Simple class for subscribable objects with state and multiple subscribers

Subscribable.js

export class Subscribable {
  constructor(name) {
    this._name = name
    this._subscribers = []
    this._state = undefined
  }

  getState() {
    return this._state
  }

  onEvent(fn) {
    this._subscribers.push(fn)
  }

  removeSubscriber(fn) {
    const ix = this._subscribers.indexOf(fn)
    if (ix === -1) {
      console.warn(
        `Attempted to remove subscriber '${fn}' from Subscribable '${this._name}', but subscriber was not found.`
      )
      return
    }

    this._subscribers.splice(ix, 1)
  }

  trigger(value) {
    this._state = value
    for (const s of this._subscribers) {
      s(value)
    }
  }
}

Subscribable.ts

export type Subscriber<T> = (value: T) => void

export class Subscribable<T> {
  private _name: string;
  private _subscribers: Subscriber<T>[] = [];
  private _state: T | undefined = undefined;

  constructor(name: string) {
    this._name = name
  }

  getState() {
    return this._state
  }

  onEvent(fn: Subscriber<T>) {
    this._subscribers.push(fn)
  }

  removeSubscriber(fn: Subscriber<T>) {
    const ix = this._subscribers.indexOf(fn)
    if (ix === -1) {
      console.warn(
        `Attempted to remove subscriber '${fn}' from Subscribable '${this._name}', but subscriber was not found.`
      )
      return
    }

    this._subscribers.splice(ix, 1)
  }

  trigger(value: T) {
    this._state = value
    for (const s of this._subscribers) {
      s(value)
    }
  }
}