fix(chat): prevent duplicate renderer requests and thinking messages (#870)

Co-authored-by: Cursor Agent <cursoragent@cursor.com>
Co-authored-by: Haze <hazeone@users.noreply.github.com>

src/pages/Chat/ChatInput.tsx

@@ -491,6 +491,7 @@ export function ChatInput({ onSend, onStop, disabled = false, sending = false, i
                 onPaste={handlePaste}
                 placeholder={disabled ? t('composer.gatewayDisconnectedPlaceholder') : ''}
                 disabled={disabled}
+                data-testid="chat-composer-input"
                 className="min-h-[40px] max-h-[200px] resize-none border-0 focus-visible:ring-0 focus-visible:ring-offset-0 shadow-none bg-transparent py-2.5 px-2 text-[15px] placeholder:text-muted-foreground/60 leading-relaxed"
                 rows={1}
               />
@@ -501,6 +502,7 @@ export function ChatInput({ onSend, onStop, disabled = false, sending = false, i
               onClick={sending ? handleStop : handleSend}
               disabled={sending ? !canStop : !canSend}
               size="icon"
+              data-testid="chat-composer-send"
               className={`shrink-0 h-10 w-10 rounded-full transition-colors ${
                 (sending || canSend)
                   ? 'bg-black/5 dark:bg-white/10 text-foreground hover:bg-black/10 dark:hover:bg-white/20'

src/pages/Chat/message-utils.ts

@@ -25,6 +25,44 @@ function cleanUserText(text: string): string {
     .trim();
 }
 
+function normalizeProgressiveText(text: string | undefined): string {
+  return typeof text === 'string' ? text.replace(/\r\n/g, '\n').trim() : '';
+}
+
+function compactProgressiveParts(parts: string[]): string[] {
+  const compacted: string[] = [];
+
+  for (const part of parts) {
+    const current = normalizeProgressiveText(part);
+    if (!current) continue;
+
+    const previous = compacted.at(-1);
+    if (!previous) {
+      compacted.push(part);
+      continue;
+    }
+
+    const normalizedPrevious = normalizeProgressiveText(previous);
+    if (!normalizedPrevious) {
+      compacted[compacted.length - 1] = part;
+      continue;
+    }
+
+    if (current === normalizedPrevious || normalizedPrevious.startsWith(current)) {
+      continue;
+    }
+
+    if (current.startsWith(normalizedPrevious)) {
+      compacted[compacted.length - 1] = part;
+      continue;
+    }
+
+    compacted.push(part);
+  }
+
+  return compacted;
+}
+
 /**
  * Extract displayable text from a message's content field.
  * Handles both string content and array-of-blocks content.
@@ -49,7 +87,7 @@ export function extractText(message: RawMessage | unknown): string {
         }
       }
     }
-    const combined = parts.join('\n\n');
+    const combined = compactProgressiveParts(parts).join('\n\n');
     result = combined.trim().length > 0 ? combined : '';
   } else if (typeof msg.text === 'string') {
     // Fallback: try .text field
@@ -85,7 +123,7 @@ export function extractThinking(message: RawMessage | unknown): string | null {
     }
   }
 
-  const combined = parts.join('\n\n').trim();
+  const combined = compactProgressiveParts(parts).join('\n\n').trim();
   return combined.length > 0 ? combined : null;
 }