auto-bind-js

Automatically bind class methods to their instance. Zero dependencies.

A modern, feature-rich alternative to auto-bind with extra capabilities: lazy binding, regex pattern matching, decorators, Symbol-keyed methods, and full TypeScript support.

Install

npm install auto-bind-js

Usage

Basic

import autoBind from 'auto-bind-js';

class Unicorn {
  constructor(name) {
    this.name = name;
    autoBind(this);
  }

  message() {
    return `${this.name} is awesome!`;
  }
}

const unicorn = new Unicorn('Rainbow');
const { message } = unicorn;
message(); //=> 'Rainbow is awesome!'

CommonJS

const autoBind = require('auto-bind-js');

module.exports = class Controller {
  constructor() {
    autoBind(this);
  }

  index(req, res) {
    // `this` is always bound to the instance
    res.json(this.getData());
  }

  getData() {
    return { status: 'ok' };
  }
};

Bind specific methods (shorthand)

autoBind(this, 'handleClick', 'handleSubmit');

Options

// Only bind these methods
autoBind(this, { include: ['handleClick', 'handleSubmit'] });

// Bind all except these
autoBind(this, { exclude: ['render', 'toString'] });

// Bind only methods matching a pattern
autoBind(this, { pattern: /^handle/ });

// Lazy binding — binds on first access (better perf for large classes)
autoBind(this, { lazy: true });

React

Excludes all React lifecycle methods automatically:

import autoBindReact from 'auto-bind-js/react';

class MyComponent extends React.Component {
  constructor(props) {
    super(props);
    autoBindReact(this);
  }

  handleClick() {
    // `this` is always the component instance
  }

  render() {
    return <button onClick={this.handleClick}>Click</button>;
  }
}

Decorators

import { boundClass, bound } from 'auto-bind-js/decorator';

// Class decorator — binds ALL methods
@boundClass
class Foo {
  constructor() {
    this.name = 'foo';
  }

  handleClick() {
    return this.name; // always bound
  }
}

// Method decorator — bind individual methods
class Bar {
  constructor() {
    this.name = 'bar';
  }

  @bound
  handleClick() {
    return this.name; // always bound
  }
}

API

autoBind(self, options?)

Bind methods of self to the instance. Returns self.

Options

| Option | Type | Description | | --------- | -------------------- | ---------------------------------------------- | | include | (string\|symbol)[] | Only bind these methods | | exclude | (string\|symbol)[] | Skip these methods | | pattern | RegExp | Only bind methods whose names match this regex | | lazy | boolean | Bind on first access instead of immediately |

autoBindReact(self, options?)

Same as autoBind but automatically excludes React lifecycle methods (render, componentDidMount, shouldComponentUpdate, etc.)

boundClass(target)

Class decorator. Auto-binds all methods when the class is instantiated.

bound(target, key, descriptor)

Method decorator. Lazily binds the decorated method to the instance on first access.

Features

• ✅ Zero dependencies
• ✅ Binds inherited methods
• ✅ Supports Symbol-keyed methods
• ✅ Include/exclude filters
• ✅ Regex pattern matching
• ✅ Lazy binding mode
• ✅ React lifecycle awareness
• ✅ Class & method decorators
• ✅ Full TypeScript declarations
• ✅ ESM + CommonJS dual package
• ✅ Lightweight (~2KB)

License

MIT