Webpack UglifyJsPlugin doesn't work on OSX but does on Windows

Question

When I try to compile my webpack build on OSX it gives an weird error but on Windows not, also never occurred.

errored on '{': /* harmony default export */ __webpack_exports__["default"] = class {

Answer 1

If you're using webpack 2, chances are that you have a dependency to some module that has the jsnext:main configuration option to provide its code as ES6 modules. In these cases, webpack 2 uses them, which works fine, until you try to use Uglify, which can't deal with ES6 code.

You're probably excluding your node_modules from Babel loading, as well you should, but for this to work, you need to tell webpack explicitly to include this jsnext:main module.

I had this problem with preact-compat and solved it like this:

module: {
    rules: [
        {
            test: /\.js$/,
            loader: 'babel-loader',
            include: [
                path.resolve(__dirname, './src'),
                path.resolve(__dirname, './node_modules/preact-compat/src')
            ]
        }
    ]
}