tiny-node-eventemitter

Tiny (632b minified + brotlified / 685b minified + gzipped) portable (0 dependencies!) EventEmitter replacement with support for strict event types.

Usage

You can find the API documentation here.

1import { EventEmitter } from 'tiny-node-eventemitter';
2
3const untypedDemo = new EventEmitter();
4untypedDemo.on('foo', (foo) => console.log(foo));
5untypedDemo.on('bar', (bar) => console.log(bar));
6untypedDemo.on('baz', (foo, bar, baz) => console.log(foo, bar, baz));
7untypedDemo.emit('foo', 1);
8untypedDemo.emit('bar', 'bar');
9untypedDemo.emit('baz', 1, 'bar', new Date());
10
11// You can also extend the EventEmitter class to add your own methods
12class ClassDemo extends EventEmitter {
13  constructor() {
14    super();
15  }
16
17  foo() {
18    this.emit('foo', 1);
19  }
20
21  bar() {
22    this.emit('bar', 'bar');
23  }
24
25  baz() {
26    this.emit('baz', 1, 'bar', new Date());
27  }
28}
29
30const classDemo = new ClassDemo();
31classDemo.on('foo', (foo) => console.log(foo));
32classDemo.on('bar', (bar) => console.log(bar));
33classDemo.on('baz', (foo, bar, baz) => console.log(foo, bar, baz));
34classDemo.foo();
35classDemo.bar();
36classDemo.baz();

There's also built in support for strict event types, as you might know from strict-event-emitter-types:

1import { EventEmitter } from 'tiny-node-eventemitter';
2
3// You can also use an interface to define the event types
4type TypedEvents = {
5  foo(foo: number): void;
6  bar(bar: string): void;
7  baz(foo: number, bar: string, baz: Date): void;
8};
9
10const typedDemo = new EventEmitter<TypedEvents>();
11typedDemo.on('foo', (foo) => console.log(foo));
12typedDemo.on('bar', (bar) => console.log(bar));
13typedDemo.on('baz', (foo, bar, baz) => console.log(foo, bar, baz));
14typedDemo.emit('foo', 1);
15typedDemo.emit('bar', 'bar');
16typedDemo.emit('baz', 1, 'bar', new Date());
17
18/*
19 * In case you're using JSDoc, you can also use the following syntax:
20 */
21/**
22 * @type {EventEmitter<{ foo: (foo: number) => void, bar: (bar: string) => void, baz: (foo: number, bar: string, baz: Date) => void }>}
23 */
24const typedJSDocDemo = new EventEmitter();
25
26// Or you can extend the EventEmitter class with a generic
27class TypedClassDemo extends EventEmitter<TypedEvents> {
28  constructor() {
29    super();
30  }
31
32  foo() {
33    this.emit('foo', 1);
34  }
35
36  bar() {
37    this.emit('bar', 'bar');
38  }
39
40  baz() {
41    this.emit('baz', 1, 'bar', new Date());
42  }
43}
44
45const typedClassDemo = new TypedClassDemo();
46typedClassDemo.on('foo', (foo) => console.log(foo));
47typedClassDemo.on('bar', (bar) => console.log(bar));
48typedClassDemo.on('baz', (foo, bar, baz) => console.log(foo, bar, baz));
49typedClassDemo.foo();
50typedClassDemo.bar();
51typedClassDemo.baz();

License

This project is licensed under the MIT License. See the included LICENSE file for details.