Tiny Event Emitter

event-emitter.ts

type Callback<T> = (value: T) => void

export class EventEmitter<T> {
  #on = new Set<Callback<T>>([])

  set on(cb: Callback<T>) {
    this.#on.add(cb)
  }

  set off(cb: Callback<T>) {
    if (this.#on.has(cb)) {
      this.#on.delete(cb)
    }
  }

  emit(value: T) {
    for (const cb of this.#on) cb(value)
  }
}