ChunksToHermesBytecode Plugin

This plugin is designed to convert JavaScript chunks into Hermes bytecode for production-level performance optimization. It also converts related source maps to be compatible with bytecode bundles.

INFO

This plugin will only transform assets that are emitted after the compilation. To ensure that asset is always emitted we disable the compareBeforeEmit option which is enabled by default in Webpack.

compareBeforeEmit option is used to skip emitting assets that are identical to the ones present in build directory, which might result in transformation being skipped when there is a untransformed bundle present in the build directory.

Usage

webpack.config.js
import * as Repack from '@callstack/repack';

new Repack.plugins.ChunksToHermesBytecodePlugin({
    enabled: mode === 'production' && !devServer,
    test: /\.(js)?bundle$/,
    exclude: /index.bundle$/,
}),
WARNING

If you enable Hermes in your project, your index.bundle file and it's source-map will be transformed by react-native. You should exclude it from the plugin to avoid processing it twice.

Configuration

enabled

  • Required
  • Type: boolean

Use this to enable or disable the plugin. You should only enable this plugin when building for production environment.

test

  • Required
  • Type: string[] | RegExp | RegExp[]

Matches all modules that match this resource, and will match against Resource (the absolute path without query and fragment).

include

  • Type: string[] | RegExp | RegExp[]

Matches all modules that match this condition against the absolute path of the resource (without query and fragment).

exclude

  • Type: string[] | RegExp | RegExp[]

Excludes all modules that match this condition and will match against the absolute path of the resource (without query and fragment).

hermesCLIPath

  • Type: string

Path to the Hermes command-line tool. If not specified, the plugin will try to find it automatically.

reactNativePath

  • Type: string

Use this to specify the path to the React Native package. If not specified, the plugin will try to find it automatically.

compareBeforeEmit

  • Type: boolean

Use this to force enable compareBeforeEmit Webpack's output option.