Replace Flusher interface with http.ResponseController Flush() method

http/codegen/templates/server_handler_init.go.tpl

@@ -117,9 +117,7 @@ func {{ .HandlerInit }}(
 							errhandler(ctx, w, err)
 						}
 					} else {
-						if f, ok := w.(http.Flusher); ok {
-							f.Flush()
-						}
+						http.NewResponseController(w).Flush()
 						panic(http.ErrAbortHandler) // too late to write an error
 					}
 				}
@@ -140,9 +138,7 @@ func {{ .HandlerInit }}(
 				return
 			}
 			if _, err := io.Copy(w, buf); err != nil {
-				if f, ok := w.(http.Flusher); ok {
-					f.Flush()
-				}
+				http.NewResponseController(w).Flush()
 				panic(http.ErrAbortHandler) // too late to write an error
 			}
 		{{- else }}
@@ -255,9 +251,7 @@ func {{ .HandlerInit }}(
 						errhandler(ctx, w, err)
 					}
 				} else {
-					if f, ok := w.(http.Flusher); ok {
-						f.Flush()
-					}
+					http.NewResponseController(w).Flush()
 					panic(http.ErrAbortHandler) // too late to write an error
 				}
 			}
@@ -284,9 +278,7 @@ func {{ .HandlerInit }}(
 	{{- end }}
 	{{- if .Method.SkipResponseBodyEncodeDecode }}
 		if _, err := io.Copy(w, buf); err != nil {
-			if f, ok := w.(http.Flusher); ok {
-				f.Flush()
-			}
+			http.NewResponseController(w).Flush()
 			panic(http.ErrAbortHandler) // too late to write an error
 		}
 	{{- end }}

http/codegen/templates/server_sse.go.tpl

@@ -38,7 +38,7 @@ func (s *{{ .SSE.StructName }}) {{ .SSE.SendWithContextName }}(ctx context.Conte
 	{{- else }}
 	res := v
 	{{- end }}
-	
+
 	{{ if .SSE.IDField }}
 	if id := res.{{ .SSE.IDField }}; id != "" {
 		fmt.Fprintf(s.w, "id: %s\n", id)
@@ -66,10 +66,8 @@ func (s *{{ .SSE.StructName }}) {{ .SSE.SendWithContextName }}(ctx context.Conte
 	{{- end }}
 	fmt.Fprintf(s.w, "data: %s\n\n", data)
 
-	if f, ok := s.w.(http.Flusher); ok {
-		f.Flush()
-	}
-    return nil
+	http.NewResponseController(s.w).Flush()
+	return nil
 }
 
 {{ comment "Close is a no-op for SSE. We keep the method for compatibility with other stream types." }}

http/codegen/testdata/golden/handler_skip response body encode decode.go.golden

@@ -41,9 +41,7 @@ func NewMethodSkipResponseBodyEncodeDecodeHandler(
 						errhandler(ctx, w, err)
 					}
 				} else {
-					if f, ok := w.(http.Flusher); ok {
-						f.Flush()
-					}
+					http.NewResponseController(w).Flush()
 					panic(http.ErrAbortHandler) // too late to write an error
 				}
 			}
@@ -64,9 +62,7 @@ func NewMethodSkipResponseBodyEncodeDecodeHandler(
 			return
 		}
 		if _, err := io.Copy(w, buf); err != nil {
-			if f, ok := w.(http.Flusher); ok {
-				f.Flush()
-			}
+			http.NewResponseController(w).Flush()
 			panic(http.ErrAbortHandler) // too late to write an error
 		}
 	})

http/codegen/testdata/golden/sse-all-fields.golden

@@ -55,9 +55,7 @@ func (s *SSEAllFieldsMethodServerStream) SendWithContext(ctx context.Context, v
 	data = string(byts)
 	fmt.Fprintf(s.w, "data: %s\n\n", data)
 
-	if f, ok := s.w.(http.Flusher); ok {
-		f.Flush()
-	}
+	http.NewResponseController(s.w).Flush()
 	return nil
 }
 

http/codegen/testdata/golden/sse-bool.golden

@@ -41,9 +41,7 @@ func (s *SSEBoolMethodServerStream) SendWithContext(ctx context.Context, v bool)
 	data = string(byts)
 	fmt.Fprintf(s.w, "data: %s\n\n", data)
 
-	if f, ok := s.w.(http.Flusher); ok {
-		f.Flush()
-	}
+	http.NewResponseController(s.w).Flush()
 	return nil
 }
 

http/codegen/testdata/golden/sse-data-field.golden

@@ -41,9 +41,7 @@ func (s *SSEDataFieldMethodServerStream) SendWithContext(ctx context.Context, v
 	data = dataField
 	fmt.Fprintf(s.w, "data: %s\n\n", data)
 
-	if f, ok := s.w.(http.Flusher); ok {
-		f.Flush()
-	}
+	http.NewResponseController(s.w).Flush()
 	return nil
 }
 

http/codegen/testdata/golden/sse-data-id-field.golden

@@ -45,9 +45,7 @@ func (s *SSEDataIDFieldMethodServerStream) SendWithContext(ctx context.Context,
 	data = dataField
 	fmt.Fprintf(s.w, "data: %s\n\n", data)
 
-	if f, ok := s.w.(http.Flusher); ok {
-		f.Flush()
-	}
+	http.NewResponseController(s.w).Flush()
 	return nil
 }
 

http/codegen/testdata/golden/sse-int.golden

@@ -37,9 +37,7 @@ func (s *SSEIntMethodServerStream) SendWithContext(ctx context.Context, v int) e
 	data = fmt.Sprintf("%d", res)
 	fmt.Fprintf(s.w, "data: %s\n\n", data)
 
-	if f, ok := s.w.(http.Flusher); ok {
-		f.Flush()
-	}
+	http.NewResponseController(s.w).Flush()
 	return nil
 }
 

http/codegen/testdata/golden/sse-object.golden

@@ -43,9 +43,7 @@ func (s *SSEObjectMethodServerStream) SendWithContext(ctx context.Context, v *ss
 	data = string(byts)
 	fmt.Fprintf(s.w, "data: %s\n\n", data)
 
-	if f, ok := s.w.(http.Flusher); ok {
-		f.Flush()
-	}
+	http.NewResponseController(s.w).Flush()
 	return nil
 }
 

http/codegen/testdata/golden/sse-request-id.golden

@@ -38,9 +38,7 @@ func (s *SSERequestIDMethodServerStream) SendWithContext(ctx context.Context, v
 	data = res
 	fmt.Fprintf(s.w, "data: %s\n\n", data)
 
-	if f, ok := s.w.(http.Flusher); ok {
-		f.Flush()
-	}
+	http.NewResponseController(s.w).Flush()
 	return nil
 }
 

http/codegen/testdata/golden/sse-string.golden

@@ -38,9 +38,7 @@ func (s *SSEStringMethodServerStream) SendWithContext(ctx context.Context, v str
 	data = res
 	fmt.Fprintf(s.w, "data: %s\n\n", data)
 
-	if f, ok := s.w.(http.Flusher); ok {
-		f.Flush()
-	}
+	http.NewResponseController(s.w).Flush()
 	return nil
 }
 

http/codegen/testdata/handler_init_functions.go

@@ -295,9 +295,7 @@ func NewMethodSkipResponseBodyEncodeDecodeHandler(
 						errhandler(ctx, w, err)
 					}
 				} else {
-					if f, ok := w.(http.Flusher); ok {
-						f.Flush()
-					}
+					http.NewResponseController(w).Flush()
 					panic(http.ErrAbortHandler) // too late to write an error
 				}
 			}
@@ -318,9 +316,7 @@ func NewMethodSkipResponseBodyEncodeDecodeHandler(
 			return
 		}
 		if _, err := io.Copy(w, buf); err != nil {
-			if f, ok := w.(http.Flusher); ok {
-				f.Flush()
-			}
+			http.NewResponseController(w).Flush()
 			panic(http.ErrAbortHandler) // too late to write an error
 		}
 	})

http/middleware/capture.go

@@ -41,12 +41,9 @@ func (w *ResponseCapture) Write(b []byte) (int, error) {
 	return n, err
 }
 
-// Flush implements the http.Flusher interface if the underlying response
-// writer supports it.
+// Flush call http.ResponseController Flush() method
 func (w *ResponseCapture) Flush() {
-	if f, ok := w.ResponseWriter.(http.Flusher); ok {
-		f.Flush()
-	}
+	_ = http.NewResponseController(w.ResponseWriter).Flush()
 }
 
 // Push implements the http.Pusher interface if the underlying response

jsonrpc/codegen/templates/sse_server_stream.go.tpl

@@ -6,7 +6,7 @@ type {{ .SSE.StructName }} struct {
 	encoder func(context.Context, http.ResponseWriter) goahttp.Encoder
 	// w is the HTTP response writer
 	w http.ResponseWriter
-	// r is the HTTP request  
+	// r is the HTTP request
 	r *http.Request
 	// requestID is the JSON-RPC request ID for sending final response
 	requestID any
@@ -39,9 +39,7 @@ func (s *{{ lowerInitial .SSE.StructName }}EventWriter) Write(data []byte) (int,
 func (s *{{ lowerInitial .SSE.StructName }}EventWriter) finish() {
 	if s.started {
 		s.w.Write([]byte("\n\n"))
-		if f, ok := s.w.(http.Flusher); ok {
-			f.Flush()
-		}
+		http.NewResponseController(s.w).Flush()
 	}
 }
 
@@ -55,27 +53,27 @@ func (s *{{ .SSE.StructName }}) Send(ctx context.Context, event {{ .ServicePkgNa
 		return fmt.Errorf("stream closed")
 	}
 	s.mu.Unlock()
-	
+
 	{{ comment "Type assert to the specific result type" }}
 	result, ok := event.({{ .SSE.EventTypeRef }})
 	if !ok {
 		return fmt.Errorf("unexpected event type: %T", event)
 	}
-	
+
 	{{- if and .Result (index .Result.Responses 0).ServerBody (index (index .Result.Responses 0).ServerBody 0).Init }}
 	{{ comment "Convert to response body type for proper JSON encoding" }}
 	body := {{ (index (index .Result.Responses 0).ServerBody 0).Init.Name }}(result)
 	{{- else }}
 	body := result
 	{{- end }}
-	
+
 	{{ comment "Send as notification (no ID)" }}
 	message := map[string]any{
 		"jsonrpc": "2.0",
 		"method":  {{ printf "%q" .Method.Name }},
 		"params":  body,
 	}
-	
+
 	return s.sendSSEEvent("notification", message)
 }
 
@@ -91,13 +89,13 @@ func (s *{{ .SSE.StructName }}) SendAndClose(ctx context.Context, event {{ .Serv
 	}
 	s.closed = true
 	s.mu.Unlock()
-	
+
 	{{ comment "Type assert to the specific result type" }}
 	result, ok := event.({{ .SSE.EventTypeRef }})
 	if !ok {
 		return fmt.Errorf("unexpected event type: %T", event)
 	}
-	
+
 	{{ comment "Determine the ID to use for the response" }}
 	var id any = s.requestID
 	{{- if .Result.IDAttribute }}
@@ -117,21 +115,21 @@ func (s *{{ .SSE.StructName }}) SendAndClose(ctx context.Context, event {{ .Serv
 	}
 		{{- end }}
 	{{- end }}
-	
+
 	{{- if and .Result (index .Result.Responses 0).ServerBody (index (index .Result.Responses 0).ServerBody 0).Init }}
 	{{ comment "Convert to response body type for proper JSON encoding" }}
 	body := {{ (index (index .Result.Responses 0).ServerBody 0).Init.Name }}(result)
 	{{- else }}
 	body := result
 	{{- end }}
-	
+
 	{{ comment "Send as response with ID" }}
 	message := map[string]any{
 		"jsonrpc": "2.0",
 		"id":      id,
 		"result":  body,
 	}
-	
+
 	return s.sendSSEEvent("response", message)
 }
 
@@ -189,12 +187,12 @@ func (s *{{ .SSE.StructName }}) sendSSEEvent(eventType string, v any) error {
 
 	// Create SSE event writer that wraps the response writer
 	ew := &{{ lowerInitial .SSE.StructName }}EventWriter{w: s.w, eventType: eventType}
-	
+
 	// Create encoder with the event writer and encode the value
 	err := s.encoder(context.Background(), ew).Encode(v)
-	
+
 	// Finish the SSE event (adds newlines and flushes)
 	ew.finish()
-	
+
 	return err
 }