microlinkhq / metascraper / 5799694691

'use strict'

const {

  cloneDeep,

  concat,

  first,

  findIndex,

  forEach,

  chain,

  castArray,

  has,

  set

} = require('lodash')

const forEachRule = (collection, fn) => forEach(castArray(collection), fn)

const loadRules = rulesBundle =>

  chain(rulesBundle)

    .reduce((acc, { test, ...rules }) => {

      forEach(rules, (innerRules, propName) => {

        set(

          acc,

          propName,

          has(acc, propName)

            ? concat(acc[propName], innerRules)

            : concat(innerRules)

        )

        return acc

      })

      return acc

    }, {})

    .toPairs()

    .value()

const mergeRules = (rules, baseRules) =>

  chain(rules)

    .reduce((acc, { test, ...rules }) => {

      forEach(rules, (innerRules, propName) => {

        // find the rules associated with `propName`

        const index = findIndex(acc, item => first(item) === propName)

        // if `propName` has more rule, add the new rule from the end

        if (index !== -1) acc[index][1] = concat(innerRules, ...acc[index][1])

        // otherwise, create an array of rules

        else acc.push([propName, castArray(innerRules)])

      })

      return acc

    }, cloneDeep(baseRules))

    .value()

module.exports = { mergeRules, loadRules }