fix: 修正 conversion 代理路径和错误边界

backend/internal/provider/client_test.go

@@ -110,11 +110,13 @@ func TestClient_SendStream_CreatesChannel(t *testing.T) {
 		Body:    []byte(`{}`),
 	}
 
-	eventChan, err := client.SendStream(context.Background(), spec)
+	streamResp, err := client.SendStream(context.Background(), spec)
 	require.NoError(t, err)
-	require.NotNil(t, eventChan)
+	require.NotNil(t, streamResp)
+	require.Equal(t, http.StatusOK, streamResp.StatusCode)
+	require.NotNil(t, streamResp.Events)
 
-	for range eventChan {
+	for range streamResp.Events {
 	}
 }
 
@@ -132,8 +134,10 @@ func TestClient_SendStream_ErrorResponse(t *testing.T) {
 		Body:    []byte(`{}`),
 	}
 
-	_, err := client.SendStream(context.Background(), spec)
-	assert.Error(t, err)
+	streamResp, err := client.SendStream(context.Background(), spec)
+	require.NoError(t, err)
+	require.NotNil(t, streamResp)
+	assert.Equal(t, http.StatusInternalServerError, streamResp.StatusCode)
 }
 
 func TestClient_SendStream_SSEEvents(t *testing.T) {
@@ -164,12 +168,13 @@ func TestClient_SendStream_SSEEvents(t *testing.T) {
 		Body:    []byte(`{"model":"gpt-4","messages":[],"stream":true}`),
 	}
 
-	eventChan, err := client.SendStream(context.Background(), spec)
+	streamResp, err := client.SendStream(context.Background(), spec)
 	require.NoError(t, err)
+	require.NotNil(t, streamResp)
 
 	var dataEvents [][]byte
 	var doneEvents int
-	for event := range eventChan {
+	for event := range streamResp.Events {
 		switch {
 		case event.Done:
 			doneEvents++
@@ -180,9 +185,56 @@ func TestClient_SendStream_SSEEvents(t *testing.T) {
 		}
 	}
 
-	assert.Equal(t, 2, len(dataEvents), "expected exactly 2 data events from SSE stream")
+	assert.Equal(t, 3, len(dataEvents), "expected 2 data frames plus DONE frame from SSE stream")
 	assert.Contains(t, string(dataEvents[0]), "Hello")
 	assert.Contains(t, string(dataEvents[1]), "World")
+	assert.Contains(t, string(dataEvents[2]), "[DONE]")
+	assert.Equal(t, 1, doneEvents)
+	assert.Contains(t, string(dataEvents[0]), "\n\n")
+}
+
+func TestClient_SendStream_DONEOnlyWhenDataPayloadEqualsDone(t *testing.T) {
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", "text/event-stream")
+		w.WriteHeader(http.StatusOK)
+		flusher, ok := w.(http.Flusher)
+		require.True(t, ok)
+		_, err := w.Write([]byte("data: {\"text\":\"data: [DONE] is plain text\"}\n\n"))
+		require.NoError(t, err)
+		flusher.Flush()
+		_, err = w.Write([]byte("data: [DONE]\n\n"))
+		require.NoError(t, err)
+		flusher.Flush()
+	}))
+	defer server.Close()
+
+	client := NewClient(zap.NewNop())
+	spec := conversion.HTTPRequestSpec{
+		URL:    server.URL + "/v1/chat/completions",
+		Method: "POST",
+		Body:   []byte(`{}`),
+	}
+
+	streamResp, err := client.SendStream(context.Background(), spec)
+	require.NoError(t, err)
+	require.NotNil(t, streamResp)
+
+	var dataEvents [][]byte
+	var doneEvents int
+	for event := range streamResp.Events {
+		switch {
+		case event.Done:
+			doneEvents++
+		case event.Error != nil:
+			t.Fatalf("unexpected error: %v", event.Error)
+		default:
+			dataEvents = append(dataEvents, event.Data)
+		}
+	}
+
+	require.Len(t, dataEvents, 2)
+	assert.Contains(t, string(dataEvents[0]), "plain text")
+	assert.Contains(t, string(dataEvents[1]), "[DONE]")
 	assert.Equal(t, 1, doneEvents)
 }
 
@@ -203,13 +255,13 @@ func TestClient_SendStream_ContextCancellation(t *testing.T) {
 		Body:    []byte(`{}`),
 	}
 
-	eventChan, err := client.SendStream(ctx, spec)
+	streamResp, err := client.SendStream(ctx, spec)
 	require.NoError(t, err)
 
 	cancel()
 
 	var gotError bool
-	for event := range eventChan {
+	for event := range streamResp.Events {
 		if event.Error != nil {
 			gotError = true
 		}
@@ -264,12 +316,12 @@ func TestClient_SendStream_SlowSSE(t *testing.T) {
 		Body:    []byte(`{}`),
 	}
 
-	eventChan, err := client.SendStream(context.Background(), spec)
+	streamResp, err := client.SendStream(context.Background(), spec)
 	require.NoError(t, err)
 
 	var dataCount int
 	var doneCount int
-	for event := range eventChan {
+	for event := range streamResp.Events {
 		switch {
 		case event.Done:
 			doneCount++
@@ -279,7 +331,7 @@ func TestClient_SendStream_SlowSSE(t *testing.T) {
 			dataCount++
 		}
 	}
-	assert.Equal(t, 1, dataCount, "expected exactly 1 data event from slow SSE")
+	assert.Equal(t, 2, dataCount, "expected 1 data frame plus DONE frame from slow SSE")
 	assert.Equal(t, 1, doneCount, "expected exactly 1 done event from slow SSE")
 }
 
@@ -308,19 +360,19 @@ func TestClient_SendStream_SplitSSEEvents(t *testing.T) {
 		Body:    []byte(`{}`),
 	}
 
-	eventChan, err := client.SendStream(context.Background(), spec)
+	streamResp, err := client.SendStream(context.Background(), spec)
 	require.NoError(t, err)
 
 	var dataEvents int
 	var doneEvents int
-	for event := range eventChan {
+	for event := range streamResp.Events {
 		if event.Done {
 			doneEvents++
 		} else {
 			dataEvents++
 		}
 	}
-	assert.Equal(t, 2, dataEvents, "expected exactly 2 data events from split SSE")
+	assert.Equal(t, 3, dataEvents, "expected 2 data frames plus DONE frame from split SSE")
 	assert.Equal(t, 1, doneEvents)
 }
 
@@ -397,11 +449,11 @@ func TestClient_SendStream_MidStreamNetworkError(t *testing.T) {
 		Body:    []byte(`{}`),
 	}
 
-	eventChan, err := client.SendStream(context.Background(), spec)
+	streamResp, err := client.SendStream(context.Background(), spec)
 	require.NoError(t, err)
 
 	var gotData bool
-	for event := range eventChan {
+	for event := range streamResp.Events {
 		if event.Error != nil {
 		} else if !event.Done {
 			gotData = true