Jekyll Minify Js

Jekyll plugin that minifies JavaScript files with Terser after the site is written.

Features

Minifies all .js files from a configurable source directory.
Writes minified output into a configurable destination directory.
Generates source maps by default.
Falls back to copying the original file if minification fails.

Requirements

Ruby 3.1+
Jekyll 4.4+

Installation

Add the gem to your Jekyll site's Gemfile:

gem 'jekyll-minify-js'

Then install dependencies:

bundle install

Configuration

Add a minify_js section to _config.yml:

minify_js:
  enable: true
  entry_dir: js
  output_dir: js
  compress: true
  mangle: true
  source_map: true

Options

Option	Type	Default	Description
`enable`	boolean	`true`	Set to `false` to skip minification.
`entry_dir`	string	`js`	Directory inside your source site containing input JavaScript files.
`output_dir`	string	`js`	Directory inside `_site` where minified files are written.
`compress`	boolean	`true`	Enables Terser compression.
`mangle`	boolean	`true`	Enables Terser name mangling.
`source_map`	boolean	`true`	Generates `.map` files and appends `sourceMappingURL`.

How It Works

During Jekyll's post_write hook, the plugin:

Reads JavaScript files from entry_dir.
Minifies each file with Terser.
Writes the result to _site/output_dir.
Writes a source map when source_map is enabled.
Copies the original file if Terser raises an error for that file.

Directory structure example:

your-site/
  js/
    app.js
    vendor/
      search.js
  _site/
    js/
      app.js
      app.js.map
      vendor/
        search.js
        search.js.map

Example

If your source files live in assets/js and you want output in assets/js inside _site:

minify_js:
  entry_dir: assets/js
  output_dir: assets/js
  compress: true
  mangle: true
  source_map: true

Development

Install dependencies:

bundle install

Run checks:

bundle exec rubocop

Generate YARD documentation:

bundle exec yard doc lib/**/*.rb README.md

Check documentation coverage without generating HTML:

bundle exec yard stats lib/**/*.rb

License

Released under the MIT License. See LICENSE.txt.