feat: support native streaming responses

transport/native/server_test.go

@@ -225,6 +225,60 @@ func TestServerPipelinedRequestsAndLargeBody(t *testing.T) {
 	}
 }
 
+func TestServerFlushesChunkedResponses(t *testing.T) {
+	flushed := make(chan struct{})
+	release := make(chan struct{})
+	application := omni.NewWithRouter(netrouter.New())
+	application.GET("/stream", func(ctx *omni.Context) error {
+		flusher, ok := ctx.Raw().(http.Flusher)
+		if !ok {
+			return fmt.Errorf("native response writer does not implement http.Flusher")
+		}
+		ctx.Raw().Header().Set("Content-Type", "text/plain")
+		_, _ = io.WriteString(ctx.Raw(), "one\n")
+		flusher.Flush()
+		close(flushed)
+		<-release
+		_, _ = io.WriteString(ctx.Raw(), "two\n")
+		return nil
+	})
+	server, listener, done := startServer(t, application)
+	defer stopServer(t, server, listener, done)
+
+	conn, err := net.Dial("tcp", listener.Addr().String())
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer conn.Close()
+	reader := bufio.NewReader(conn)
+	_, _ = io.WriteString(conn, "GET /stream HTTP/1.1\r\nHost: test\r\nConnection: close\r\n\r\n")
+	response, err := http.ReadResponse(reader, &http.Request{Method: http.MethodGet})
+	if err != nil {
+		t.Fatal(err)
+	}
+	if response.StatusCode != http.StatusOK || response.TransferEncoding == nil || response.TransferEncoding[0] != "chunked" {
+		response.Body.Close()
+		t.Fatalf("expected chunked response, status=%d transfer=%v", response.StatusCode, response.TransferEncoding)
+	}
+	select {
+	case <-flushed:
+	case <-time.After(time.Second):
+		response.Body.Close()
+		t.Fatal("handler did not flush response")
+	}
+	first := make([]byte, len("one\n"))
+	if _, err := io.ReadFull(response.Body, first); err != nil || string(first) != "one\n" {
+		response.Body.Close()
+		t.Fatalf("unexpected first stream chunk: %q error=%v", first, err)
+	}
+	close(release)
+	rest, err := io.ReadAll(response.Body)
+	response.Body.Close()
+	if err != nil || string(rest) != "two\n" {
+		t.Fatalf("unexpected remaining stream body: %q error=%v", rest, err)
+	}
+}
+
 func TestServerProtocolBoundaries(t *testing.T) {
 	application := omni.NewWithRouter(netrouter.New())
 	application.GET("/health", func(ctx *omni.Context) error { return ctx.OK("ok") })