core/packages/shared/src/looseEqual.ts

import { isArray, isDate, isObject } from './'

function looseCompareArrays(a: any[], b: any[]) {
  if (a.length !== b.length) return false
  let equal = true
  for (let i = 0; equal && i < a.length; i++) {
    equal = looseEqual(a[i], b[i])
  }
  return equal
}

export function looseEqual(a: any, b: any): boolean {
  if (a === b) return true
  let aValidType = isDate(a)
  let bValidType = isDate(b)
  if (aValidType || bValidType) {
    return aValidType && bValidType ? a.getTime() === b.getTime() : false
  }
  aValidType = isArray(a)
  bValidType = isArray(b)
  if (aValidType || bValidType) {
    return aValidType && bValidType ? looseCompareArrays(a, b) : false
  }
  aValidType = isObject(a)
  bValidType = isObject(b)
  if (aValidType || bValidType) {
    /* istanbul ignore if: this if will probably never be called */
    if (!aValidType || !bValidType) {
      return false
    }
    const aKeysCount = Object.keys(a).length
    const bKeysCount = Object.keys(b).length
    if (aKeysCount !== bKeysCount) {
      return false
    }
    for (const key in a) {
      const aHasKey = a.hasOwnProperty(key)
      const bHasKey = b.hasOwnProperty(key)
      if (
        (aHasKey && !bHasKey) ||
        (!aHasKey && bHasKey) ||
        !looseEqual(a[key], b[key])
      ) {
        return false
      }
    }
  }
  return String(a) === String(b)
}

export function looseIndexOf(arr: any[], val: any): number {
  return arr.findIndex(item => looseEqual(item, val))
}