appendResponseMessages function Type error

[tsuzaki430]

Description

Hi , thank you for using ai sdk, I feel good DX developing generative AI application.

I use appendResponseMessages function because of convert ResponseMessage to Message.
When I tried upgrade ai version 4.1.5 to 4.1.25 , I met the error.
I tried serveral versions.
[email protected] - @ai4.1.11 works expectedly.
But [email protected] - ai@latest(4.1.25) those message happens.
PR #4670 may depends about it.

it happens streamText onFinish happens error (not Linter error).

unhandledRejection:  TypeError: Cannot read properties of undefined (reading 'role') at onFinish 

 ⨯ unhandledRejection:  TypeError: Cannot read properties of undefined (reading 'role')
    at onFinish (src\app\api\aichat\general\route.ts:241:52)
  239 |             // responseにAIからの回答messages:Message[]が入っている
  240 |             // const uiMessages=convertToUIMessages(response.messages as Message[])
> 241 |             const uiMessages=appendResponseMessages({
      |                                                    ^
  242 |               messages:[] as Message[],
  243 |               responseMessages:response.messages,
  244 |             });

The parameter messages is empty array because I need the response only.

const uiMessages=appendResponseMessages({
  messages:[] as Message[],
  responseMessages:response.messages,
});

I hope this issue will be useful.

Code example

No response

AI provider

@ai-sdk/azure 1.1.9

Additional context

No response

[lgrammel]

@tsuzaki430 you need to provide the input messages to appendResponseMessages. We reconcile messages and it may be that the last message gets modified (no new message added).

[tsuzaki430]

@lgrammel Thank you for response and I fixed my code and this issue has solved.
I close this issue and thank you.