The core-js-pure package provides a version of the core-js standard library that does not pollute the global namespace. Instead of modifying built-in prototypes (like Array.prototype), you import specific features as standalone modules and use them as functions. This is ideal for library authors who want to use modern ECMAScript features without affecting the environment of the applications consuming their library.
To use it, import the required features from core-js-pure/actual/... and call them directly with your data as the first argument.
import Promise from 'core-js-pure/actual/promise';
import Set from 'core-js-pure/actual/set';
import Iterator from 'core-js-pure/actual/iterator';
import from from 'core-js-pure/actual/array/from';
import flatMap from 'core-js-pure/actual/array/flat-map';
import structuredClone from 'core-js-pure/actual/structured-clone';
// Usage examples:
Promise.try(() => 42).then(it => console.log(it)); // => 42
from(new Set([1, 2, 3]).union(new Set([3, 4, 5]))); // => [1, 2, 3, 4, 5]
flatMap([1, 2], it => [it, it]); // => [1, 1, 2, 2]
Iterator.concat([1, 2], function * (i) { while (true) yield i++; }(3))
.drop(1).take(5)
.filter(it => it % 2)
.map(it => it ** 2)
.toArray(); // => [9, 25]
structuredClone(new Set([1, 2, 3])); // => new Set([1, 2, 3])
