFile, keyFile); err != nil {
        log.Fatalf("HTTPS Server failed: %v", err)
    }
}

package main

import (
    "io"
    "net/http"
    "os"
    "path/filepath"
    "strings"
)

func tryServeMock(w http.ResponseWriter, r *http.Request) bool {
    // 构建对应的本地文件路径
    // 比如 mocks/GET/api/user.json
    cleanPath := filepath.Clean(r.URL.Path)
    mockPath := filepath.Join("mocks", r.Method, cleanPath+".json")

    fileInfo, err := os.Stat(mockPath)
    if err != nil || fileInfo.IsDir() {
        return false // 文件不存在，跳过 Mock
    }

    data, err := os.ReadFile(mockPath)
    if err != nil {
        http.Error(w, "Failed to read mock file", http.StatusInternalServerError)
        return true
    }

    // 设置标准的 JSON 响应头，并解决本地跨域问题
    w.Header().Set("Content-Type", "application/json; charset=utf-8")
    w.Header().Set("Access-Control-Allow-Origin", "*")
    w.Header().Set("Access-Control-Allow-Methods", "GET, POST, PUT, DELETE, OPTIONS")
    w.Header().Set("Access-Control-Allow-Headers", "*")
    w.WriteHeader(http.StatusOK)
    w.Write(data)

    return true
}

package main

import (
    "net/http"
    "net/http/httputil"
    "net/url"
)

type DevProxyHandler struct {
    targetProxy *httputil.ReverseProxy
}

func NewDevProxyHandler(targetURL string) *DevProxyHandler {
    target, _ := url.Parse(targetURL)
    proxy := httputil.NewSingleHostReverseProxy(target)

    // 自定义 Director 处理 Host 头，避免开发服务器 Host 校验报错
    originalDirector := proxy.Director
    proxy.Director = func(req *http.Request) {
        originalDirector(req)
        req.Host = target.Host
    }

    return &DevProxyHandler{
        targetProxy: proxy,
    }
}

func (h *DevProxyHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
    // 1. 处理预检请求 (CORS OPTIONS)
    if r.Method == http.MethodOptions {
        w.Header().Set("Access-Control-Allow-Origin", "*")
        w.Header().Set("Access-Control-Allow-Methods", "GET, POST, PUT, DELETE, OPTIONS")
        w.Header().Set("Access-Control-Allow-Headers", "*")
        w.WriteHeader(http.StatusNoContent)
        return
    }

    // 2. 尝试命中 Mock
    if tryServeMock(w, r) {
        return
    }

    // 3. 没命中，转发给本地 Vite 服务 (如 http://localhost:5173)
    h.targetProxy.ServeHTTP(w, r)
}

package main

func main() {
    // 目标开发服务器地址，也可以通过 flag 传入
    viteServer := "http://localhost:5173"
    
    handler := NewDevProxyHandler(viteServer)
    startServer(handler)
}