// UglifyJs do not support ES6+, you can also use babel-minify for better treeshaking: https://github.com/babel/minify
new webpack.optimize.UglifyJsPlugin({
compress: {
warnings: false
},
sourceMap: config.build.productionSourceMap,
parallel: true
}),

{
test: /\.js$/,
loader: 'babel-loader',
include: [resolve('src'),
resolve('test'),resolve('/node_modules/iview/src'),resolve('/node_modules/iview/packages')]
},

// UglifyJs do not support ES6+, you can also use babel-minify for better treeshaking: https://github.com/babel/minify
// new webpack.optimize.UglifyJsPlugin({
// compress: {
// warnings: false
// },
// sourceMap: config.build.productionSourceMap,
// parallel: true
// }),
new UglifyJsPlugin({
// 使用外部引入的新版本的js壓縮工具
parallel: true,
uglifyOptions: {
ie8: false,
ecma: 6,
warnings: false,
mangle: true,
// debug false
output: {
comments: false,
beautify: false,
// debug true
},
compress: {
// 在UglifyJs刪除沒有用到的代碼時不輸出警告
warnings: false,
// 刪除所有的 `console` 語句
// 還可以兼容ie瀏覽器
drop_console: 
true,
// 內(nèi)嵌定義了但是只用到一次的變量
collapse_vars: 
true,
// 提取出出現(xiàn)多次但是沒有定義成變量去引用的靜態(tài)值
reduce_vars: 
true,
}
}
}),

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