Weigh

A command line tool to check the bundle size of one or more browser compatible npm modules

Install

npm i -g weigh

Usage

Usage: weigh [<args>] <module1> [<module2>] [<moduleN>...]

Supports any module identifier on the format [@scope/]package[@version][/module.js]

  Options:
    --help, -h          Show this usage information

    --bundler -b        Which bundler to use. Can be one of
                          • `browserify` (default)
                          • `concat`

    --minifier, -m      Specify which JavaScript minifier to use. Can be either
                          • `uglify` for UglifyJS (default)
                          • `closure` for Closure Compiler
                          • `babili` for Babili
                          • `butternut` for Butternut

    --verbose, -v       Do a little more logging along the way

    --gzip-level, -g    Gzip compression level

    --no-minify         Don't minify

    --no-gzip           Don't gzip

    --uncompressed, -u  Shorthand for --no-minify --no-gzip

    --env               The value of process.env.NODE_ENV inside the bundle.
                        Defaults to `production`

    --output -o         Output final result to stdout. You may also want to
                        disable gzipping with --no-gzip
                        If browserify used for bundling, `fullpaths: true`
                        will be passed as an option to browserify, so that
                        e.g. `discify` can be used for further bundle
                        inspection

    --version           Output current version

    Examples:
      weigh lodash
      weigh lodash/map
      weigh lodash@latest/map
      weigh @myorg/mypkg
      weigh @myorg/mypkg@latest
      weigh @myorg/mypkg/foo/bar.js
      weigh @myorg/mypkg@latest/foo/bar.js
      weigh @myorg/mypkg@2.1.4/foo/bar.js
      weigh ./path/to/foo/bar.js
      weigh /absolute/path/to/foo/bar.js
      weigh . (resolved module from cwd)

Example:

$ weigh lodash

Outputs:

Downloading lodash, this may take a little while…
Downloaded 1 package(s)

Weighing lodash…

Approximate weight of lodash:
  Uncompressed: ~412.11 kB
  Minified (uglify): 51.61 kB
  Minified and gzipped (level: default): ~18.82 kB

Note: By default weigh uses browserify under the hood to bundle the module, and adds envify as a global transform, with NODE_ENV set to production

This means weigh will report the size of a production build for modules that does code branching based on process.env.NODE_ENV

For example compare:

$ weigh redux
Approximate weight of redux:
  Uncompressed: 28.5 kB
  Minified (uglify): 7.82 kB
  Minified and gzipped (level: default): 2.73 kB

...with:

$ weigh redux --development
Approximate weight of redux:
  Uncompressed: 28.5 kB
  Minified (uglify): 9.23 kB
  Minified and gzipped (level: default): 3.36 kB

Inspecting the final result

You can output the compiled bundle for further inspection using --output (or -o) command line option. Note: By default this will output the gzipped result, so you'd probably want to use the --no-gzip flag

This will just pipe generated the bundle to stdout, which also enables further bundle size breakdown e.g. using hughsk/disc.

For example:

weigh --output rxjs --no-gzip | discify --open

Some more examples of supported module formats

weigh lodash
weigh lodash/collection/map
weigh lodash@latest/collection/map
weigh @myorg/mypkg
weigh @myorg/mypkg@latest
weigh @myorg/mypkg/foo/bar.js
weigh @myorg/mypkg@latest/foo/bar.js
weigh @myorg/mypkg@2.1.4/foo/bar.js
weigh ./path/to/foo/bar.js
weigh /absolute/path/to/foo/bar.js
weigh . (module in cwd)

License

MIT