refactor(handlers): streamline error and data channel handling in streaming logic

Improved consistency across OpenAI, Claude, and Gemini handlers by replacing initial `select` statement with a `for` loop for better readability and error-handling robustness.

sdk/api/handlers/claude/code_handlers.go

@@ -212,11 +212,17 @@ func (h *ClaudeCodeAPIHandler) handleStreamingResponse(c *gin.Context, rawJSON [
 	}
 
 	// Peek at the first chunk to determine success or failure before setting headers
+	for {
 		select {
 		case <-c.Request.Context().Done():
 			cliCancel(c.Request.Context().Err())
 			return
-	case errMsg := <-errChan:
+		case errMsg, ok := <-errChan:
+			if !ok {
+				// Err channel closed cleanly; wait for data channel.
+				errChan = nil
+				continue
+			}
 			// Upstream failed immediately. Return proper error status and JSON.
 			h.WriteErrorResponse(c, errMsg)
 			if errMsg != nil {
@@ -245,6 +251,8 @@ func (h *ClaudeCodeAPIHandler) handleStreamingResponse(c *gin.Context, rawJSON [
 
 			// Continue streaming the rest
 			h.forwardClaudeStream(c, flusher, func(err error) { cliCancel(err) }, dataChan, errChan)
+			return
+		}
 	}
 }
 

sdk/api/handlers/gemini/gemini_handlers.go

@@ -249,11 +249,17 @@ func (h *GeminiAPIHandler) handleStreamGenerateContent(c *gin.Context, modelName
 	}
 
 	// Peek at the first chunk
+	for {
 		select {
 		case <-c.Request.Context().Done():
 			cliCancel(c.Request.Context().Err())
 			return
-	case errMsg := <-errChan:
+		case errMsg, ok := <-errChan:
+			if !ok {
+				// Err channel closed cleanly; wait for data channel.
+				errChan = nil
+				continue
+			}
 			// Upstream failed immediately. Return proper error status and JSON.
 			h.WriteErrorResponse(c, errMsg)
 			if errMsg != nil {
@@ -290,6 +296,8 @@ func (h *GeminiAPIHandler) handleStreamGenerateContent(c *gin.Context, modelName
 
 			// Continue
 			h.forwardGeminiStream(c, flusher, alt, func(err error) { cliCancel(err) }, dataChan, errChan)
+			return
+		}
 	}
 }
 

sdk/api/handlers/openai/openai_handlers.go

@@ -467,11 +467,17 @@ func (h *OpenAIAPIHandler) handleStreamingResponse(c *gin.Context, rawJSON []byt
 	}
 
 	// Peek at the first chunk to determine success or failure before setting headers
+	for {
 		select {
 		case <-c.Request.Context().Done():
 			cliCancel(c.Request.Context().Err())
 			return
-	case errMsg := <-errChan:
+		case errMsg, ok := <-errChan:
+			if !ok {
+				// Err channel closed cleanly; wait for data channel.
+				errChan = nil
+				continue
+			}
 			// Upstream failed immediately. Return proper error status and JSON.
 			h.WriteErrorResponse(c, errMsg)
 			if errMsg != nil {
@@ -498,6 +504,8 @@ func (h *OpenAIAPIHandler) handleStreamingResponse(c *gin.Context, rawJSON []byt
 
 			// Continue streaming the rest
 			h.handleStreamResult(c, flusher, func(err error) { cliCancel(err) }, dataChan, errChan)
+			return
+		}
 	}
 }
 
@@ -562,11 +570,17 @@ func (h *OpenAIAPIHandler) handleCompletionsStreamingResponse(c *gin.Context, ra
 	}
 
 	// Peek at the first chunk
+	for {
 		select {
 		case <-c.Request.Context().Done():
 			cliCancel(c.Request.Context().Err())
 			return
-	case errMsg := <-errChan:
+		case errMsg, ok := <-errChan:
+			if !ok {
+				// Err channel closed cleanly; wait for data channel.
+				errChan = nil
+				continue
+			}
 			h.WriteErrorResponse(c, errMsg)
 			if errMsg != nil {
 				cliCancel(errMsg.Error)
@@ -625,6 +639,8 @@ func (h *OpenAIAPIHandler) handleCompletionsStreamingResponse(c *gin.Context, ra
 				stop()
 				cliCancel(err)
 			}, convertedChan, errChan)
+			return
+		}
 	}
 }
 func (h *OpenAIAPIHandler) handleStreamResult(c *gin.Context, flusher http.Flusher, cancel func(error), data <-chan []byte, errs <-chan *interfaces.ErrorMessage) {

sdk/api/handlers/openai/openai_responses_handlers.go

@@ -152,11 +152,17 @@ func (h *OpenAIResponsesAPIHandler) handleStreamingResponse(c *gin.Context, rawJ
 	}
 
 	// Peek at the first chunk
+	for {
 		select {
 		case <-c.Request.Context().Done():
 			cliCancel(c.Request.Context().Err())
 			return
-	case errMsg := <-errChan:
+		case errMsg, ok := <-errChan:
+			if !ok {
+				// Err channel closed cleanly; wait for data channel.
+				errChan = nil
+				continue
+			}
 			// Upstream failed immediately. Return proper error status and JSON.
 			h.WriteErrorResponse(c, errMsg)
 			if errMsg != nil {
@@ -188,6 +194,8 @@ func (h *OpenAIResponsesAPIHandler) handleStreamingResponse(c *gin.Context, rawJ
 
 			// Continue
 			h.forwardResponsesStream(c, flusher, func(err error) { cliCancel(err) }, dataChan, errChan)
+			return
+		}
 	}
 }