Returns a Promise which resolves with a new Array, containing only values which passed the test.

promiseFilter.js

/**
* promiseFilter - Returns a Promise which resolves with a new Array, containing only values which passed the test.
* @param {Array} array    An Array from which to filter values into a new Array.
* @param {callback} test  A callback function which must return a Promise, which must resolve with a Boolean.
	* @callback test
		* @param {any} value     The current value from `array`.
		* @param {Number} index  The current index being used to access `array`.
		* @param {Array} array   The Array being iterated through, `array`.
* @returns {Promise}          A Promise which resolves with a new Array containing values which passed the test.
*/
function promiseFilter(array, test) {
	return Promise.all(
		array.map((val, acc) => test(val, acc, array))
	).then(
		results => resolve(array.filter((val, acc) => results[acc]))
	);
}
if (module !== undefined) module.exports = promiseFilter;
/**
* How To Use
* Below is an example dataset, test, and usage.
* The test returns `true` if the number is divisible by 2, or false if otherwise.
* -----------
const numberArray = [0,1,2,3,4,5,6,7,8,9];
const test = (value, index, array) => value % 2 === 0;
promiseFilter(numberArray, test).then(console.log);
* ------------
* Logs the following: [0,2,4,6,8]
*/