Preview Mode has getServerSideProps({ preview, previewData }) in dev builds, not production builds.

Bug report

Describe the bug

Preview Mode does not work correctly in production.

In development mode, /[…slug].js endpoint’s getServerSideProps(props) receives props preview and previewData as mentioned by documentation. In production mode, /[…slug].js endpoint’s getServerSideProps(props) does not receive those props, despite __next_preview_data and __prerender_bypass cookies present in the request.

To Reproduce

Steps to reproduce the behavior, please provide code snippets or a repository:

Setup preview mode per docs.

1. Build /[…slug].js endpoint that uses getServerSideProps({ params, preview, previewData }). This page should send preview and previewData as props to be rendered so you can see it working or not.
2. Start server in development mode
3. Hit your /api/preview endpoint.
4. Observe preview and previewData are present on your test page, as well as the preview mode cookies.
5. Clear your cookies.
6. Stop the server
7. Build for production.
8. Start the server in production mode
9. Hit your /api/preview endpoint again to start preview mode again.
10. Observe preview and previewData are NOT present on your test page, but the cookies are present.

Expected behavior

Development and production mode to actually behave the same instead of being completely broken in production builds.

System information

• OS: macOS 10.15.7
• Browser: Chrome stable
• Version of Next.js: 9.5.5
• Version of Node.js: 12.18.4

[sathovsepyan]

Hi @xiata. Did you find any solution for this? I’m facing the same problem.

[balazsorban44]

This issue has been automatically locked due to no recent activity. If you are running into a similar issue, please create a new issue with the steps to reproduce. Thank you.