TypeError: Cannot assign to read only property 'children' of object '#<Object>'

[atdrago]

Hello! I wanted to let you know about an issue we ran into in one of our projects that was using next-boost.

Lots of details can be found here in this issue: vercel/next.js#24783 (comment)

I've created an example reproduction case here: atdrago/repro-24783@1ea71f6

The error is below, and goes away when setting NODE_ENV to production in our .env.production file, so it appears that, by default, next-boost runs with a NODE_ENV of development. This is different from next start.

The actual error we see in production is:

TypeError: Cannot assign to read only property 'children' of object '#'
at /path/to/project/.next/server/chunks/6859.js:740:29
at /path/to/project/node_modules/react/cjs/react.development.js:1067:17
at mapIntoArray (/path/to/project/node_modules/react/cjs/react.development.js:964:23)
at mapIntoArray (/path/to/project/node_modules/react/cjs/react.development.js:1004:23)
at Object.mapChildren [as map] (/path/to/project/node_modules/react/cjs/react.development.js:1066:3)
at Head.makeStylesheetInert (/path/to/project/.next/server/chunks/6859.js:732:36)
at Head.render (/path/to/project/.next/server/chunks/6859.js:789:23)
at processChild (/path/to/project/node_modules/react-dom/cjs/react-dom-server.node.development.js:3450:18)
at resolve (/path/to/project/node_modules/react-dom/cjs/react-dom-server.node.development.js:3270:5)
at ReactDOMServerRenderer.render (/path/to/project/node_modules/react-dom/cjs/react-dom-server.node.development.js:3753:22)

[rjyo]

Will there be errors when using getServerSideProps?

next-boost is meant to be a replacement for getStaticProps without specifying all possible routes and I have never used them together.

[atdrago]

We haven't seen any errors using getServerSideProps.

It may be worth mentioning in the README if getStaticProps is not meant to be used with next-boost. Is this documented somewhere?

In my mind though, the bigger concern are the mentions of react.development.js and react-dom-server.node.development.js in the stack trace. Using it as a drop-in replacement for next start, when we don't explicitly set NODE_ENV=production, it seems next-boost runs in development mode. If we do explicitly set NODE_ENV=production in our .env file (we shouldn't need to do this), the error goes away. Any ideas why?

[rjyo]

Thanks for the advice. I'll take a look at the env thing.

In our setups, we have the NODE_ENV=production in every startup script and thus haven't run into this problem.

[rjyo]

Please check this release.

https://github.com/rjyo/next-boost/releases/tag/v0.10.2