downgrading ansi-regex version 4 to 3 - an arrow function was used in…

[iamsoorena]

since there was an arrow function used in strip-ansi version 4, next.js was throwing errors is versions 3+.
so we should either use the old version of strip-ansi or we should compile it.
more info about the problem of version 4 of strip-ansi is found here.

[ptomasroos]

Word. Experiencing the same thing! @timneutkens

[haydn]

Looks like this was fixed in #2860 and then reverted in 531d0a3.

[haydn]

If you're using Yarn you can work around this issue with:

  "resolutions": {
    "next/strip-ansi": "3.0.1"
  }

See: https://yarnpkg.com/lang/en/docs/selective-version-resolutions/

[iamsoorena]

@haydn thank you it worked really well. although it doesn't work in Development but it works like a charm in Production.

[timneutkens]

Applied a fix that didn't involve downgrading ansi-regex. It was being build into the production bundle, even though it wasn't being used (only in development). So this error is going in production mode. @iamsoorena has confirmed it works on slack 👍

[ptomasroos]

In what version @timneutkens ?

[timneutkens]

@ptomasroos next@canary

[mattywong]

@timneutkens doesn't seem to have been fixed in next@canary, still getting the ansiregex syntax error (arrow function) running with a custom server, so not sure if it's because of that?

[iamsoorena]

@mattywong Did you try it in production environment?
because the problem hasn't been resolved in development environment yet.

[mattywong]

@timneutkens my bad, it's working fine now in production thanks!

[i8ramin]

So this still doesn't solve the "Fetch as Google / PageSpeed" problem. ie,
https://developers.google.com/speed/pagespeed/insights/?url=https%3A%2F%2Fdeploy-preview-38--candidco.netlify.com%2F

[DominikLevitsky]

The problem still persists.

[david-genger]

Anyone, please help, I just migrated to next on the promise of good SEO and now everything is in the air :-(
I can't use the solution from @timneutkens as I am using NPM.

https://developers.google.com/speed/pagespeed/insights/?url=https%3A%2F%2Fcompareali.com%2F

Runing NestJs version 6..

[david-genger]

I see that the Zeit.co website it's working properly! @rauchg what are you and your team doing in order it should work?

[timneutkens]

Next by itself doesn't need polyfills by default, but you're most likely using an external library does.

Example of basic Next.js:
https://developers.google.com/speed/pagespeed/insights/?url=https%3A%2F%2Fcreate-next-example-app-fnevuusuhp.nextjs.org%2F&tab=mobile

The with-polyfills example shows how to configure polyfills as-needed:
https://github.com/zeit/next.js/tree/canary/examples/with-polyfills

Since you asked, this is the polyfills we add:

import fill from 'core-js/library/fn/array/virtual/fill'
import includes from 'core-js/library/fn/string/virtual/includes'
import repeat from 'core-js/library/fn/string/virtual/repeat'
import startsWith from 'core-js/library/fn/string/virtual/starts-with'
import assign from 'core-js/library/fn/object/assign'

// Some of the NPM packages we included, use following methods without polyfills.
// So, we need to include these polyfills.
// (This is only needed for IE11)
Array.prototype.fill = fill
String.prototype.includes = includes
String.prototype.repeat = repeat
String.prototype.startsWith = startsWith
Object.assign = assign

[david-genger]

@timneutkens so basically every web app will need different polyfills in order to be supported in Chrome 41, the version that Google Bot uses?