Package Exports

tiny-typed-emitter

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Readme

tiny-typed-emitter

Have your events and their listeners type-checked with minimal overhead.

Install

Simply add the dependency using npm:

$ npm i tiny-typed-emitter

or using yarn:

$ yarn add tiny-typed-emitter

Usage

import tiny-typed-emitter library:

import { TypedEmitter } from 'tiny-typed-emitter';

define events and their listener signatures (note: quotes around event names are not mandatory):

interface MyClassEvents {
  'added': (el: string, wasNew: boolean) => void;
  'deleted': (deletedCount: number) => void;
}

on this step depending on your use case, you can:

define your custom class extending EventEmitter:

class MyClass extends TypedEmitter<MyClassEvents>() {
  constructor() {
    super();
  }
}

define typed class:

const TEvenetEmitter = TypedEmitter<MyClassEvents>();
// and then use it to create event emitters:
const emitter = new TEventEmitter();

directly create new event emitter instance (though this syntax isn't exactly pretty...):
```
const emitter = new (TypedEmitter<MyClassEvent>())();
```

Generic events interface

To use with generic events interface:

interface MyClassEvents<T> {
  'added': (el: T, wasNew: boolean) => void;
}

class MyClass<T>
  extends TypedEmitter<MyClassEvents<any>>()
  implements TypedEmitter<MyClassEvents<T>>
{

}

Minimal Overhead

Library adds basically no overhead by exposing a function which essentially returns EventEmitter type casted class. This is essentially what typescript generates and what will be included in your application:

var events_1 = require("events");
function TypedEmitter() {
    return events_1.EventEmitter;
}
exports.TypedEmitter = TypedEmitter;