fix: generate response button disappear on tool call (#5988)

* fix: generate a response button should appear when an incomplete tool call message is present

* fix: wording

* fix: do not send duplicate messages on regenerating

* fix: tests

web-app/src/containers/dialogs/LoadModelErrorDialog.tsx

@@ -52,7 +52,7 @@ export default function LoadModelErrorDialog() {
             <div>
               <DialogTitle>{t('common:error')}</DialogTitle>
               <DialogDescription className="mt-1 text-main-view-fg/70">
-                Failed to load model
+                Something went wrong
               </DialogDescription>
             </div>
           </div>

web-app/src/hooks/useChat.ts

@@ -247,8 +247,7 @@ export const useChat = () => {
           messages,
           currentAssistant?.instructions
         )
-
+        if (troubleshooting) builder.addUserMessage(message)
-        builder.addUserMessage(message)
 
         let isCompleted = false
 

web-app/src/lib/__tests__/messages.test.ts

@@ -1,3 +1,4 @@
+import { describe, it, expect } from 'vitest'
 import { CompletionMessagesBuilder } from '../messages'
 import { ThreadMessage } from '@janhq/core'
 import { ChatCompletionMessageToolCall } from 'openai/resources'
@@ -66,7 +67,10 @@ describe('CompletionMessagesBuilder', () => {
 
     it('should normalize assistant message content', () => {
       const messages: ThreadMessage[] = [
-        createMockThreadMessage('assistant', '<think>Let me think...</think>Hello there!'),
+        createMockThreadMessage(
+          'assistant',
+          '<think>Let me think...</think>Hello there!'
+        ),
       ]
 
       const builder = new CompletionMessagesBuilder(messages)
@@ -78,14 +82,19 @@ describe('CompletionMessagesBuilder', () => {
 
     it('should preserve user message content without normalization', () => {
       const messages: ThreadMessage[] = [
-        createMockThreadMessage('user', '<think>This should not be normalized</think>Hello'),
+        createMockThreadMessage(
+          'user',
+          '<think>This should not be normalized</think>Hello'
+        ),
       ]
 
       const builder = new CompletionMessagesBuilder(messages)
       const result = builder.getMessages()
 
       expect(result).toHaveLength(1)
-      expect(result[0].content).toBe('<think>This should not be normalized</think>Hello')
+      expect(result[0].content).toBe(
+        '<think>This should not be normalized</think>Hello'
+      )
     })
 
     it('should handle messages with empty content', () => {
@@ -104,7 +113,9 @@ describe('CompletionMessagesBuilder', () => {
     it('should handle messages with missing text value', () => {
       const message: ThreadMessage = {
         ...createMockThreadMessage('user', ''),
-        content: [{ type: 'text' as any, text: { value: '', annotations: [] } }],
+        content: [
+          { type: 'text' as any, text: { value: '', annotations: [] } },
+        ],
       }
 
       const builder = new CompletionMessagesBuilder([message])
@@ -129,16 +140,15 @@ describe('CompletionMessagesBuilder', () => {
       })
     })
 
-    it('should add multiple user messages', () => {
+    it('should not add consecutive user messages', () => {
       const builder = new CompletionMessagesBuilder([])
 
       builder.addUserMessage('First message')
       builder.addUserMessage('Second message')
 
       const result = builder.getMessages()
-      expect(result).toHaveLength(2)
+      expect(result).toHaveLength(1)
-      expect(result[0].content).toBe('First message')
+      expect(result[0].content).toBe('Second message')
-      expect(result[1].content).toBe('Second message')
     })
 
     it('should handle empty user message', () => {
@@ -171,7 +181,10 @@ describe('CompletionMessagesBuilder', () => {
     it('should add assistant message with refusal', () => {
       const builder = new CompletionMessagesBuilder([])
 
-      builder.addAssistantMessage('I cannot help with that', 'Content policy violation')
+      builder.addAssistantMessage(
+        'I cannot help with that',
+        'Content policy violation'
+      )
 
       const result = builder.getMessages()
       expect(result).toHaveLength(1)
@@ -196,7 +209,11 @@ describe('CompletionMessagesBuilder', () => {
         },
       ]
 
-      builder.addAssistantMessage('Let me check the weather', undefined, toolCalls)
+      builder.addAssistantMessage(
+        'Let me check the weather',
+        undefined,
+        toolCalls
+      )
 
       const result = builder.getMessages()
       expect(result).toHaveLength(1)
@@ -282,19 +299,21 @@ describe('CompletionMessagesBuilder', () => {
       const threadMessages: ThreadMessage[] = [
         createMockThreadMessage('user', 'Hello'),
       ]
-      const builder = new CompletionMessagesBuilder(threadMessages, 'You are helpful')
+      const builder = new CompletionMessagesBuilder(
+        threadMessages,
+        'You are helpful'
+      )
 
       builder.addUserMessage('How are you?')
       builder.addAssistantMessage('I am well, thank you!')
       builder.addToolMessage('Tool response', 'call_123')
 
       const result = builder.getMessages()
-      expect(result).toHaveLength(5)
+      expect(result).toHaveLength(4)
       expect(result[0].role).toBe('system')
       expect(result[1].role).toBe('user')
-      expect(result[2].role).toBe('user')
+      expect(result[2].role).toBe('assistant')
-      expect(result[3].role).toBe('assistant')
+      expect(result[3].role).toBe('tool')
-      expect(result[4].role).toBe('tool')
     })
 
     it('should return the same array reference (not immutable)', () => {
@@ -317,7 +336,9 @@ describe('CompletionMessagesBuilder', () => {
     it('should remove thinking content from the beginning', () => {
       const builder = new CompletionMessagesBuilder([])
 
-      builder.addAssistantMessage('<think>Let me analyze this...</think>The answer is 42.')
+      builder.addAssistantMessage(
+        '<think>Let me analyze this...</think>The answer is 42.'
+      )
 
       const result = builder.getMessages()
       expect(result[0].content).toBe('The answer is 42.')
@@ -326,7 +347,9 @@ describe('CompletionMessagesBuilder', () => {
     it('should handle nested thinking tags', () => {
       const builder = new CompletionMessagesBuilder([])
 
-      builder.addAssistantMessage('<think>First thought<think>Nested</think>More thinking</think>Final answer')
+      builder.addAssistantMessage(
+        '<think>First thought<think>Nested</think>More thinking</think>Final answer'
+      )
 
       const result = builder.getMessages()
       expect(result[0].content).toBe('More thinking</think>Final answer')
@@ -335,7 +358,9 @@ describe('CompletionMessagesBuilder', () => {
     it('should handle multiple thinking blocks', () => {
       const builder = new CompletionMessagesBuilder([])
 
-      builder.addAssistantMessage('<think>First</think>Answer<think>Second</think>More content')
+      builder.addAssistantMessage(
+        '<think>First</think>Answer<think>Second</think>More content'
+      )
 
       const result = builder.getMessages()
       expect(result[0].content).toBe('Answer<think>Second</think>More content')
@@ -362,16 +387,22 @@ describe('CompletionMessagesBuilder', () => {
     it('should handle unclosed thinking tags', () => {
       const builder = new CompletionMessagesBuilder([])
 
-      builder.addAssistantMessage('<think>Unclosed thinking tag... Regular content')
+      builder.addAssistantMessage(
+        '<think>Unclosed thinking tag... Regular content'
+      )
 
       const result = builder.getMessages()
-      expect(result[0].content).toBe('<think>Unclosed thinking tag... Regular content')
+      expect(result[0].content).toBe(
+        '<think>Unclosed thinking tag... Regular content'
+      )
     })
 
     it('should handle thinking tags with whitespace', () => {
       const builder = new CompletionMessagesBuilder([])
 
-      builder.addAssistantMessage('<think>  \n  Some thinking  \n  </think>  \n  Clean answer')
+      builder.addAssistantMessage(
+        '<think>  \n  Some thinking  \n  </think>  \n  Clean answer'
+      )
 
       const result = builder.getMessages()
       expect(result[0].content).toBe('Clean answer')
@@ -382,10 +413,16 @@ describe('CompletionMessagesBuilder', () => {
     it('should handle complex conversation flow', () => {
       const threadMessages: ThreadMessage[] = [
         createMockThreadMessage('user', 'What is the weather like?'),
-        createMockThreadMessage('assistant', '<think>I need to call weather API</think>Let me check the weather for you.'),
+        createMockThreadMessage(
+          'assistant',
+          '<think>I need to call weather API</think>Let me check the weather for you.'
+        ),
       ]
 
-      const builder = new CompletionMessagesBuilder(threadMessages, 'You are a weather assistant')
+      const builder = new CompletionMessagesBuilder(
+        threadMessages,
+        'You are a weather assistant'
+      )
 
       // Add tool call and response
       const toolCalls: ChatCompletionMessageToolCall[] = [
@@ -399,9 +436,18 @@ describe('CompletionMessagesBuilder', () => {
         },
       ]
 
-      builder.addAssistantMessage('Calling weather service...', undefined, toolCalls)
+      builder.addAssistantMessage(
-      builder.addToolMessage('{"temperature": 72, "condition": "sunny"}', 'call_weather')
+        'Calling weather service...',
-      builder.addAssistantMessage('<think>The weather is nice</think>The weather is 72°F and sunny!')
+        undefined,
+        toolCalls
+      )
+      builder.addToolMessage(
+        '{"temperature": 72, "condition": "sunny"}',
+        'call_weather'
+      )
+      builder.addAssistantMessage(
+        '<think>The weather is nice</think>The weather is 72°F and sunny!'
+      )
 
       const result = builder.getMessages()
 

web-app/src/lib/messages.ts

@@ -26,7 +26,7 @@ export class CompletionMessagesBuilder {
               content:
                 msg.role === 'assistant'
                   ? this.normalizeContent(msg.content[0]?.text?.value || '.')
-                  : (msg.content[0]?.text?.value || '.'),
+                  : msg.content[0]?.text?.value || '.',
             }) as ChatCompletionMessageParam
         )
     )
@@ -37,6 +37,10 @@ export class CompletionMessagesBuilder {
    * @param content - The content of the user message.
    */
   addUserMessage(content: string) {
+    // Ensure no consecutive user messages
+    if (this.messages[this.messages.length - 1]?.role === 'user') {
+      this.messages.pop()
+    }
     this.messages.push({
       role: 'user',
       content: content,

web-app/src/routes/threads/$threadId.tsx

@@ -39,7 +39,7 @@ function ThreadDetail() {
   const lastScrollTopRef = useRef(0)
   const { currentThreadId, setCurrentThreadId } = useThreads()
   const { setCurrentAssistant, assistants } = useAssistant()
-  const { setMessages } = useMessages()
+  const { setMessages, deleteMessage } = useMessages()
   const { streamingContent } = useAppState()
   const { appMainViewBgColor, chatWidth } = useAppearance()
   const { sendMessage } = useChat()
@@ -221,8 +221,23 @@ function ThreadDetail() {
   // used when there is a sent/added user message and no assistant message (error or manual deletion)
   const generateAIResponse = () => {
     const latestUserMessage = messages[messages.length - 1]
-    if (latestUserMessage?.content?.[0]?.text?.value) {
+    if (
+      latestUserMessage?.content?.[0]?.text?.value &&
+      latestUserMessage.role === 'user'
+    ) {
       sendMessage(latestUserMessage.content[0].text.value, false)
+    } else if (latestUserMessage?.metadata?.tool_calls) {
+      // Only regenerate assistant message is allowed
+      const threadMessages = [...messages]
+      let toSendMessage = threadMessages.pop()
+      while (toSendMessage && toSendMessage?.role !== 'user') {
+        deleteMessage(toSendMessage.thread_id, toSendMessage.id ?? '')
+        toSendMessage = threadMessages.pop()
+      }
+      if (toSendMessage) {
+        deleteMessage(toSendMessage.thread_id, toSendMessage.id ?? '')
+        sendMessage(toSendMessage.content?.[0]?.text?.value || '')
+      }
     }
   }
 
@@ -232,7 +247,10 @@ function ThreadDetail() {
 
   const showScrollToBottomBtn = !isAtBottom && hasScrollbar
   const showGenerateAIResponseBtn =
-    messages[messages.length - 1]?.role === 'user' && !streamingContent
+    (messages[messages.length - 1]?.role === 'user' ||
+      (messages[messages.length - 1]?.metadata &&
+        'tool_calls' in (messages[messages.length - 1].metadata ?? {}))) &&
+    !streamingContent
 
   return (
     <div className="flex flex-col h-full">