refactor(proxy): 提取命名常量并适配变量系统重命名

提取硬编码字符串为命名常量：
- upstreamCache = "CACHE"
- protoHTTPS = "https"
ProxyWebSocket → WebSocket
适配 variable.Context 重命名

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

internal/proxy/health.go

@@ -25,6 +25,8 @@ import (
 	"rua.plus/lolly/internal/loadbalance"
 )
 
+const healthPath = "/health"
+
 // HealthChecker 对后端目标执行健康检查。
 // 它支持主动（定期 HTTP 探测）和被动（基于失败的）
 // 两种健康检查模式。
@@ -97,7 +99,7 @@ func NewHealthChecker(targets []*loadbalance.Target, cfg *config.HealthCheckConf
 
 	path := cfg.Path
 	if path == "" {
-		path = "/health"
+		path = healthPath
 	}
 
 	return &HealthChecker{

internal/proxy/health_test.go

@@ -42,8 +42,8 @@ func TestNewHealthChecker(t *testing.T) {
 		if checker.GetTimeout() != 5*time.Second {
 			t.Errorf("Timeout = %v, want %v", checker.GetTimeout(), 5*time.Second)
 		}
-		if checker.GetPath() != "/health" {
+		if checker.GetPath() != healthPath {
-			t.Errorf("Path = %q, want %q", checker.GetPath(), "/health")
+			t.Errorf("Path = %q, want %q", checker.GetPath(), healthPath)
 		}
 		if checker.IsRunning() {
 			t.Error("新建的 checker 应未启动")
@@ -115,7 +115,7 @@ func TestNewHealthChecker(t *testing.T) {
 		if checker.GetTimeout() != 5*time.Second {
 			t.Errorf("零值 Timeout 应使用默认值，got %v", checker.GetTimeout())
 		}
-		if checker.GetPath() != "/health" {
+		if checker.GetPath() != healthPath {
 			t.Errorf("空 Path 应使用默认值，got %q", checker.GetPath())
 		}
 	})
@@ -131,7 +131,7 @@ func TestHealthCheckerStartStop(t *testing.T) {
 		cfg := &config.HealthCheckConfig{
 			Interval: 1 * time.Hour,
 			Timeout:  5 * time.Second,
-			Path:     "/health",
+			Path:     healthPath,
 		}
 
 		checker := NewHealthChecker(targets, cfg)
@@ -200,8 +200,8 @@ func TestHealthCheckerStartStop(t *testing.T) {
 func TestCheckTarget(t *testing.T) {
 	t.Run("健康响应", func(t *testing.T) {
 		server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-			if r.URL.Path != "/health" {
+			if r.URL.Path != healthPath {
-				t.Errorf("请求路径 = %q, want %q", r.URL.Path, "/health")
+				t.Errorf("请求路径 = %q, want %q", r.URL.Path, healthPath)
 			}
 			w.WriteHeader(http.StatusOK)
 		}))
@@ -215,7 +215,7 @@ func TestCheckTarget(t *testing.T) {
 		checker := NewHealthChecker([]*loadbalance.Target{target}, &config.HealthCheckConfig{
 			Interval: 1 * time.Hour,
 			Timeout:  5 * time.Second,
-			Path:     "/health",
+			Path:     healthPath,
 		})
 
 		checker.checkTarget(target)
@@ -226,7 +226,7 @@ func TestCheckTarget(t *testing.T) {
 	})
 
 	t.Run("不健康响应", func(t *testing.T) {
-		server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
 			w.WriteHeader(http.StatusInternalServerError)
 		}))
 		defer server.Close()
@@ -239,7 +239,7 @@ func TestCheckTarget(t *testing.T) {
 		checker := NewHealthChecker([]*loadbalance.Target{target}, &config.HealthCheckConfig{
 			Interval: 1 * time.Hour,
 			Timeout:  5 * time.Second,
-			Path:     "/health",
+			Path:     healthPath,
 		})
 
 		checker.checkTarget(target)
@@ -250,7 +250,7 @@ func TestCheckTarget(t *testing.T) {
 	})
 
 	t.Run("超时", func(t *testing.T) {
-		server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		server := httptest.NewServer(http.HandlerFunc(func(_ http.ResponseWriter, _ *http.Request) {
 			time.Sleep(100 * time.Millisecond)
 		}))
 		defer server.Close()
@@ -263,7 +263,7 @@ func TestCheckTarget(t *testing.T) {
 		checker := NewHealthChecker([]*loadbalance.Target{target}, &config.HealthCheckConfig{
 			Interval: 1 * time.Hour,
 			Timeout:  10 * time.Millisecond,
-			Path:     "/health",
+			Path:     healthPath,
 		})
 
 		checker.checkTarget(target)
@@ -282,7 +282,7 @@ func TestCheckTarget(t *testing.T) {
 		checker := NewHealthChecker([]*loadbalance.Target{target}, &config.HealthCheckConfig{
 			Interval: 1 * time.Hour,
 			Timeout:  100 * time.Millisecond,
-			Path:     "/health",
+			Path:     healthPath,
 		})
 
 		checker.checkTarget(target)
@@ -293,7 +293,7 @@ func TestCheckTarget(t *testing.T) {
 	})
 
 	t.Run("3xx 重定向响应", func(t *testing.T) {
-		server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
 			w.WriteHeader(http.StatusMovedPermanently)
 		}))
 		defer server.Close()
@@ -306,7 +306,7 @@ func TestCheckTarget(t *testing.T) {
 		checker := NewHealthChecker([]*loadbalance.Target{target}, &config.HealthCheckConfig{
 			Interval: 1 * time.Hour,
 			Timeout:  5 * time.Second,
-			Path:     "/health",
+			Path:     healthPath,
 		})
 
 		checker.checkTarget(target)
@@ -317,7 +317,7 @@ func TestCheckTarget(t *testing.T) {
 	})
 
 	t.Run("4xx 客户端错误响应", func(t *testing.T) {
-		server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
 			w.WriteHeader(http.StatusNotFound)
 		}))
 		defer server.Close()
@@ -330,7 +330,7 @@ func TestCheckTarget(t *testing.T) {
 		checker := NewHealthChecker([]*loadbalance.Target{target}, &config.HealthCheckConfig{
 			Interval: 1 * time.Hour,
 			Timeout:  5 * time.Second,
-			Path:     "/health",
+			Path:     healthPath,
 		})
 
 		checker.checkTarget(target)
@@ -352,7 +352,7 @@ func TestCheckTarget(t *testing.T) {
 
 		for _, tt := range tests {
 			t.Run(tt.name, func(t *testing.T) {
-				server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+				server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
 					w.WriteHeader(tt.statusCode)
 				}))
 				defer server.Close()
@@ -365,7 +365,7 @@ func TestCheckTarget(t *testing.T) {
 				checker := NewHealthChecker([]*loadbalance.Target{target}, &config.HealthCheckConfig{
 					Interval: 1 * time.Hour,
 					Timeout:  5 * time.Second,
-					Path:     "/health",
+					Path:     healthPath,
 				})
 
 				checker.checkTarget(target)
@@ -389,7 +389,7 @@ func TestMarkUnhealthy(t *testing.T) {
 		checker := NewHealthChecker([]*loadbalance.Target{target}, &config.HealthCheckConfig{
 			Interval: 1 * time.Hour,
 			Timeout:  5 * time.Second,
-			Path:     "/health",
+			Path:     healthPath,
 		})
 
 		checker.MarkUnhealthy(target)
@@ -408,7 +408,7 @@ func TestMarkUnhealthy(t *testing.T) {
 		checker := NewHealthChecker([]*loadbalance.Target{target}, &config.HealthCheckConfig{
 			Interval: 1 * time.Hour,
 			Timeout:  5 * time.Second,
-			Path:     "/health",
+			Path:     healthPath,
 		})
 
 		checker.MarkUnhealthy(target)
@@ -431,7 +431,7 @@ func TestMarkUnhealthy(t *testing.T) {
 		checker := NewHealthChecker([]*loadbalance.Target{target1, target2}, &config.HealthCheckConfig{
 			Interval: 1 * time.Hour,
 			Timeout:  5 * time.Second,
-			Path:     "/health",
+			Path:     healthPath,
 		})
 
 		checker.MarkUnhealthy(target1)

internal/proxy/proxy.go

@@ -51,6 +51,11 @@ import (
 	"rua.plus/lolly/internal/variable"
 )
 
+const (
+	upstreamCache = "CACHE"
+	protoHTTPS    = "https"
+)
+
 // Proxy 表示反向代理实例，负责将 HTTP 请求转发到后端目标。
 //
 // 它为每个后端目标管理连接池，并提供负载均衡功能。
@@ -272,9 +277,9 @@ func (t *UpstreamTiming) GetResponseTime() float64 {
 	return t.responseEnd.Sub(t.connectEnd).Seconds()
 }
 
-// FinalizeUpstreamVars 在请求处理结束时设置上游变量到 VariableContext
+// FinalizeUpstreamVars 在请求处理结束时设置上游变量到 Context
 // 这个函数应该在 ServeHTTP 的 defer 中调用
-func FinalizeUpstreamVars(vc *variable.VariableContext, upstreamAddr string, upstreamStatus int, timing *UpstreamTiming) {
+func FinalizeUpstreamVars(vc *variable.Context, upstreamAddr string, upstreamStatus int, timing *UpstreamTiming) {
 	if vc == nil {
 		return
 	}
@@ -304,7 +309,7 @@ func (p *Proxy) ServeHTTP(ctx *fasthttp.RequestCtx) {
 	timing := NewUpstreamTiming()
 
 	// 创建变量上下文用于设置上游变量
-	vc := variable.NewVariableContext(ctx)
+	vc := variable.NewContext(ctx)
 	defer func() {
 		// 确保记录了响应结束时间
 		if timing.responseEnd.IsZero() {
@@ -313,7 +318,7 @@ func (p *Proxy) ServeHTTP(ctx *fasthttp.RequestCtx) {
 		// 设置上游变量
 		FinalizeUpstreamVars(vc, upstreamAddr, upstreamStatus, timing)
 		// 释放变量上下文
-		variable.ReleaseVariableContext(vc)
+		variable.ReleaseContext(vc)
 	}()
 
 	// 故障转移配置
@@ -376,7 +381,7 @@ func (p *Proxy) ServeHTTP(ctx *fasthttp.RequestCtx) {
 			// WebSocket 使用 defer 确保连接计数释放
 			defer loadbalance.DecrementConnections(target)
 			timing.MarkConnectStart()
-			err := ProxyWebSocket(ctx, target, p.config.Timeout.Connect)
+			err := WebSocket(ctx, target, p.config.Timeout.Connect)
 			timing.MarkConnectEnd()
 			if err != nil {
 				upstreamStatus = 502
@@ -402,7 +407,7 @@ func (p *Proxy) ServeHTTP(ctx *fasthttp.RequestCtx) {
 				loadbalance.DecrementConnections(target)
 				if !stale {
 					// 新鲜缓存，直接返回
-					upstreamAddr = "CACHE"
+					upstreamAddr = upstreamCache
 					upstreamStatus = entry.Status
 					p.writeCachedResponse(ctx, entry)
 					return
@@ -425,7 +430,7 @@ func (p *Proxy) ServeHTTP(ctx *fasthttp.RequestCtx) {
 				// 重新尝试获取缓存
 
 				if entry, ok, _ := p.cache.Get(hashKey, origKey); ok {
-					upstreamAddr = "CACHE"
+					upstreamAddr = upstreamCache
 					upstreamStatus = entry.Status
 
 					p.writeCachedResponse(ctx, entry)
@@ -634,7 +639,7 @@ func (p *Proxy) getClient(targetURL string) *fasthttp.HostClient {
 
 // modifyRequestHeaders 在转发到后端之前修改请求头。
 // 添加标准代理请求头并应用自定义请求头配置。
-func (p *Proxy) modifyRequestHeaders(ctx *fasthttp.RequestCtx, target *loadbalance.Target) {
+func (p *Proxy) modifyRequestHeaders(ctx *fasthttp.RequestCtx, _ *loadbalance.Target) {
 	headers := &ctx.Request.Header
 
 	// 添加 X-Real-IP 请求头
@@ -660,14 +665,14 @@ func (p *Proxy) modifyRequestHeaders(ctx *fasthttp.RequestCtx, target *loadbalan
 	// 添加 X-Forwarded-Proto 请求头
 	proto := "http"
 	if ctx.IsTLS() {
-		proto = "https"
+		proto = protoHTTPS
 	}
 	headers.Set("X-Forwarded-Proto", proto)
 
 	// 从配置设置自定义请求头（支持变量展开）
 	if p.config.Headers.SetRequest != nil {
-		vc := variable.NewVariableContext(ctx)
+		vc := variable.NewContext(ctx)
-		defer variable.ReleaseVariableContext(vc)
+		defer variable.ReleaseContext(vc)
 		for key, value := range p.config.Headers.SetRequest {
 			expanded := vc.Expand(value)
 			headers.Set(key, expanded)
@@ -686,8 +691,8 @@ func (p *Proxy) modifyRequestHeaders(ctx *fasthttp.RequestCtx, target *loadbalan
 func (p *Proxy) modifyResponseHeaders(ctx *fasthttp.RequestCtx) {
 	// 从配置设置自定义响应头（支持变量展开）
 	if p.config.Headers.SetResponse != nil {
-		vc := variable.NewVariableContext(ctx)
+		vc := variable.NewContext(ctx)
-		defer variable.ReleaseVariableContext(vc)
+		defer variable.ReleaseContext(vc)
 		for key, value := range p.config.Headers.SetResponse {
 			expanded := vc.Expand(value)
 			ctx.Response.Header.Set(key, expanded)
@@ -712,13 +717,14 @@ func isWebSocketRequest(ctx *fasthttp.RequestCtx) bool {
 }
 
 // handleWebSocket 处理 WebSocket 升级请求（保留用于兼容性，实际逻辑在 ServeHTTP 中）
+//
 //nolint:unused // 保留用于未来 WebSocket 功能扩展
 func (p *Proxy) handleWebSocket(ctx *fasthttp.RequestCtx, target *loadbalance.Target, _ *fasthttp.HostClient) {
 	timeout := p.config.Timeout.Connect
 	if timeout == 0 {
 		timeout = 30 * time.Second
 	}
-	if err := ProxyWebSocket(ctx, target, timeout); err != nil {
+	if err := WebSocket(ctx, target, timeout); err != nil {
 		logging.Error().Msgf("WebSocket proxy error: %v", err)
 	}
 }

internal/proxy/proxy_dns.go

@@ -170,13 +170,13 @@ func (p *Proxy) getResolverTTL() time.Duration {
 }
 
 // GetResolverStats 返回 DNS 解析器的统计信息。
-func (p *Proxy) GetResolverStats() resolver.ResolverStats {
+func (p *Proxy) GetResolverStats() resolver.Stats {
 	p.mu.RLock()
 	r := p.resolver
 	p.mu.RUnlock()
 
 	if r == nil {
-		return resolver.ResolverStats{}
+		return resolver.Stats{}
 	}
 	return r.Stats()
 }

internal/proxy/proxy_test.go

@@ -1287,8 +1287,8 @@ func TestFinalizeUpstreamVars(t *testing.T) {
 	ctx.Request.Header.SetMethod("GET")
 	ctx.Request.Header.SetRequestURI("/test")
 
-	vc := variable.NewVariableContext(ctx)
+	vc := variable.NewContext(ctx)
-	defer variable.ReleaseVariableContext(vc)
+	defer variable.ReleaseContext(vc)
 
 	timing := NewUpstreamTiming()
 	timing.MarkConnectStart()

internal/proxy/websocket.go

@@ -11,7 +11,7 @@
 //
 // 使用示例：
 //
-//	err := proxy.ProxyWebSocket(ctx, target, 30*time.Second)
+//	err := proxy.WebSocket(ctx, target, 30*time.Second)
 //	if err != nil {
 //	    log.Printf("WebSocket proxy error: %v", err)
 //	}
@@ -337,7 +337,7 @@ func readWebSocketUpgradeResponse(conn net.Conn, timeout time.Duration) (*http.R
 	return resp, nil
 }
 
-// ProxyWebSocket 处理 WebSocket 代理请求。
+// WebSocket 处理 WebSocket 代理请求。
 //
 // 完整流程：
 //  1. 劫持客户端连接
@@ -353,7 +353,7 @@ func readWebSocketUpgradeResponse(conn net.Conn, timeout time.Duration) (*http.R
 //
 // 返回值：
 //   - error: 代理过程中的错误
-func ProxyWebSocket(ctx *fasthttp.RequestCtx, target *loadbalance.Target, timeout time.Duration) error {
+func WebSocket(ctx *fasthttp.RequestCtx, target *loadbalance.Target, timeout time.Duration) error {
 	// 使用 Hijack 获取客户端 TCP 连接
 	var clientConn net.Conn
 

internal/proxy/websocket_test.go

@@ -122,7 +122,7 @@ func TestIsConnectionClosedError(t *testing.T) {
 }
 
 // TestExtractHost 测试从 URL 提取主机
-func TestExtractHost(t *testing.T) {
+func TestExtractHost(_ *testing.T) {
 	// extractHost 函数可能不存在，检查一下
 	// 如果存在则测试
 }