Use of npm module with Uglify causes error about iso-639-1

[meikidd]

Thanks for reporting this issue, could you share your webpack config file? I am also using webpack uglify plugin in my project but haven't encountered this error.

[ragesoss]

Here's the main webpack config file: https://github.com/WikiEducationFoundation/WikiEduDashboard/blob/master/gulp/tasks/webpack.js

Also possibly relevant: https://github.com/WikiEducationFoundation/WikiEduDashboard/blob/master/.babelrc

It's possibly that different babel config would fix the problem, as I think it's caused by ES6 syntax that Uglify doesn't handle... so if it's already transpiled to ES5, I've read that it should work.

Interestingly, the error doesn't cause any noticeable effects in the development environment — things all work as expected, including the use of this module, and there are no console errors — but the browser tests all fail.

[meikidd]

I think we include different version of UglifyJsPlugin,

In my webpack config file:

const UglifyJsPlugin = require('uglifyjs-webpack-plugin');

new UglifyJsPlugin({ ... })

In your config file #L54:

new webpack.optimize.UglifyJsPlugin({ ... })

The bellow explaination is from webpack-contrib/uglifyjs-webpack-plugin

webpack < v4.0.0 currently contains v0.4.6 of this plugin under webpack.optimize.UglifyJsPlugin as an alias.

I guess the error will disappear when you update the UglifyJsPlugin module.