无法在webpack bundle js文件中删除注释

我一直试图在webpack捆绑的js文件中删除注释。
我尝试了几种方法，但它还没有工作，我收到的评论就像

I have been trying to strip comments in the webpack bundled js file. I have tried several methods but it's not working still and I get comments like

"/**\n * Copyright 2013-present, Facebook, Inc.\n * All rights reserved.\n *\n * This source code is licensed under the BSD-style license found in the\ ...

为此，捆绑的文件变得越来越大。目前大小为1.6mb。
我试过这个

For this the bundled file is getting huge. Currently huge at 1.6mb size. I have tried this

new webpack.optimize.UglifyJsPlugin({
        sourceMap: false,
        compress: {
            sequences: true,
            dead_code: true,
            conditionals: true,
            booleans: true,
            unused: true,
            if_return: true,
            join_vars: true,
            drop_console: true
        },
        mangle: {
            except: ['$super', '$', 'exports', 'require']
        },
        output: {
            comments: false
        }
    })

此

new webpack.optimize.UglifyJsPlugin({
        compress: { warnings: false },
        sourceMap: false,
        output: false
    })

同时将环境设置为生产

set NODE_ENV=production

请帮忙。
提前致谢。

I am not able to understand where I am wrong. Please help. Thanks in advance.