fliphub-monorepo/modules-sub/flip-webpack-chain/src/Rule.js

the builder of builders

const ChainedMap = require('./ChainedMap')
const ChainedSet = require('./ChainedSet')
const Use = require('./Use')

module.exports = class extends ChainedMap {
  constructor(parent) {
    super(parent)
    this.uses = new ChainedMap(this)
    this.include = new ChainedSet(this)
    this.exclude = new ChainedSet(this)
    this.extend(['parser', 'test', 'enforce'])
  }

  use(name) {
    if (!this.uses.has(name)) {
      this.uses.set(name, new Use(this))
    }

    return this.uses.get(name)
  }

  pre() {
    return this.enforce('pre')
  }

  post() {
    return this.enforce('post')
  }

  toConfig() {
    return this.clean(Object.assign(this.entries() || {}, {
      include: this.include.values(),
      exclude: this.exclude.values(),
      use: this.uses.values().map(use => use.toConfig())
    }))
  }

  merge(obj) {
    Object
      .keys(obj)
      .forEach(key => {
        const value = obj[key]

        switch (key) {
          case 'include':
          case 'exclude': {
            return this[key].merge(value)
          }

          case 'use': {
            return Object
              .keys(value)
              .forEach(name => this.use(name).merge(value[name]))
          }

          case 'test': {
            return this.test(value instanceof RegExp ? value : new RegExp(value))
          }

          default: {
            this.set(key, value)
          }
        }
      })

    return this
  }
}