signal-desktop/ts/services/singleServePromise.ts

// Copyright 2022 Signal Messenger, LLC
// SPDX-License-Identifier: AGPL-3.0-only

import { v4 as generateUuid } from 'uuid';

import type { ExplodePromiseResultType } from '../util/explodePromise';

export type SingleServePromiseIdString = string & { __single_serve: never };

// This module provides single serve promises in a pub/sub manner.
// One example usage is if you're calling a redux action creator but need to
// await some result within it, you may pass in this promise and access it in
// other parts of the app via its referencing UUID.

const promises = new Map<
  SingleServePromiseIdString,
  // eslint-disable-next-line @typescript-eslint/no-explicit-any
  ExplodePromiseResultType<any>
>();

export function set<T>(
  explodedPromise: ExplodePromiseResultType<T>
): SingleServePromiseIdString {
  let uuid = generateUuid() as SingleServePromiseIdString;

  while (promises.has(uuid)) {
    uuid = generateUuid() as SingleServePromiseIdString;
  }

  promises.set(uuid, {
    promise: explodedPromise.promise,
    resolve: value => {
      promises.delete(uuid);
      explodedPromise.resolve(value);
    },
    reject: err => {
      promises.delete(uuid);
      explodedPromise.reject(err);
    },
  });

  return uuid;
}

export function get<T>(
  uuid: SingleServePromiseIdString
): ExplodePromiseResultType<T> | undefined {
  return promises.get(uuid);
}