Add func RunHttp3 in gin.go, which support both TLS/TCP and QUIC in…

… parallel.

gin.go

@@ -582,6 +582,23 @@ func (engine *Engine) RunQUIC(addr, certFile, keyFile string) (err error) {
 	return
 }
 
+// RunHttp3 attaches the router to a http.Server and starts listening
+// and serving both TLS/TCP and QUIC requests in parallel.
+// It is a shortcut for http3.ListenAndServe(addr, certFile, keyFile, router)
+// Note: this method will block the calling goroutine indefinitely unless an error happens.
+func (engine *Engine) RunHttp3(addr, certFile, keyFile string) (err error) {
+	debugPrint("Listening and serving both HTTPS and QUIC on %s\n", addr)
+	defer func() { debugPrintError(err) }()
+
+	if engine.isUnsafeTrustedProxies() {
+		debugPrint("[WARNING] You trusted all proxies, this is NOT safe. We recommend you to set a value.\n" +
+			"Please check https://pkg.go.dev/github.com/gin-gonic/gin#readme-don-t-trust-all-proxies for details.")
+	}
+
+	err = http3.ListenAndServe(addr, certFile, keyFile, engine.Handler())
+	return
+}
+
 // RunListener attaches the router to a http.Server and starts listening and serving HTTP requests
 // through the specified net.Listener
 func (engine *Engine) RunListener(listener net.Listener) (err error) {

gin_integration_test.go

@@ -290,6 +290,22 @@ func TestRunQUIC(t *testing.T) {
 	testRequest(t, "https://localhost:8443/example")
 }
 
+func TestRunHttp3(t *testing.T) {
+	router := New()
+	go func() {
+		router.GET("/example", func(c *Context) { c.String(http.StatusOK, "it worked") })
+
+		assert.NoError(t, router.RunHttp3(":2396", "./testdata/certificate/cert.pem", "./testdata/certificate/key.pem"))
+	}()
+
+	// have to wait for the goroutine to start and run the server
+	// otherwise the main thread will complete
+	time.Sleep(5 * time.Millisecond)
+
+	assert.Error(t, router.RunHttp3(":2396", "./testdata/certificate/cert.pem", "./testdata/certificate/key.pem"))
+	testRequest(t, "https://localhost:2396/example")
+}
+
 func TestFileDescriptor(t *testing.T) {
 	router := New()