refactor(utils): 提取 HTTP 错误响应辅助函数

新增 SendError 和 SendErrorWithDetail 函数，统一处理 HTTP 错误响应，减少重复代码。

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

internal/handler/static.go

@@ -28,6 +28,7 @@ import (
 	"github.com/valyala/fasthttp"
 	"rua.plus/lolly/internal/cache"
 	"rua.plus/lolly/internal/middleware/compression"
+	"rua.plus/lolly/internal/utils"
 )
 
 // StaticHandler 静态文件处理器。
@@ -212,7 +213,7 @@ func (h *StaticHandler) Handle(ctx *fasthttp.RequestCtx) {
 
 	// 安全检查：防止目录遍历
 	if strings.Contains(reqPath, "..") {
-		ctx.Error("Forbidden", fasthttp.StatusForbidden)
+		utils.SendError(ctx, utils.ErrForbidden)
 		return
 	}
 
@@ -290,7 +291,7 @@ func (h *StaticHandler) handleTryFiles(ctx *fasthttp.RequestCtx, reqPath string)
 	}
 
 	// 所有 try_files 都未找到
-	ctx.Error("Not Found", fasthttp.StatusNotFound)
+	utils.SendError(ctx, utils.ErrNotFound)
 }
 
 // resolveTryFilePath 解析 try_files 中的占位符。
@@ -369,11 +370,11 @@ func (h *StaticHandler) handleInternalRedirect(ctx *fasthttp.RequestCtx, targetP
 	}
 	info, err := os.Stat(filePath)
 	if err != nil {
-		ctx.Error("Not Found", fasthttp.StatusNotFound)
+		utils.SendError(ctx, utils.ErrNotFound)
 		return
 	}
 	if info.IsDir() {
-		ctx.Error("Forbidden", fasthttp.StatusForbidden)
+		utils.SendError(ctx, utils.ErrForbidden)
 		return
 	}
 	h.serveFile(ctx, filePath, info)
@@ -419,7 +420,7 @@ func (h *StaticHandler) handleStandard(ctx *fasthttp.RequestCtx, reqPath string)
 	// 检查文件/目录是否存在
 	info, err := os.Stat(filePath)
 	if err != nil {
-		ctx.Error("Not Found", fasthttp.StatusNotFound)
+		utils.SendError(ctx, utils.ErrNotFound)
 		return
 	}
 
@@ -432,7 +433,7 @@ func (h *StaticHandler) handleStandard(ctx *fasthttp.RequestCtx, reqPath string)
 				return
 			}
 		}
-		ctx.Error("Forbidden", fasthttp.StatusForbidden)
+		utils.SendError(ctx, utils.ErrForbidden)
 		return
 	}
 
@@ -492,7 +493,7 @@ func (h *StaticHandler) serveFile(ctx *fasthttp.RequestCtx, filePath string, inf
 	// 读取文件内容
 	data, err := os.ReadFile(filePath)
 	if err != nil {
-		ctx.Error("Internal Server Error", fasthttp.StatusInternalServerError)
+		utils.SendError(ctx, utils.ErrInternalError)
 		return
 	}
 

internal/middleware/security/ratelimit.go

@@ -40,6 +40,7 @@ import (
 	"rua.plus/lolly/internal/config"
 	"rua.plus/lolly/internal/middleware"
 	"rua.plus/lolly/internal/netutil"
+	"rua.plus/lolly/internal/utils"
 )
 
 const rateLimitHeader = "header"
@@ -174,7 +175,7 @@ func (s *SlidingWindowLimiterWrapper) Process(next fasthttp.RequestHandler) fast
 		key := s.keyFunc(ctx)
 
 		if !s.limiter.Allow(key) {
-			ctx.Error("Too Many Requests", fasthttp.StatusTooManyRequests)
+			utils.SendError(ctx, utils.ErrTooManyRequests)
 			return
 		}
 
@@ -208,7 +209,7 @@ func (rl *RateLimiter) Process(next fasthttp.RequestHandler) fasthttp.RequestHan
 			// 计算重试等待时间
 			retryAfter := rl.getRetryAfter(key)
 			ctx.Response.Header.Set("Retry-After", fmt.Sprintf("%d", retryAfter))
-			ctx.Error("Too Many Requests", fasthttp.StatusTooManyRequests)
+			utils.SendError(ctx, utils.ErrTooManyRequests)
 			return
 		}
 
@@ -615,7 +616,7 @@ func (m *connLimiterMiddleware) Name() string {
 func (m *connLimiterMiddleware) Process(next fasthttp.RequestHandler) fasthttp.RequestHandler {
 	return func(ctx *fasthttp.RequestCtx) {
 		if !m.limiter.Acquire(ctx) {
-			ctx.Error("Service Unavailable: Connection limit exceeded", fasthttp.StatusServiceUnavailable)
+			utils.SendErrorWithDetail(ctx, utils.ErrServiceUnavailable, "Connection limit exceeded")
 			return
 		}
 

internal/proxy/proxy.go

@@ -48,6 +48,7 @@ import (
 	"rua.plus/lolly/internal/logging"
 	"rua.plus/lolly/internal/netutil"
 	"rua.plus/lolly/internal/resolver"
+	"rua.plus/lolly/internal/utils"
 	"rua.plus/lolly/internal/variable"
 )
 
@@ -337,7 +338,7 @@ func (p *Proxy) ServeHTTP(ctx *fasthttp.RequestCtx) {
 				// 没有可用后端
 				upstreamAddr = "FAILED"
 				upstreamStatus = 502
-				ctx.Error("Bad Gateway: no healthy upstream", fasthttp.StatusBadGateway)
+				utils.SendErrorWithDetail(ctx, utils.ErrBadGateway, "no healthy upstream")
 				return
 			}
 			// 没有更多可用目标，返回最后一次错误
@@ -522,18 +523,18 @@ func (p *Proxy) ServeHTTP(ctx *fasthttp.RequestCtx) {
 		// 处理不同类型的错误
 		if errors.Is(lastErr, fasthttp.ErrTimeout) {
 			upstreamStatus = 504
-			ctx.Error("Gateway Timeout", fasthttp.StatusGatewayTimeout)
+			utils.SendError(ctx, utils.ErrGatewayTimeout)
 		} else if errors.Is(lastErr, fasthttp.ErrConnectionClosed) {
 			upstreamStatus = 502
-			ctx.Error("Bad Gateway: upstream connection closed", fasthttp.StatusBadGateway)
+			utils.SendErrorWithDetail(ctx, utils.ErrBadGateway, "upstream connection closed")
 		} else {
 			upstreamStatus = 502
-			ctx.Error("Bad Gateway", fasthttp.StatusBadGateway)
+			utils.SendError(ctx, utils.ErrBadGateway)
 		}
 	} else {
 		upstreamAddr = "FAILED"
 		upstreamStatus = 502
-		ctx.Error("Bad Gateway: all upstreams failed", fasthttp.StatusBadGateway)
+		utils.SendErrorWithDetail(ctx, utils.ErrBadGateway, "all upstreams failed")
 	}
 }
 

internal/server/status.go

@@ -22,6 +22,7 @@ import (
 	"github.com/valyala/fasthttp"
 	"rua.plus/lolly/internal/config"
 	"rua.plus/lolly/internal/netutil"
+	"rua.plus/lolly/internal/utils"
 )
 
 // StatusHandler 状态监控处理器。
@@ -182,7 +183,7 @@ func (h *StatusHandler) Path() string {
 func (h *StatusHandler) ServeHTTP(ctx *fasthttp.RequestCtx) {
 	// 步骤1: 检查 IP 访问权限
 	if !h.checkAccess(ctx) {
-		ctx.Error("Forbidden: Access denied", fasthttp.StatusForbidden)
+		utils.SendErrorWithDetail(ctx, utils.ErrForbidden, "Access denied")
 		return
 	}
 
@@ -201,7 +202,7 @@ func (h *StatusHandler) ServeHTTP(ctx *fasthttp.RequestCtx) {
 
 	data, err := json.MarshalIndent(status, "", "  ")
 	if err != nil {
-		ctx.Error("Internal Server Error", fasthttp.StatusInternalServerError)
+		utils.SendError(ctx, utils.ErrInternalError)
 		return
 	}
 

internal/utils/httperror.go

@@ -0,0 +1,39 @@
+// Package utils provides utility functions for HTTP error handling.
+//
+// This file implements a unified HTTP error response helper to reduce
+// the scattered pattern of ctx.Error throughout the codebase.
+package utils
+
+import "github.com/valyala/fasthttp"
+
+// HTTPError represents an HTTP error with a message and status code.
+type HTTPError struct {
+	Message    string
+	StatusCode int
+}
+
+// Predefined common HTTP errors.
+var (
+	ErrNotFound            = HTTPError{Message: "Not Found", StatusCode: fasthttp.StatusNotFound}
+	ErrForbidden           = HTTPError{Message: "Forbidden", StatusCode: fasthttp.StatusForbidden}
+	ErrUnauthorized        = HTTPError{Message: "Unauthorized", StatusCode: fasthttp.StatusUnauthorized}
+	ErrBadGateway          = HTTPError{Message: "Bad Gateway", StatusCode: fasthttp.StatusBadGateway}
+	ErrGatewayTimeout      = HTTPError{Message: "Gateway Timeout", StatusCode: fasthttp.StatusGatewayTimeout}
+	ErrInternalError       = HTTPError{Message: "Internal Server Error", StatusCode: fasthttp.StatusInternalServerError}
+	ErrTooManyRequests     = HTTPError{Message: "Too Many Requests", StatusCode: fasthttp.StatusTooManyRequests}
+	ErrServiceUnavailable  = HTTPError{Message: "Service Unavailable", StatusCode: fasthttp.StatusServiceUnavailable}
+)
+
+// SendError sends an HTTP error response to the client.
+func SendError(ctx *fasthttp.RequestCtx, err HTTPError) {
+	ctx.Error(err.Message, err.StatusCode)
+}
+
+// SendErrorWithDetail sends an HTTP error response with additional detail.
+func SendErrorWithDetail(ctx *fasthttp.RequestCtx, err HTTPError, detail string) {
+	if detail != "" {
+		ctx.Error(err.Message+": "+detail, err.StatusCode)
+	} else {
+		SendError(ctx, err)
+	}
+}