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Duplicate core-js module in the app's prod bundle due to polyfilling

See original GitHub issue

Describe the bug

After upgrading next-i18next from version 0.18.1, I’ve started seeing two copies of core-js in my prod bundle. This may be related to the fact that it’s in next-i18next’s dependencies and is also because of @babel/polyfill in .babelrc (9c96479e).

Before / after:

The problem may be to do with the fact that core-js is now used as both an es module and a commonjs one by webpack when the app is built.

Occurs in next-i18next version

0.20.0…0.25.0

Steps to reproduce

Run bundle analyzer for the Next.js app

OS (please complete the following information)

Device: MBP 2017 15"
Browser: N/A

Additional context

Perhaps, polyfilling should be removed from the library completely – doing it only once on the app level ensures that it’s not done twice and so there are no duplicate items in the final bundle. As a replacement, the README could advise on what an app developer should do to support older browsers. Some thoughts are here: https://github.com/isaachinman/next-i18next/issues/107

Issue Analytics

State:
Created 5 years ago
Comments:10 (10 by maintainers)

Top GitHub Comments

1reaction

capellinicommented, Feb 3, 2019

polyfilling for that browser can be done on the app level rather than when building the library

I agree. I think that polyfilling and determining what browsers to support should be made at the app-level.

0reactions

isaachinmancommented, Feb 4, 2019

Fixed with 4bf9d37. Hoping to release this at the same time as the rollup work so that there won’t be a lapse in ES5 support.

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