IE11 throw Promise is undefined

[silaike]

Description

IE11 throw Promise is undefined

Expected behavior

Promise should be polyfilled.

Actual behavior

IE11 throws any error in console.

Environment

React Hot Loader version: 4.13.0

Reproducible Demo

it works fine in 4.12.x

[theKashey]

React-Hot-Loader is not expected to work with IE11, as the latter was deprecated roughly a year ago.
However, there is question about polyfill and it's presence in your codebase

• if it is missing - please add, library cannot do it
• if it is not missing, but by any reason not applied before RHL uses Promises - that's a bug.

[silaike]

polyfill is not missing in my code, it works fine in React Hot Loader version: 4.12.x.

in React Hot Loader version: 4.13.0, it's throwing the error here:

react-hot-loader/src/global/generation.js

Line 59 in 69b9d48

Promise.resolve(incrementHot()).then(() => setTimeout(decrementHot, 0));

[theKashey]

That code was not changed in a last few years, the question is why this code is called before(?) polyfill initilization (so that sounds like a bug)

[moonjoungyoung]

I am having same issue.

webpack.config.js

    entry: [
      '@babel/polyfill',
      path.resolve(__dirname, './src/global/scripts/polyfills.js'),
      'react-hot-loader/patch',
      path.resolve(__dirname, './src/index.js'),
    ],

[theKashey]

please double-check that RHL is not patching your polyfills. Or even easier - check the stack trace of the error to find the file it's originated, and the position of that file in entry scripts.