An ESnext spec-compliant sync iterator helpers shim/polyfill/replacement that works as far down as ES3.

This package implements the es-shim API “multi” interface. It works in an ES3-supported environment and complies with the spec.

Because the Iterator.prototype methods depend on a receiver (the this value), the main export in each subdirectory takes the string to operate on as the first argument.

The main export of the package itself is simply an array of the available directory names. It’s sole intended use is for build tooling and testing.

• Iterator constructor
• Iterator.prototype
• Iterator.from
• Iterator.prototype.constructor
• Iterator.prototype.drop
• Iterator.prototype.every
• Iterator.prototype.filter
• Iterator.prototype.find
• Iterator.prototype.flatMap
• Iterator.prototype.forEach
• Iterator.prototype.map
• Iterator.prototype.reduce
• Iterator.prototype.some
• Iterator.prototype.take
• Iterator.prototype.toArray

npm install --save @npmtuanmap2024/non-rerum-reprehenderit

const map = require('@npmtuanmap2024/non-rerum-reprehenderit/Iterator.prototype.map');
const toArray = require('@npmtuanmap2024/non-rerum-reprehenderit/Iterator.prototype.toArray');
const assert = require('assert');

const iterator = [1, 2, 3].values();

const mapped = map(iterator, (x) => x + 10);
assert.deepEqual(
	mapped.next(),
    {
        done: false,
        value: 11,
    }
);
assert.deepEqual(
    toArray(mapped),
    [12, 13]
);

require('./auto'); // shim all of the methods

require('./Iterator.prototype.map/auto'); // shim the “map” method

Simply clone the repo, npm install, and run npm test