Follow-up work to Modern Mode

[Timer]

This is an umbrella issue tracking follow-up work for Modern Mode.

• Add production tests for IE, FF, etc
• Change polyfilling behavior for modern bundles
• Remove ESM plugin in favor of 3rd compiler when node_modules/ is compiled

[radeno]

Hi, this is an issue what we are figuring out.
Our idea is use two (3 because one is SSR) parallel separate processes.

Every process target could be defined as browserslist definition. https://github.com/browserslist/browserslist#configuring-for-different-environments

Currently SSR results are stored into server folder. It is straight forward, because targets is defined as node current. That is good if all instances have same Node version.

Similar behavior should be for two others targets. Legacy and Modern.

Legacy and Modern can be separated with own manifest files (build-manifest.json), builded into custom folders or append suffix to files naming. And then merged into final manifest files.

Main Pro: Independent and separated building
Main Con: Longer building time

[ReinoutStevens]

Hey,

Don't know if this is the correct place to post this, so feel free to remove it or direct me to the correct one :).
We tested the experimental modern flag, which is working fine on all browsers except IE11. For IE11 both the module and regular js is downloaded. IE11 stops being a SPA, so I assume it cannot properly handle the module file and fails executing it.
For all the other browsers, including Edge, we see the behavior we expect.

[timneutkens]

@atcastle @janicklas-ralph

[janicklas-ralph]

Hey @ReinoutStevens, this is a known behavior in IE11 where the browser downloads both the type=module and nomodule scripts but executes only the nomodule script.
Here is a good discussion regarding the issue and here is a summary of all the browsers that don't work as expected when dealing with type=module scripts.

So both scripts being loaded is expected and I presume your issue isn't related to that.
Does the site work fine on IE 11 without the modern flag enabled?

[ReinoutStevens]

Hey @janicklas-ralph thanks for the reply. It appears some part got broken in IE11 with upgrading from NextJS 9.0.6 to 9.1.5, and not the modern flag ( both happened at the same time here ). Thank you for your time.

[ReinoutStevens]

For completeness: the update of the url polyfill in v91.5 broke some link logic on our side, which has been resolved. Testing IE11 with the modern flag now has the correct behavior. Thank you for your time.

[Timer]

Closing this as it has been mostly accomplished.

[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.