refactor: applies linting.

middlewares/accesslog/logger.go

@@ -272,7 +272,7 @@ func (h *Handler) logTheRoundTrip(logDataTable *LogData, crr *captureRequestRead
 		core[DownstreamContentSize] = crw.Size()
 		if original, ok := core[OriginContentSize]; ok {
 			o64 := original.(int64)
-			if o64 != crw.Size() && 0 != crw.Size() {
+			if crw.Size() != o64 && crw.Size() != 0 {
 				core[GzipRatio] = float64(o64) / float64(crw.Size())
 			}
 		}

middlewares/auth/forward.go

@@ -167,19 +167,23 @@ func writeHeader(req *http.Request, forwardReq *http.Request, trustForwardHeader
 		forwardReq.Header.Set(forward.XForwardedFor, clientIP)
 	}
 
-	if xMethod := req.Header.Get(xForwardedMethod); xMethod != "" && trustForwardHeader {
+	xMethod := req.Header.Get(xForwardedMethod)
+	switch {
+	case xMethod != "" && trustForwardHeader:
 		forwardReq.Header.Set(xForwardedMethod, xMethod)
-	} else if req.Method != "" {
+	case req.Method != "":
 		forwardReq.Header.Set(xForwardedMethod, req.Method)
-	} else {
+	default:
 		forwardReq.Header.Del(xForwardedMethod)
 	}
 
-	if xfp := req.Header.Get(forward.XForwardedProto); xfp != "" && trustForwardHeader {
+	xfp := req.Header.Get(forward.XForwardedProto)
+	switch {
+	case xfp != "" && trustForwardHeader:
 		forwardReq.Header.Set(forward.XForwardedProto, xfp)
-	} else if req.TLS != nil {
+	case req.TLS != nil:
 		forwardReq.Header.Set(forward.XForwardedProto, "https")
-	} else {
+	default:
 		forwardReq.Header.Set(forward.XForwardedProto, "http")
 	}
 
@@ -187,19 +191,23 @@ func writeHeader(req *http.Request, forwardReq *http.Request, trustForwardHeader
 		forwardReq.Header.Set(forward.XForwardedPort, xfp)
 	}
 
-	if xfh := req.Header.Get(forward.XForwardedHost); xfh != "" && trustForwardHeader {
+	xfh := req.Header.Get(forward.XForwardedHost)
+	switch {
+	case xfh != "" && trustForwardHeader:
 		forwardReq.Header.Set(forward.XForwardedHost, xfh)
-	} else if req.Host != "" {
+	case req.Host != "":
 		forwardReq.Header.Set(forward.XForwardedHost, req.Host)
-	} else {
+	default:
 		forwardReq.Header.Del(forward.XForwardedHost)
 	}
 
-	if xfURI := req.Header.Get(xForwardedURI); xfURI != "" && trustForwardHeader {
+	xfURI := req.Header.Get(xForwardedURI)
+	switch {
+	case xfURI != "" && trustForwardHeader:
 		forwardReq.Header.Set(xForwardedURI, xfURI)
-	} else if req.URL.RequestURI() != "" {
+	case req.URL.RequestURI() != "":
 		forwardReq.Header.Set(xForwardedURI, req.URL.RequestURI())
-	} else {
+	default:
 		forwardReq.Header.Del(xForwardedURI)
 	}
 }

middlewares/headers/headers_test.go

@@ -106,7 +106,7 @@ func TestSecureHeader(t *testing.T) {
 
 func TestSSLForceHost(t *testing.T) {
 	next := http.HandlerFunc(func(rw http.ResponseWriter, req *http.Request) {
-		rw.Write([]byte("OK"))
+		_, _ = rw.Write([]byte("OK"))
 	})
 
 	testCases := []struct {

middlewares/passtlsclientcert/pass_tls_client_cert.go

@@ -271,7 +271,8 @@ func getSANs(cert *x509.Certificate) []string {
 		return sans
 	}
 
-	sans = append(cert.DNSNames, cert.EmailAddresses...)
+	sans = append(sans, cert.DNSNames...)
+	sans = append(sans, cert.EmailAddresses...)
 
 	var ips []string
 	for _, ip := range cert.IPAddresses {

middlewares/retry/retry_test.go

@@ -256,7 +256,7 @@ func TestRetryWebsocket(t *testing.T) {
 
 	forwarder, err := forward.New()
 	if err != nil {
-		t.Fatalf("Error creating forwarder: %s", err)
+		t.Fatalf("Error creating forwarder: %v", err)
 	}
 
 	backendServer := httptest.NewServer(http.HandlerFunc(func(rw http.ResponseWriter, req *http.Request) {
@@ -274,7 +274,7 @@ func TestRetryWebsocket(t *testing.T) {
 
 			loadBalancer, err := roundrobin.New(forwarder)
 			if err != nil {
-				t.Fatalf("Error creating load balancer: %s", err)
+				t.Fatalf("Error creating load balancer: %v", err)
 			}
 
 			basePort := 33444
@@ -287,7 +287,10 @@ func TestRetryWebsocket(t *testing.T) {
 			}
 
 			// add the functioning server to the end of the load balancer list
-			loadBalancer.UpsertServer(testhelpers.MustParseURL(backendServer.URL))
+			err = loadBalancer.UpsertServer(testhelpers.MustParseURL(backendServer.URL))
+			if err != nil {
+				t.Fatalf("Fail to upsert server: %v", err)
+			}
 
 			retryListener := &countingRetryListener{}
 			retryH, err := New(context.Background(), loadBalancer, config.Retry{Attempts: test.maxRequestAttempts}, retryListener, "traefikTest")