happypack-block.js

const HappyPack = require('happypack')


module.exports = happyPack

function happyPack (blocks = [], options = {}) {

	const happyThreadPool = HappyPack.ThreadPool({ size: options.size || 5 })

	return (context, webpackConfig) => {

		const loaders = [];
		const plugins = blocks.map((loader, id) => {
			const block = loader(context, webpackConfig) // invoke block to get info
			const cacheKey = `cache-file-${id}` // generate cache key

			loaders.push({
				test: block.test,
				loaders: [`happypack/loader?id=${cacheKey}`],
			})

			return new HappyPack({
				loaders: block.module.loaders,
				threadPool: happyThreadPool,
			})
		})

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