Unexpected token: operator (>) from UglifyJs

[Zysce]

I have 2 Vue-Cli webpack projects (ClientApp and Lib).
Lib is my components library (shared with other projects)

Problem

When I build my project ClientApp npm run build, I have the following error:

ERROR in static/js/app.d08a24ce0e8d0438ce68.js from UglifyJs
Unexpected token: operator (>) [C:/.../Lib/src/tools/escape-key.js:3,0][static/js/app.d08a24ce0e8d0438ce68.js:17468,38]

Questions

It seems like the error comes from an arrow function in the file escape-key.js.
This is ES6 syntax and UglifyJS can't parse this.
Shouldn't Babel go first, before Uglify?
Note that is works well with *.vue files.

Project structure

ClientApp
   | - build
   | - config
   | - src
       | - App.Vue // import EscapeKey from '~lib/tools/escape-key';

Lib
  | -src
     | - tools
         | - escape-key.js

ClientApp's webpack.base.conf.js file

Note there is an alias to Lib.

resolve: {
    extensions: ['.js', '.vue', '.json'],
    alias: {
      '@': resolve('src'),
      '~lib': path.join(__dirname, '../../lib/src'),
    }
  },

Please feel free to ask for more details if required.

[posva]

Please ask questions on the forum or StackOverflow. It'll be easier if you share your project code too