chore: refactor httpx.TimeoutHandler (#3400)

rest/handler/timeouthandler.go

@@ -127,18 +127,29 @@ type timeoutWriter struct {
 
 var _ http.Pusher = (*timeoutWriter)(nil)
 
+// Flush implements the Flusher interface.
 func (tw *timeoutWriter) Flush() {
-	dst := tw.w.Header()
-	for k, vv := range tw.h {
-		dst[k] = vv
+	flusher, ok := tw.w.(http.Flusher)
+	if !ok {
+		return
 	}
-	if flusher, ok := tw.w.(http.Flusher); ok {
+
+	header := tw.w.Header()
+	for k, v := range tw.h {
+		header[k] = v
+	}
+
 	tw.w.Write(tw.wbuf.Bytes())
 	tw.wbuf.Reset()
 	flusher.Flush()
-	}
 }
 
+// Header returns the underline temporary http.Header.
+func (tw *timeoutWriter) Header() http.Header {
+	return tw.h
+}
+
+// Hijack implements the Hijacker interface.
 func (tw *timeoutWriter) Hijack() (net.Conn, *bufio.ReadWriter, error) {
 	if hijacked, ok := tw.w.(http.Hijacker); ok {
 		return hijacked.Hijack()
@@ -147,14 +158,12 @@ func (tw *timeoutWriter) Hijack() (net.Conn, *bufio.ReadWriter, error) {
 	return nil, nil, errors.New("server doesn't support hijacking")
 }
 
-// Header returns the underline temporary http.Header.
-func (tw *timeoutWriter) Header() http.Header { return tw.h }
-
 // Push implements the Pusher interface.
 func (tw *timeoutWriter) Push(target string, opts *http.PushOptions) error {
 	if pusher, ok := tw.w.(http.Pusher); ok {
 		return pusher.Push(target, opts)
 	}
+
 	return http.ErrNotSupported
 }
 
@@ -171,6 +180,7 @@ func (tw *timeoutWriter) Write(p []byte) (int, error) {
 	if !tw.wroteHeader {
 		tw.writeHeaderLocked(http.StatusOK)
 	}
+
 	return tw.wbuf.Write(p)
 }
 

rest/handler/timeouthandler_test.go

@@ -17,16 +17,18 @@ import (
 )
 
 func TestTimeoutWriteFlushOutput(t *testing.T) {
+	t.Run("flusher", func(t *testing.T) {
 		timeoutHandler := TimeoutHandler(1000 * time.Millisecond)
 		handler := timeoutHandler(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-		w.Header().Set("Content-Type", "text/event-stream;charset=utf-8")
+			w.Header().Set("Content-Type", "text/event-stream; charset=utf-8")
 			flusher, ok := w.(http.Flusher)
 			if !ok {
 				http.Error(w, "Flushing not supported", http.StatusInternalServerError)
 				return
 			}
+
 			for i := 1; i <= 5; i++ {
-			fmt.Fprint(w, strconv.Itoa(i)+"只猫猫\n\n")
+				fmt.Fprint(w, strconv.Itoa(i)+" cats\n\n")
 				flusher.Flush()
 				time.Sleep(time.Millisecond)
 			}
@@ -35,17 +37,43 @@ func TestTimeoutWriteFlushOutput(t *testing.T) {
 		resp := httptest.NewRecorder()
 		handler.ServeHTTP(resp, req)
 		scanner := bufio.NewScanner(resp.Body)
-	mao := 0
+		var cats int
 		for scanner.Scan() {
 			line := scanner.Text()
-		if strings.Contains(line, "猫猫") {
-			mao++
+			if strings.Contains(line, "cats") {
+				cats++
 			}
 		}
 		if err := scanner.Err(); err != nil {
-		mao = 0
+			cats = 0
 		}
-	assert.Equal(t, "5只猫猫", strconv.Itoa(mao)+"只猫猫")
+		assert.Equal(t, 5, cats)
+	})
+
+	t.Run("writer", func(t *testing.T) {
+		recorder := httptest.NewRecorder()
+		timeoutHandler := TimeoutHandler(1000 * time.Millisecond)
+		handler := timeoutHandler(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			w.Header().Set("Content-Type", "text/event-stream; charset=utf-8")
+			flusher, ok := w.(http.Flusher)
+			if !ok {
+				http.Error(w, "Flushing not supported", http.StatusInternalServerError)
+				return
+			}
+
+			for i := 1; i <= 5; i++ {
+				fmt.Fprint(w, strconv.Itoa(i)+" cats\n\n")
+				flusher.Flush()
+				time.Sleep(time.Millisecond)
+				assert.Empty(t, recorder.Body.String())
+			}
+		}))
+		req := httptest.NewRequest(http.MethodGet, "http://localhost", http.NoBody)
+		resp := mockedResponseWriter{recorder}
+		handler.ServeHTTP(resp, req)
+		assert.Equal(t, "1 cats\n\n2 cats\n\n3 cats\n\n4 cats\n\n5 cats\n\n",
+			recorder.Body.String())
+	})
 }
 
 func TestTimeout(t *testing.T) {
@@ -274,3 +302,19 @@ func (m mockedPusher) WriteHeader(_ int) {
 func (m mockedPusher) Push(_ string, _ *http.PushOptions) error {
 	panic("implement me")
 }
+
+type mockedResponseWriter struct {
+	http.ResponseWriter
+}
+
+func (m mockedResponseWriter) Header() http.Header {
+	return m.ResponseWriter.Header()
+}
+
+func (m mockedResponseWriter) Write(bytes []byte) (int, error) {
+	return m.ResponseWriter.Write(bytes)
+}
+
+func (m mockedResponseWriter) WriteHeader(statusCode int) {
+	m.ResponseWriter.WriteHeader(statusCode)
+}