bare-events

library2.8.2jsnpmunverified

Bare Events is a lightweight and minimal event emitter library for JavaScript, designed for both Node.js and browser environments. It provides a simple API for event-driven programming, allowing developers to subscribe to and emit custom events efficiently. The package is actively maintained, with version 2.8.2 being the latest stable release as of late 2025/early 2026, and new versions released as needed. As part of the Holepunch ecosystem, it emphasizes a 'bare-bones' approach, contrasting with more feature-rich alternatives by focusing solely on core event emitting functionality. It ships with built-in TypeScript type declarations, making it well-suited for modern JavaScript and TypeScript projects that prioritize minimal overhead and explicit control over event handling.

communication

npm install bare-events

github ↗package ↗

INSTALL

IMPORT

SIG · BARE-EVENTS

bare-events

communicationjavascriptv2.8.2

Install

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Import

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Disk

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Pass rate

0/ 6

Env Coverage0 / 6

glibc

18–22

musl

18–22

Install & Compatibility

Where this runs

tested against v? · npm install

Install × environment matrix

Each cell = how many times install + import succeeded across repeated harness runs. Partial = flaky.
glibc = Debian/Ubuntu slim · musl = Alpine Linux

musl

node 18–226 runs

build_error

glibc

node 18–226 runs

build_error

Code

Verified usage

Verified import paths — ran on the pinned version, not inferred.

EventEmitter

✓ import { EventEmitter } from 'bare-events'

✗ import EventEmitter from 'bare-events'

Bare Events uses named exports for its primary `EventEmitter` class, even in ESM contexts. Direct default imports will result in `undefined` or an error.

EventEmitter

✓ const EventEmitter = require('bare-events')

This is the standard CommonJS import pattern, as shown in the package's documentation.

EventEmitter (type)

✓ import type { EventEmitter } from 'bare-events'

When using TypeScript, prefer `import type` for type-only imports to ensure they are stripped from the compiled JavaScript, preventing runtime overhead and potential issues.

This quickstart demonstrates how to create a typed event emitter, subscribe to events with `on` and `once`, emit events with `emit`, and properly clean up listeners using `off`.

import { EventEmitter } from 'bare-events'; interface MyEvents { 'data': (payload: string) => void; 'ready': () => void; 'error': (err: Error) => void; } // Create a new EventEmitter instance, typed for better safety const myEmitter = new EventEmitter<MyEvents>(); // Subscribe to the 'data' event myEmitter.on('data', (payload: string) => { console.log(`Received data: ${payload}`); }); // Subscribe to the 'ready' event, only once myEmitter.once('ready', () => { console.log('Emitter is ready!'); }); // Emit events myEmitter.emit('data', 'Hello, world!'); myEmitter.emit('ready'); myEmitter.emit('data', 'Another piece of data!'); // Demonstrate removing a listener const errorHandler = (err: Error) => console.error('Caught error:', err.message); myEmitter.on('error', errorHandler); myEmitter.emit('error', new Error('Something went wrong!')); myEmitter.off('error', errorHandler); // Remove the specific listener myEmitter.emit('error', new Error('This error will crash the process if no other listener is present.')); // No listener, will crash in Node.js

Debug

Known issues

gotchaFailing to remove event listeners, especially for long-lived emitters or frequently created components, can lead to memory leaks. This is a common pitfall with all event emitter implementations.

fix

Always pair `on` or `once` with a corresponding `off` call when the listener is no longer needed. Consider using `AbortController` (via `bare-abort-controller`) to manage listener lifecycles, or ensure components clean up their listeners on unmount/destroy.

affects: >=1.0.0

breakingIn Node.js, if an `error` event is emitted and no listeners are attached to it, the process will crash. This default behavior can be unexpected for new users.

fix

Always add a listener for the `error` event on any `EventEmitter` instance that might emit errors. For example: `myEmitter.on('error', (err) => console.error('Caught:', err));`

affects: >=1.0.0

gotchaThe `this` context within event listener functions can be inconsistent depending on how the function is defined and called. Traditional `function` declarations will have `this` bound to the `EventEmitter` instance, but arrow functions retain the `this` from their lexical scope.

fix

Use arrow functions (`(payload) => { /* ... */ }`) if you want `this` to refer to the surrounding lexical context. If you explicitly need `this` to be the `EventEmitter` instance, use a traditional `function (payload) { /* ... */ }` declaration or manually bind the function (e.g., `listener.bind(myEmitter)`).

affects: >=1.0.0

gotchaWhen migrating from CommonJS `require()` to ES Modules `import`, ensure you use named imports (`import { EventEmitter } from 'bare-events'`) rather than default imports, as `bare-events` does not provide a default export for its main class.

fix

Update `import EventEmitter from 'bare-events'` to `import { EventEmitter } from 'bare-events'` in ES Module files. Ensure your build configuration correctly handles module resolution for both CJS and ESM if you have a mixed codebase.

affects: >=1.0.0

Errors

Common errors & fixes

TypeError: EventEmitter is not a constructor

Attempting to instantiate `EventEmitter` when it was incorrectly imported as a default export in an ES Module context or when destructuring a CommonJS `require` call incorrectly.

fix

For ES Modules: `import { EventEmitter } from 'bare-events';`. For CommonJS: `const EventEmitter = require('bare-events');` (without destructuring if the top-level export is the constructor).

Unhandled 'error' event. ([Error object details])

An `error` event was emitted by an `EventEmitter` instance, but no listener was registered to handle it. In Node.js, this typically leads to a process crash.

fix

Always register an error handler for any `EventEmitter` that might emit errors: `myEmitter.on('error', (err) => { console.error('Caught an error:', err); });`

ReferenceError: require is not defined in ES module scope

Attempting to use `require()` in an ES Module (ESM) file (e.g., a `.mjs` file or a `.js` file in a package with `"type": "module"` in `package.json`).

fix

Switch to ES Module `import` syntax: `import { EventEmitter } from 'bare-events';`

Upgrade

Version history

2.8.2latest on npm

Audit

Dependencies

bare-abort-controllerrequiredPeer dependency, likely used for advanced event cancellation mechanisms, providing a standard way to signal cancellation to event listeners or asynchronous operations.

Agent activity

44 hits · last 30 days

node

OpenAI (training)

Resources

githubhttps://github.com/holepunchto/bare-events ↗

packagehttps://www.npmjs.com/package/bare-events ↗