Legal, License, Copyright comments should not be removed by default

[jnachtigall]

Steps to reproduce:

Version in package.json:

    "grunt-webpack": "^3.0.2",
    "uglifyjs-webpack-plugin": "^1.1.8",
    "webpack": "^3.10.0",
    "webpack-bundle-analyzer": "^2.9.2"

My webpack.config.js:

const path = require('path');
const webpack = require('webpack');
const UglifyJSPlugin = require('uglifyjs-webpack-plugin');
const BundleAnalyzerPlugin = require('webpack-bundle-analyzer')
  .BundleAnalyzerPlugin;

const config = {
  // entry: ["babel-polyfill", "./app/js"]
  entry: {
    // Further entry points can be added here
    // NB: If you add further ones, then you probably also want to move
    // dependencies like jQuery into their own bundle
    // see https://webpack.js.org/guides/code-splitting/#prevent-duplication

    // the babel-polyfill and fetch polyfill needs to be loaded only once,
    // hence only added to app.js which is executed on every page
    app: ['babel-polyfill', 'whatwg-fetch', './src/components/app.js'],
    resizer: ['./src/prototype-assets/viewport-resizer/main.js'],
    fractalmenuenhancer: [
      './src/prototype-assets/fractal-menu-enhancer/main.js'
    ]
  },
  module: {
    rules: [
      {
        test: /\.js$/,
        exclude: /node_modules/,
        use: {
          loader: 'babel-loader'
        }
      }
    ]
  },
  resolve: {
    extensions: ['*', '.js', '.jsx']
  },
  output: {
    filename: '[name].bundle.js',
    path: path.resolve(__dirname, 'public/js/')
  },
  plugins: [
    new webpack.EnvironmentPlugin({
      // pass 'development' unless process.env.NODE_ENV is defined to further tasks/loaders/babel
      NODE_ENV: 'development'
    })
  ]
};

// Extend config to use best, small build for prod and fast, big for dev
if (process.env.NODE_ENV === 'production') {
  config.devtool = 'source-map';
  config.plugins.push(
    new UglifyJSPlugin({
      sourceMap: true
    })
  );
  config.plugins.push(
    new BundleAnalyzerPlugin({
      analyzerMode: 'static',
      reportFilename: '../webpack-bundle-size-analyser.html',
      openAnalyzer: false
    })
  );
} else {
  config.devtool = 'eval-source-map';
}

module.exports = config;

Now in the ./src/components/app.js there are several 'vendor' libraries imported like: import $ from 'jquery';

Actual results:
When running npm run build which creates a uglified minimal bundle, then all comments are stripped.

For instance, jquery has this header which is not present any more in the uglified bundle:

/*!
 * jQuery JavaScript Library v3.3.1
 * https://jquery.com/
 *
 * Includes Sizzle.js
 * https://sizzlejs.com/
 *
 * Copyright JS Foundation and other contributors
 * Released under the MIT license
 * https://jquery.org/license
 *
 * Date: 2018-01-20T17:24Z
 */

Expected results:
Legal copyright comments should not be stripped by default. The comment at webpack/webpack#324 (comment) points out, that

it's intended that webpack preserves some comments. This is for legal reasons. By default comments with @license, @preserve or starting with /*! are preserved

At the moment this is not the case: By default all comments are stripped at the moment.

[jnachtigall]

Interestingly, the correct legal comments are successfully extracted when adding extractComments:

    new UglifyJSPlugin({
      sourceMap: true,
      extractComments: true
    })

Strange, that the comments are not preserved in the bundle itself.

[alexander-akait]

@jnachtigall Seems bug. Thanks for issue. PR welcome!

[julkue]

Is there any way to "downgrade" or similar in the meantime? I'd like to upgrade to Webpack v4, but I can't without license comments.

[alexander-akait]

@julmot tomorrow i fix this or you can do PR 👍

[alexander-akait]

Done in #250

[michael-ciniawsky]

Released in v1.2.4 🎉

[michael-ciniawsky]

https://status.npmjs.org/incidents/gbk5bjx1169j
npm/npm#20077

Resolved :)

[julkue]

Thanks @michael-ciniawsky So when does this come into Webpack itself? I'm not directly depending on this plugin:

[alexander-akait]

@julmot already in webpack https://github.com/webpack/webpack/blob/master/package.json#L24 just update cache (npm/yarn cache clear) and/or lock file

[andrevenancio]

Hi, I've been trying to follow the documentation and a few of the issues here, and I'm not sure this is actually working.

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

module.exports = {
    entry: path.resolve(__dirname, 'src/index.js'),
    output: {
        filename: 'production-2.js',
        path: path.resolve(__dirname, 'dist')
    },
    mode: 'production',
    optimization: {
        minimizer: [
            new UglifyJsPlugin({
                uglifyOptions: {
                    output: {
                        comments: true,
                    }
                },
                extractComments: true, // /(?:^!|@(?:license|preserve))/i
            })
        ]
    }
};

Shouldn't this in theory keep all comments and save them to the external file?

my package.json uses:

"uglifyjs-webpack-plugin": "^1.2.5",
"webpack": "^4.8.2",
"webpack-cli": "^2.1.3"

[alexander-akait]

@andrevenancio remove all options UglifyJsPlugin works right now as expected - doesn't remove legal comments

[andrevenancio]

Hey @evilebottnawi then I might be doing something wrong. cause I've been trying different options and so far no luck..

I've even went to my node_modules and comment the shit out of node_modules/uglifyjs-webpack-plugin/dist/index.js and the array that stores my comments is always empty [] (from: data.extractedComments)

Here's my code: https://github.com/andrevenancio/license-example/blob/master/webpack.production-2.js

[andrevenancio]

We've been trying to help fix an issue on gl-matrix (toji/gl-matrix#304) and hence my tests

[alexander-akait]

@andrevenancio what you want remove all comments or leave legal comments?

[andrevenancio]

Yeah, sorry I've been explaining this poorly.

Yeah I'm expecting to scrap all the comments except the ones tagged with @license on gl-matrix we're currently missing the license itself on our src/gl-matrix.js (which is the entry point for webpack/rollup. We can add that easily, but for my tests I'm expecting that at least one of this comments is kept .

The idea is to strip every comment except the license from our gl-matrix repo.

[alexander-akait]

@andrevenancio i.e. only with @license directive, yes?

[alexander-akait]

You can avoid set uglifyOptions.output.comments if you set extractComments (https://github.com/webpack-contrib/uglifyjs-webpack-plugin/blob/master/src/index.js#L46)

[andrevenancio]

yeah, the idea is to only keep whatever has @license in our source. I've tried having just extractComments: true and no luck. Can you pull the repo and try to run npm run prod2?

Its either a problem with webpack or I dont know.. If I run the packages specified here I can't keep the license

[alexander-akait]

Use extractComments: /@(?:license)/i? Also you can use extractComments: (node, comment) => { console.log(comment); return true; } to debug what comments parses. uglify has some problems with some comments mishoo/UglifyJS#2500

[andrevenancio]

Still no luck.

If I use the function and log the comments I can see a bunch of comments coming through (mainly the comments used to generate the docs (from node_modules/gl-matrix),

However if I try to use the regexp to validate the comment the regexp fails and no comment is added

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

module.exports = {
    entry: path.resolve(__dirname, 'src/index.js'),
    output: {
        filename: 'production-2.js',
        path: path.resolve(__dirname, 'dist')
    },
    mode: 'production',
    optimization: {
        minimizer: [
            new UglifyJsPlugin({
                // extractComments: /@(?:license)/i
                extractComments: (node, comment) => {
                    console.log('comment', String(comment).search(/@(?:license)/i));
                    /*console.log(comment); */
                    return String(comment).search(/@(?:license)/i) !== -1;
               }
            })
        ]
    }
};

[alexander-akait]

@andrevenancio just put here what you comments you have and what comments should be left and should be strip.

[andrevenancio]

This are the comments I've been trying to test against.

https://github.com/andrevenancio/license-example/blob/master/src/index.js

None of them pass the regexp.

[alexander-akait]

@andrevenancio looks like problem in uglify (i wrote about this above)

[andrevenancio]

I see... so its just a matter of waiting for uglify to resolve the bug you posted and hopefully then you'll update uglifyjs-webpack-plugin?... 😢

[alexander-akait]

@andrevenancio i think this bug never was solve due in arch problem inside uglify ast parser, but if they fixed, you need only update deps and lock file, I would suggest that you try switch to babel-minify. I near future i will release new minor version allow to use own minify function. It is can may help.

[xyzdata]

still bug

mishoo/UglifyJS#3210

[xyzdata]

So, I have to write license info by hands?

1. src

/**
 *
 * @author xgqfrms
 * @license MIT
 * @copyright xgqfrms
 *
 * @description HC
 * @augments
 * @example
 *
 */
(function(){
    doSomething();
})();

2. target

I just want to keep the license as the source.

/**
 *
 * @author xgqfrms
 * @license MIT
 * @copyright xgqfrms
 *
 * @description HC
 * @augments
 * @example
 *
 */
!function(){doSomething();}

3. result

lost license?

!function(){doSomething();}

mishoo/UglifyJS#2500 (comment)

[AlexandreBonneau]

Uglify still does not respect the @license, @preserve nor /*! tags in the comments, and removes all of them.

I tried comments: 'some' and no comments are kept.
Just to be sure, I tried comments: 'all' and all comments are kept.

This is the extract of the webpack configuration:

const webpackConfig = merge(baseWebpackConfig, {
    mode   : 'production',
    module : {
        rules: [ // Only activate the linting when building for the production
            {
                test   : /\.js$/,
                loader : 'eslint-loader',
                enforce: 'pre',
                include: [resolve('src'), resolve('test')],
                options: {
                    formatter: require('eslint-friendly-formatter'),
                },
            },
        ],
    },
    optimization: {
        minimizer   : [
            new UglifyJsPlugin({
                cache        : true,
                parallel     : true,
                sourceMap    : true,
                uglifyOptions: {
                    nameCache: {},
                    ie8      : false,
                    safari10 : true,
                    compress : { // see https://github.com/mishoo/UglifyJS2#compress-options
                        dead_code    : true,
                        drop_debugger: true,
                        keep_fnames  : false,
                        passes       : 4,
                    },
                    output   : { // See https://github.com/mishoo/UglifyJS2#output-options
                        beautify: false,
                        comments: 'some',
                    },
                    mangle   : { // see https://github.com/mishoo/UglifyJS2#mangle-options
                        keep_fnames: false,
                        toplevel   : true,
                    },
                }
            }),
        ],
    },
    devtool: '#source-map',
    output : {
        libraryTarget: 'umd',
        library      : 'AutoNumeric',
        filename     : 'autoNumeric.min.js',
        path         : resolve('dist'),
    },
    plugins: [],
});

Could you please re-open that bug?

[alexander-akait]

@AlexandreBonneau we just wrapper around uglify-js, please create issue in uglify-js repo if you think what some comments are removed/not removed (uglify-es if you use uglifyjs-webpack-plugin@1)