woocommerce/plugins/woocommerce-blocks/bin/add-split-chunk-dependencies.js

// The Dependency Extraction Webpack Plugin does not add split chunks as dependencies
// to the .asset.php files that list dependencies. In the past we manually enqueued
// those dependencies in PHP.
// For every generated .asset.php file in the whole bundle, this plugin prefixes the
// list of dependencies with the handles of split chunks that were generated in the build.

// e.g. if your bundle has a vendors script called foo-vendors then for every entry-point
// that has a .asset.php file generated by Dependency Extraction Webpack Plugin
// the plugin will edit that file to include foo-vendors as a listed dependency.

// This means for any split chunk you build you'll only need to register it in PHP, but all
// files that depend on it will automatically include it as a dependency.
class AddSplitChunkDependencies {
	apply( compiler ) {
		compiler.hooks.thisCompilation.tap(
			'AddStableChunksToAssets',
			( compilation ) => {
				compilation.hooks.processAssets.tap(
					{
						name: 'AddStableChunksToAssets',
						stage: compiler.webpack.Compilation
							.PROCESS_ASSETS_STAGE_ANALYSE,
					},
					() => {
						const { chunks } = compilation;

						const splitChunks = chunks.filter( ( chunk ) => {
							return chunk?.chunkReason?.includes( 'split' );
						} );

						// find files that have an asset.php file
						const chunksToAddSplitsTo = chunks.filter(
							( chunk ) => {
								return (
									! chunk?.chunkReason?.includes( 'split' ) &&
									chunk.files.find( ( file ) =>
										file.endsWith( 'asset.php' )
									)
								);
							}
						);

						for ( const chunk of chunksToAddSplitsTo ) {
							const assetFile = chunk.files.find( ( file ) =>
								file.endsWith( 'asset.php' )
							);

							const assetFileContent = compilation.assets[
								assetFile
							]
								.source()
								.toString();

							const extraDependencies = splitChunks
								.map( ( c ) => `'${ c.name }'` )
								.join( ', ' );

							const updatedFileContent = assetFileContent.replace(
								/('dependencies'\s*=>\s*array\s*\(\s*)([^)]*)\)/,
								`$1${ extraDependencies }, $2)`
							);

							compilation.assets[ assetFile ] = {
								source: () => updatedFileContent,
								size: () => updatedFileContent.length,
							};
						}
					}
				);
			}
		);
	}
}

module.exports = AddSplitChunkDependencies;