happypack-2-block.js

const { group } = require('@webpack-blocks/core')
const HappyPack = require('happypack');

module.exports = happypack

function happypack (blocks) {
	return group(blocks.map(happyfyBlock))
}

/**
 * Returns a new block wrapping `block` that creates a happypack loader config.
 */
function happyfyBlock (block) {
	const happyBlock = happyfySetter(block)
	const pre = toArray(block.pre)
	const post = toArray(block.post).map(postHook => happyfySetter(postHook))

	return Object.assign(happyBlock, { pre, post })
}

/**
 * Takes a block or a post hook and returns a wrapping function that creates a happypack loader config.
 */
function happyfySetter (setter) {
	return (context, config) => happyfyConfig(setter(context, config), context)
}

/**
 * Transforms a non-happypack loader config into a happypack loader config.
 */
function happyfyConfig (configSnippet) {
	if (configSnippet.module && configSnippet.module.loaders) {
		const plugins = [];
		const loaders = configSnippet.module.loaders.map((loader, id) => {
			const happypackplugin = new HappyPack({
				id: `loader${id}`,
				loaders: loader.loaders,
			});
			plugins.push(happypackplugin);
			return {
				test: loader.test,
				loader: `happypack/loader?id=loader${id}`,
				exclude: loader.exclude || [],
			}
		});

		return {
			module: {
				loaders,
			},
			plugins,
		}
	}
	return {};
}

/**
 * Takes an array, a function or something falsy and returns the array, the
 * function wrapped in an array or an empty array, respectively.
 */
function toArray (value) {
	if (value) {
		return Array.isArray(value) ? value : [ value ]
	} else {
		return []
	}
}