'use strict'; const pLimit = require('p-limit');
class EndError extends Error {
constructor(value) { super(); this.value = value; }
}
// The input can also be a promise, so we `Promise.resolve()` it const testElement = (el, tester) => Promise.resolve(el).then(tester);
// The input can also be a promise, so we `Promise.all()` them both const finder = el => Promise.all(el).then(val => val === true && Promise.reject(new EndError(val)));
module.exports = (iterable, tester, opts) => {
opts = Object.assign({ concurrency: Infinity, preserveOrder: true }, opts); const limit = pLimit(opts.concurrency); // Start all the promises concurrently with optional limit const items = [...iterable].map(el => [el, limit(testElement, el, tester)]); // Check the promises either serially or concurrently const checkLimit = pLimit(opts.preserveOrder ? 1 : Infinity); return Promise.all(items.map(el => checkLimit(finder, el))) .then(() => {}) .catch(err => err instanceof EndError ? err.value : Promise.reject(err));
};