findIndex.js

  1. 'use strict';
  3. const { Each } = require('./each');
  4. const { setShorthand } = require('./internal/collection');
  6. class FindIndex extends Each {
  7.   constructor(collection, iterator) {
  8.     super(collection, iterator, set);
  9.     this._result = -1;
  10.   }
  12.   _callResolve(value, index) {
  13.     if (value) {
  14.       this._size = 0;
  15.       this._promise._resolve(index);
  16.     } else if (--this._rest === 0) {
  17.       this._promise._resolve(-1);
  18.     }
  19.   }
  20. }
  22. module.exports = { findIndex, FindIndex };
  24. function set(collection) {
  25.   setShorthand.call(this, collection);
  26.   if (this._keys !== undefined) {
  27.     this._rest = 0;
  28.   }
  29.   return this;
  30. }
  32. /**
  33.  * `Aigle.findIndex` is like `Aigle.find`, it will return the index of the first element which the iterator returns truthy.
  34.  * @param {Array} collection
  35.  * @param {Function|Array|Object|string} iterator
  36.  * @return {Aigle} Returns an Aigle instance
  37.  * @example
  38.  * const order = [];
  39.  * const collection = [1, 4, 2];
  40.  * const iterator = num => {
  41.  *   return Aigle.delay(num * 10)
  42.  *     .then(() => {
  43.  *       order.push(num);
  44.  *       return num % 2 === 0;
  45.  *     });
  46.  * };
  47.  * Aigle.findIndex(collection, iterator)
  48.  *   .then(index => {
  49.  *     console.log(index); // 2
  50.  *     console.log(order); // [1, 2]
  51.  *   });
  52.  *
  53.  * @example
  54.  * const order = [];
  55.  * const collection = [1, 4, 2];
  56.  * const iterator = num => {
  57.  *   return Aigle.delay(num * 10)
  58.  *     .then(() => {
  59.  *       order.push(num);
  60.  *       return false;
  61.  *     });
  62.  * };
  63.  * Aigle.findIndex(collection, iterator)
  64.  *   .then(index => {
  65.  *     console.log(index); // -1
  66.  *     console.log(order); // [1, 2, 4]
  67.  *   });
  68.  *
  69.  * @example
  70.  * const collection = [{
  71.  *   name: 'bargey', active: false
  72.  * }, {
  73.  *   name: 'fread', active: true
  74.  * }];
  75.  * Aigle.findIndex(collection, 'active')
  76.  *   .then(index => {
  77.  *     console.log(index); // 1
  78.  *   });
  79.  *
  80.  * @example
  81.  * const collection = [{
  82.  *   name: 'bargey', active: false
  83.  * }, {
  84.  *   name: 'fread', active: true
  85.  * }];
  86.  * Aigle.findIndex(collection, ['name', 'fread'])
  87.  *   .then(index => {
  88.  *     console.log(index); // true
  89.  *   });
  90.  *
  91.  * @example
  92.  * const collection = [{
  93.  *   name: 'bargey', active: false
  94.  * }, {
  95.  *   name: 'fread', active: true
  96.  * }];
  97.  * Aigle.find(collection, { name: 'fread', active: true })
  98.  *   .then(index => {
  99.  *     console.log(index); // 1
  100.  *   });
  101.  */
  102. function findIndex(collection, iterator) {
  103.   return new FindIndex(collection, iterator)._execute();
  104. }