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

• 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.

• Ruby 3.1+
• Jekyll 4.4+

Add the gem to your Jekyll site's Gemfile:

gem 'jekyll-minify-js'

Then install dependencies:

bundle install

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

During Jekyll's post_write hook, the plugin:

1. Reads JavaScript files from entry_dir.
2. Minifies each file with Terser.
3. Writes the result to _site/output_dir.
4. Writes a source map when source_map is enabled.
5. 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

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

Install dependencies:

bundle install

Run checks:

bundle exec rubocop

Released under the MIT License. See LICENSE.txt.