Chapter 13: Adding return { message: string } breaks build due to invalid typing

[riceboyler]

According to the types as defined in FormHTMLAttributes (in react/index.d.ts), the action property ((formData: FormData) => can only either return a void or a Promise<void>. By adding a return object as indicated in the "Reveal the Solution" sections, it breaks next build because the typing is invalid.

I believe these actions are expecting not to actually return anything, hence the errors. I had to change my code to instead throw a new Error and console.error rather than returning { message: 'Whatever message to return here' } in order to fix my builds.

I don't know if this is something that changed as of React v19.0 stable or not, but returning an object appears to no longer be supported.

[riceboyler]

Digging further into Chapter 14, I think the issue is that the addition of the {message: string} response is being added too early. Once you start using useActionState, then the expected response changes to be able to accept a response object from the form actions.

[leerob]

Thank you! I will fix this