ts-decorated-events v1.0.6

ts-decorated-events

A typed version of Node.js EventEmitter with TypeScript decorators.

import { EventEmitter, Events, EventDecorator, on, once } from "ts-decorated-events";

// redefine on and once to the correct type
const testOn: EventDecorator<TestEvents> = on;
const testOnce: EventDecorator<TestEvents> = once;

// define the events
interface TestEvents extends Events {
  event1: [string, number];
  event2: [number, string];
}

// decorators can be used on methods and static methods
class Test extends EventEmitter<TestEvents> {

  @testOn("event1")
  public onEvent1(a: string, b: number) {
    // -- do stuff
  }

  @testOnce("event2")
  public static onEvent2(emitter: Test, a: number, b: string) {
    // -- do static stuff once
  }

}

You can define the events as a type instead of an interface to be stricter.\ Defining the types as an interface allows calling unknown events.

type TestEvents = {
  event1: [string, number];
  event2: [number, string];
}

You can also use this notation to name the tuple members:

interface TestEvents extends Events {
  event1: Parameters<(a: string, b: number) => 0>;
  event2: Parameters<(a: number, b: string) => 0>;
}

Or using TypeScript 4:

interface TestEvents extends Events {
  event1: [a: string, b: number];
  event2: [a: number, b: string];
}