React-hot-loader: 4.3.12 breaks polyfills for IE11

[joacim-boive]

Description

Upgrading from 4.3.11 to 4.3.12 breaks polyfilling for IE11.

Expected behavior

It should continue to work. :)

Actual behavior

No error messages during build but polyfills stops working.
They seem to be in the code but not executing or something.

Environment

React Hot Loader version: 4.3.12
webpack 4.25.1
@babel/preset-env 7.1.5

Run these commands in the project folder and fill in their results:

1. node -v: 10.13.0
2. npm -v: 6.4.1

Then, specify:

1. Operating system: macOS Mojave
2. Browser and version: IE 11

Reproducible Demo

No repo at this time - sorry. :(

[skarjalainen]

This file:
https://github.com/gaearon/react-hot-loader/blob/master/src/proxy/createClassProxy.js
Uses string method that IE11 does not support:
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/startsWith

I see error in IE11 console:
SCRIPT438: Object doesn't support property or method 'startsWith'

[theKashey]

I'll release a fix tomorrow. It's to late for me to draft any release today.

[rgllm]

Hi @theKashey, any updates on this? Thanks.

[theKashey]

Fell free to upgrade to 4.4.0-1 (beta). It fixes this and another issues.

[rgllm]

Hi @theKashey,
just tested 4.4.0-1 (beta) and I confirm the issue is solved. However, it gives another error related to the Polyfill.
Console print.

[theKashey]

My bad, sorry

[rgllm]

Following on, @theKashey do you have any time expectations to solve this?

[theKashey]

🐢 tomorrow morning (GMT+10) 🐌
Sorry, was partially offline for two days.

[joacim-boive]

Any updates? :)

[pfftdammitchris]

Great find! This definitely should be the reason why my app on IE is getting this error.

[theKashey]

Sorry for delay. I wanted to release this change with another one, but (and this is the nature of RHL) even having all the tests green - it does not work in real. Trying to find problem...

[theKashey]

Fixed in "next", v4.5.1

[joacim-boive]

Works great so far! :)

[theKashey]

:sweet:
So let me just collect some feedback before releasing a new version.

[theKashey]

4.6.0 is no longer beta.