@ampproject/rollup-plugin-closure-compiler

rollup-plugin-closure-compiler

Leverage Closure Compiler to minify and optimize JavaScript with Rollup.

Generally Closure Compiler will produce superior minification than other projects, but historically has been more difficult to use. The goal of this plugin is to reduce this friction.

Installation

npm install @ampproject/rollup-plugin-closure-compiler --save-dev

Usage

Invoke Closure Compiler from your Rollup configuration.

// rollup.config.js
import compiler from '@ampproject/rollup-plugin-closure-compiler';

export default {
  input: 'main.js',
  output: {
    file: 'bundle.js',
    format: 'iife',
  },
  plugins: [
    compiler(),
  ],
}

If you would like to provide additional flags and options to Closure Compiler, pass them via key-value pairs.

// rollup.config.js
import compiler from '@ampproject/rollup-plugin-closure-compiler';

export default {
  input: 'main.js',
  output: {
    file: 'bundle.js',
    format: 'iife',
  },
  plugins: [
    compiler({
      formatting: 'PRETTY_PRINT'
    }),
  ],
}

Code Splitting via Dynamic Imports

This plugin supports code splitting with Rollup's experimentalCodeSplitting feature. Enable code splitting in your Rollup configuration and each output bundle will be minified by Closure Compiler.

// rollup.config.js
import compiler from '@ampproject/rollup-plugin-closure-compiler';

export default {
  input: 'main.js',
  output: {
    dir: 'public/module',
    format: 'es',
  },
  experimentalCodeSplitting: true,
  plugins: [
    compiler(),
  ],
}

Automatic Closure Configuration

This plugin will modify the enable the assume_function_wrapper output option for Closure Compiler when es format is specifed to Rollup. Note: This is overrideable via passed flags and options.

// rollup.config.js
import compiler from '@ampproject/rollup-plugin-closure-compiler';

export default {
  input: 'main.js',
  output: {
    file: 'bundle.js',
    format: 'es',
  },
  plugins: [
    compiler(),
  ],
}

If your Rollup configuration outputs an IIFE format bundle with a specified name, this plugin will add an extern to ensure the name does not get mangled. Note: This is overrideable via passed flags and options.

// rollup.config.js
import compiler from '@ampproject/rollup-plugin-closure-compiler';

export default {
  input: 'main.js',
  output: {
    file: 'bundle.js',
    format: 'iife',
    name: 'MyAwesomeThing'
  },
  plugins: [
    compiler(),
  ],
}

Additional Mangle Protection

If your source uses reserved words for identifiers or declarations, you can supply the list of words you would like to ensure are mangled before compilation, and renewed if they are used in an import or export statement.

// rollup.config.js
import compiler from '@ampproject/rollup-plugin-closure-compiler';

export default {
  input: 'main.js',
  output: {
    file: 'bundle.js',
    format: 'es',
  },
  plugins: [
    compiler({}, {
      mangleReservedWords: ['Plugin', 'Storage'],
    }),
  ],
}

Security disclosures

The AMP Project accepts responsible security disclosures through the Google Application Security program.

Code of conduct

The AMP Project strives for a positive and growing project community that provides a safe environment for everyone. All members, committers and volunteers in the community are required to act according to the code of conduct.

License

rollup-plugin-closure-compiler is licensed under the Apache License, Version 2.0.