Interface TypedEventEmitter<Events>

Type-safe event emitter.

Use it like this:

type MyEvents = {
  error: (error: Error) => void;
  message: (from: string, content: string) => void;
}

const myEmitter = new EventEmitter() as TypedEmitter<MyEvents>;

myEmitter.emit("error", "x")  // <- Will catch this type error;

interface TypedEventEmitter {
    addListener<E>(event, listener): TypedEventEmitter<Events>;
    emit<E>(event, ...args): boolean;
    eventNames(): (string | symbol | keyof Events)[];
    getMaxListeners(): number;
    listenerCount<E>(event): number;
    listeners<E>(event): Events[E][];
    off<E>(event, listener): TypedEventEmitter<Events>;
    on<E>(event, listener): TypedEventEmitter<Events>;
    once<E>(event, listener): TypedEventEmitter<Events>;
    prependListener<E>(event, listener): TypedEventEmitter<Events>;
    prependOnceListener<E>(event, listener): TypedEventEmitter<Events>;
    rawListeners<E>(event): Events[E][];
    removeAllListeners<E>(event?): TypedEventEmitter<Events>;
    removeListener<E>(event, listener): TypedEventEmitter<Events>;
    setMaxListeners(maxListeners): TypedEventEmitter<Events>;
}

Type Parameters

Events extends EventMap

Index

Methods

addListener emit eventNames getMaxListeners listenerCount listeners off on once prependListener prependOnceListener rawListeners removeAllListeners removeListener setMaxListeners

Methods

addListener

addListener<E>(event, listener): TypedEventEmitter<Events>
Type Parameters
- E extends string | number | symbol
Parameters
- event: E
- listener: Events[E]
Returns TypedEventEmitter<Events>

emit

emit<E>(event, ...args): boolean
Type Parameters
- E extends string | number | symbol
Parameters
- event: E
- Rest ...args: Parameters<Events[E]>
Returns boolean

eventNames

eventNames(): (string | symbol | keyof Events)[]
Returns (string | symbol | keyof Events)[]

getMaxListeners

getMaxListeners(): number
Returns number

listenerCount

listenerCount<E>(event): number
Type Parameters
- E extends string | number | symbol
Parameters
- event: E
Returns number

listeners

listeners<E>(event): Events[E][]
Type Parameters
- E extends string | number | symbol
Parameters
- event: E
Returns Events[E][]

off

off<E>(event, listener): TypedEventEmitter<Events>
Type Parameters
- E extends string | number | symbol
Parameters
- event: E
- listener: Events[E]
Returns TypedEventEmitter<Events>

on

on<E>(event, listener): TypedEventEmitter<Events>
Type Parameters
- E extends string | number | symbol
Parameters
- event: E
- listener: Events[E]
Returns TypedEventEmitter<Events>

once

once<E>(event, listener): TypedEventEmitter<Events>
Type Parameters
- E extends string | number | symbol
Parameters
- event: E
- listener: Events[E]
Returns TypedEventEmitter<Events>

prependListener

prependListener<E>(event, listener): TypedEventEmitter<Events>
Type Parameters
- E extends string | number | symbol
Parameters
- event: E
- listener: Events[E]
Returns TypedEventEmitter<Events>

prependOnceListener

prependOnceListener<E>(event, listener): TypedEventEmitter<Events>
Type Parameters
- E extends string | number | symbol
Parameters
- event: E
- listener: Events[E]
Returns TypedEventEmitter<Events>

rawListeners

rawListeners<E>(event): Events[E][]
Type Parameters
- E extends string | number | symbol
Parameters
- event: E
Returns Events[E][]

removeAllListeners

removeAllListeners<E>(event?): TypedEventEmitter<Events>
Type Parameters
- E extends string | number | symbol
Parameters
- Optional event: E
Returns TypedEventEmitter<Events>

removeListener

removeListener<E>(event, listener): TypedEventEmitter<Events>
Type Parameters
- E extends string | number | symbol
Parameters
- event: E
- listener: Events[E]
Returns TypedEventEmitter<Events>

setMaxListeners

setMaxListeners(maxListeners): TypedEventEmitter<Events>
Parameters
- maxListeners: number
Returns TypedEventEmitter<Events>