es-abstract

What is es-abstract?

The es-abstract npm package provides utility functions for ECMAScript language abstract operations. These operations are the fundamental building blocks of the ECMAScript specification, which JavaScript and other related languages are based on. The package includes methods for type conversion, manipulation of objects, and working with language semantics as defined in various ECMAScript editions.

What are es-abstract's main functionalities?

Type Conversion

Converts a value to a number as per ECMAScript abstract operation ToNumber.

const ES = require('es-abstract');
const value = '123';
const number = ES.ToNumber(value);

Object Manipulation

Gets an array of the own enumerable property names of an object.

const ES = require('es-abstract');
const obj = { a: 1 };
const keys = ES.EnumerableOwnNames(obj);

Working with Language Semantics

Calls a given function with a specific this value and arguments list.

const ES = require('es-abstract');
const result = ES.Call(Function.prototype.toString, () => {});

Other packages similar to es-abstract

lodash

Lodash is a popular utility library that offers a wide range of functions for manipulating objects, arrays, numbers, strings, etc. It is more focused on practical application development rather than strictly adhering to ECMAScript abstract operations.

core-js

Core-js is a modular standard library for JavaScript, which includes polyfills for ECMAScript features. It provides functionality similar to es-abstract in terms of implementing ECMAScript standards, but it also includes polyfills for newer language features.

README

es-abstract

ECMAScript spec abstract operations.

Every operation is available by edition/year and by name - for example, es-abstract/2020/Call gives you the Call operation from ES2020, es-abstract/5/Type gives you the Type operation from ES5.

All abstract operations are also available under an es5/es2015/es2016/es2017/es2018/es2019/es2020/es2021 entry point, and as a property on the main export, but using deep imports is highly encouraged for bundle size and performance reasons. Non-deep entry points will be removed in the next semver-major release.

Example

var ES = require('es-abstract');
var assert = require('assert');

assert(ES.isCallable(function () {}));
assert(!ES.isCallable(/a/g));

Tests

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

Security

Please email @ljharb or see https://tidelift.com/security if you have a potential security vulnerability to report.