ice.fo.utils/Array.js

import _groupBy from 'lodash/groupBy'
import _get from 'lodash/get'
import _isEqual from 'lodash/isEqual'
import _isFunction from 'lodash/isFunction'

/**
 * Group a list of objects by [key] name. The [key] also supports properties path access e.g. 'user.profile.name'
 * 
 * @example
 * groupByKey([{name: 'nikochin', age: 10}, {name: 'nikochin', age: 30}, {name: 'edward', age: 10}], 'name', true); // returns [ [{name: 'nikochin', age: 10}, {name: 'nikochin', age: 30}], [{name: 'edward', age: 10}] ]
 * 
 * @param {any[]} list 
 * @param {string|string[]} key 
 * @param {boolean} keepOrder 
 * @returns An list of objects list grouped by key
 */
export function groupByKey (list, key, keepOrder = false) {
  if (!keepOrder) {
    return Object.values(_groupBy(list, i => _get(i, key)))
  }

  const result = []
  const firstItem = _get(list, '0')
  const isFuncKey = _isFunction(key)

  let previousValue = isFuncKey ? key(firstItem) : _get(firstItem, key)
  let previousList = []

  list.forEach((item) => {
    const value = isFuncKey ? key(item) : _get(item, key)

    if (_isEqual(value, previousValue)) {
      previousList.push(item)
    } else {
      result.push(previousList)
      previousList = [item]
      previousValue = value
    }
  })

  if (previousList.length) {
    result.push(previousList)
  }

  return result
}

/**
 * Merge 2 array and remove previous duplicate
 * 
 * @param {any[]} a 
 * @param {any[]} b 
 * @param {(any) => string} indicator 
 * @returns 
 */
export function mergeUnique (a, b, indicator = i => i.id) {
  const result = []
  const dict = {}

  a.forEach((i, index) => {
    result.push(i)
    dict[indicator(i)] = index
  })

  b.forEach((i) => {
    const foundIndex = dict[indicator(i)]
    if (foundIndex != null) {
      result.splice(foundIndex, 1, i)
    } else {
      result.push(i)
    }
  })

  return result
}

/**
 * Creates an array of elements split into groups with length size. If array can't be split evenly, the final chunk will be the remaining elements.
 *
 * @example
 * splitIntoChunks([1,2,3,4], 2); // returns [ [1,2], [3,4] ]
 * splitIntoChunks([1,2,3,4], 3); // returns [ [1,2,3], [4] ]
 * splitIntoChunks([1,2,3,4], 5); // returns [ [1,2,3,4] ]
 *
 * @param array
 * @param length
 * @returns {[]}
 */
export function splitIntoChunks (array, length) {
  if (array.length < length) {
    return [array]
  }

  const result = []
  const chunkCount = Math.ceil(array.length / length)

  for (let i = 0; i < chunkCount; i++) {
    result.push(array.slice(i * length, i * length + length))
  }

  return result
}