Description

A JS minifier with more aggressive set of default options. Options are configurable in your project's package.json.

Interesting side effect This package increases security by removing part of your server side code which is normally included by the Meteor's standard minifier.

Usage

meteor remove standard-minifier-js
meteor add ssrwpo:uglifyjs2

Configuration

Default options

The following default options are activated:

uglifyjs2: {
  deadCodes: [
    '_meteor.Meteor.isServer',
    'Meteor.isServer'
  ],
  fileRemoval: [
    'packages/ddp-server.js',
    'packages/shell-server.js',
    'packages/ssrwpo_uglifyjs2.js'
  ],
  packageDebug: false,
  options: {
    fromString: true,
    compress: {
      properties: true,
      dead_code: true,
      drop_debugger: true,
      conditionals: true,
      comparisons: true,
      evaluate: true,
      booleans: true,
      loops: true,
      unused: true,
      hoist_funs: true,
      if_return: true,
      join_vars: true,
      cascade: true,
      collapse_vars: true,
      negate_iife: true,
      pure_getters: true,
      drop_console: true,
      keep_fargs: false,
      keep_fnames: false,
      passes: 2,
      global_defs: {
        UGLYFYJS_DEAD: false
      }
    }
  }
}

Dead code elimination

deadCodes is a list of Strings is used for text replacement as a global definition transformed into UGLYFYJS_DEAD allowing minifications with dead code removal. This acts as macro for code removal in your project.

In your package.json, add the deadCodes option to additional dead code removals:

"uglifyjs2": {
  ...
  "deadCodes": ["Meteor.isServer", ...],
  ...
}

By default, the list only contains: ['Meteor.isServer'].

UglifyJS2 options

Overwrite the default options to add or remove UglifyJS2's options.

In your package.json, add the options for tweaking UglifyJS2's options:

"uglifyjs2": {
  ...
  "options": {
    "fromString": true,
    "compress": {
      ...
      "properties": false,
      ...
    }
  }
  ...
}

⚠️ Meteor relies on text analysis when using UglifyJS2. Therefore, removing the fromString option leads to unexpected results.

Development minification

Meteor's standard minifier skip minification while in development. As dead code removal could affect your project's behavior, this package allows you to minify your code while developping.

In your package.json, add the development option to activate minification while in development mode:

"uglifyjs2": {
  ...
  "development": true,
  ...
}

Package debug options

This adds some debug informations while processing production build. It helps tracking the files that will get included into the web bundle JS file.

For activating it, simply add the packageDebug option in your package.json.

"uglifyjs2": {
  ...
  "packageDebug": true,
  ...
}

File removals

Meteor injects files in the client that doesn't belong to the client. This is used by Meteor to display informations on used packages in the server. Removing these informations increase security and removes some unecessary lost bytes.

Some defaults files are removed automatically with this package and you can tweak these removals using fileRemoval options in your package.json.

"uglifyjs2": {
  ...
  "fileRemoval": [
    "packages/ddp-server.js",
    "packages/shell-server.js",
    "packages/ssrwpo_uglifyjs2.js"
  ],
  ...
}

Aggressive minification

By default, minification is done file by file. Aggressive minification aggregates all files and then apply the minification allowing UglifyJS2 to go a little bit further in its optimization.

Turned off by default, this option can be added using the aggressive flag in your package.json.

"uglifyjs2": {
  ...
  "aggressive": true,
  ...
}

Package development

Exported symbols

This package exports a function loadPackageJson that parses the content of then NPM's package.json file of a Meteor project.

Dependencies & demo project

At the root of the repository:

yarn install
cd demo
yarn install
# Launch the demo in development mode
yarn dev
# Launch the demo in production mode
yarn prod

Tips

• My build process is stucked at "Minifying app code": meteor reset.
• Start with a small project when choosing your options.
• Don't add reduce_vars as option as it prevents Meteor from starting.
• Use the default options as a canevas for experimenting additional UglifyJS2 options.

Links

• UglifyJS2