WeakRefMap

WeakRefMap.ts

export class WeakRefMap<K, V extends object> {
  #weakRefs = new Map<K, WeakRef<V>>()
  #registry = new FinalizationRegistry((key) => this.#weakRefs.delete(key))

  has = (key: K) => this.#weakRefs.has(key)
  get = (key: K) => this.#weakRefs.get(key)?.deref()

  set = (key: K, value: V) => {
    const ref = new WeakRef(value)

    this.#weakRefs.delete(key)
    this.#registry.register(value, key, ref)
    this.#weakRefs.set(key, ref)

    return this
  }

  delete = (key: K) => {
    const ref = this.#weakRefs.get(key)

    if (ref) {
      this.#registry.unregister(ref)
    }

    return this.#weakRefs.delete(key)
  }
}