feat: Add ExtractTokenFromRequest method in Gate struct

gate.go

@@ -181,12 +181,7 @@ func (gate *Gate) ProtectFuncWithPermissions(handlerFunc http.HandlerFunc, permi
 			}
 		}
 		if gate.authorizationService != nil {
-			var token string
-			if gate.customTokenExtractorFunc != nil {
-				token = gate.customTokenExtractorFunc(request)
-			} else {
-				token = extractTokenFromRequest(request)
-			}
+			token := gate.ExtractTokenFromRequest(request)
 			if !gate.authorizationService.IsAuthorized(token, permissions) {
 				writer.WriteHeader(http.StatusUnauthorized)
 				_, _ = writer.Write(gate.unauthorizedResponseBody)
@@ -206,7 +201,17 @@ func (gate *Gate) ProtectFuncWithPermission(handlerFunc http.HandlerFunc, permis
 	return gate.ProtectFuncWithPermissions(handlerFunc, []string{permission})
 }
 
-// extractTokenFromRequest extracts the bearer token from the AuthorizationHeader
-func extractTokenFromRequest(request *http.Request) string {
+// ExtractTokenFromRequest extracts a token from a request.
+//
+// By default, it extracts the bearer token from the AuthorizationHeader, but if a customTokenExtractorFunc is defined,
+// it will use that instead.
+//
+// Note that this method is internally used by Protect, ProtectWithPermission, ProtectFunc and
+// ProtectFuncWithPermissions, but it is exposed in case you need to use it directly.
+func (gate *Gate) ExtractTokenFromRequest(request *http.Request) string {
+	if gate.customTokenExtractorFunc != nil {
+		// A custom token extractor function is defined, so we'll use it instead of the default token extraction logic
+		return gate.customTokenExtractorFunc(request)
+	}
 	return strings.TrimPrefix(request.Header.Get(AuthorizationHeader), "Bearer ")
 }

gate_bench_test.go

@@ -179,3 +179,30 @@ func BenchmarkGate_ProtectWithClientProviderConcurrently(b *testing.B) {
 	})
 	b.ReportAllocs()
 }
+
+func BenchmarkGate_ProtectWithValidTokenAndCustomTokenExtractorFuncConcurrently(b *testing.B) {
+	customTokenExtractorFunc := func(request *http.Request) string {
+		sessionCookie, err := request.Cookie("session")
+		if err != nil {
+			return ""
+		}
+		return sessionCookie.Value
+	}
+	gate := New().WithAuthorizationService(NewAuthorizationService().WithToken("good-token")).WithCustomTokenExtractor(customTokenExtractorFunc)
+	request, _ := http.NewRequest("GET", "/handle", http.NoBody)
+	request.AddCookie(&http.Cookie{Name: "session", Value: "good-token"})
+
+	router := http.NewServeMux()
+	router.Handle("/handle", gate.Protect(handler))
+
+	b.RunParallel(func(pb *testing.PB) {
+		for pb.Next() {
+			responseRecorder := httptest.NewRecorder()
+			router.ServeHTTP(responseRecorder, request)
+			if responseRecorder.Code != http.StatusOK {
+				b.Fatalf("%s %s should have returned %d, but returned %d instead", request.Method, request.URL, http.StatusOK, responseRecorder.Code)
+			}
+		}
+	})
+	b.ReportAllocs()
+}