Uglify SyntaxError: Unexpected token: punc ())

Question

I am trying to use gulp in order to minify a folder containing JS files. However, one of the files has the above error, preventing it from being minified.

I managed

Answer 1

// Update

From the comments ~ @imolit

 v2.0.0 (2018-09-14) - BREAKING CHANGES (link)

Switch back to uglify-js (uglify-es is abandoned, if you need uglify ES6 code please use terser-webpack-plugin).

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Original answer before the update...

I hope you can get inspired by this solution which works with webpack. (link below)

Simply teach UglifyJS ES6

There are two versions of UglifyJS - ES5 and ES6 (Harmony), see on git
ES5 version comes by default with all the plugins, but if you install a Harmony version explicitly, those plugins will use it instead.

package.json

"uglify-js": "git+https://github.com/mishoo/UglifyJS2.git#harmony"

or

npm install --save uglify-js@github:mishoo/UglifyJS2#harmony

yarn add git://github.com/mishoo/UglifyJS2#harmony --dev

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Webpack

To use it with webpack install also the webpack plugin

npm install uglifyjs-webpack-plugin --save-dev

yarn add uglifyjs-webpack-plugin --dev

then import the manually installed plugin

var UglifyJSPlugin = require('uglifyjs-webpack-plugin');

and replace it in code

-  new webpack.optimize.UglifyJsPlugin({ ... })
+  new UglifyJSPlugin({ ... })

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For more webpack info (Installation/Usage) see https://github.com/webpack-contrib/uglifyjs-webpack-plugin#install