Prismic.io CMS example doesn't work with latest version of next.js

[brunocrosier]

As per title, the example works great with version 9.2.3-canary.26 but breaks with 9.4.0

Errors are quite vague so hard to pinpoint why - anybody have any ideas?

[jamesmosier]

What are the errors? 🤔

[brunocrosier]

On homepage:

Unhandled Runtime Error
Error: Error serializing `.preview` returned from `getStaticProps` in "/".
Reason: `undefined` cannot be serialized as JSON. Please use `null` or omit this value all together.

On posts page:

Error: Error serializing `.preview` returned from `getStaticProps` in "/posts/[slug]".
Reason: `undefined` cannot be serialized as JSON. Please use `null` or omit this value all together.

When I downgrade back to 9.2.3-canary.26 it works 🤷‍♂️

[brunocrosier]

Interestingly, if I comment out the preview line here then it works (but doesn't work with preview mode obviously)

export async function getStaticProps({ preview, previewData }) {
  const allPosts = await getAllPostsForHome(previewData)
  return {
    props: { 
      // preview,
       allPosts },
  }
}

[b-bot]

#12806

[brunocrosier]

Ah good, I'm not the only one :)

[Timer]

Fix is up in this PR: #12840

Be sure you set preview to be false by default:

export async function getStaticProps({ preview = false, previewData = null }) {
  // ...
}