@webpack-blocks/core/lib/blockUtils.js

Functional approach to compose your webpack config.

const _ = require('lodash')
const webpackMerge = require('webpack-merge')

module.exports = {
  merge,
  addLoader,
  addPlugin
}

function merge(configSnippet) {
  return prevConfig => webpackMerge.smart(prevConfig, configSnippet)
}

function addLoader(loaderDef) {
  const cleanedLoaderDef = _.omitBy(loaderDef, _.isUndefined)
  return prevConfig =>
    webpackMerge.smart(prevConfig, {
      module: {
        rules: [cleanedLoaderDef]
      }
    })
}

function addPlugin(plugin) {
  return prevConfig =>
    Object.assign({}, prevConfig, { plugins: prevConfig.plugins.concat([plugin]) })
}