Function setter

packages/context/src/value-promise.ts:102–108

(key: string)

  let asyncResolvers: PromiseLike<void>[] | undefined = undefined;

  const setter = (key: string) => (val: V) => {
    if (val !== undefined) {
      // Only set the value if it's not undefined so that the default value
      // for a key will be honored
      result[key] = val;
    }
  };

  for (const key in map) {
    const valueOrPromise = resolver(map[key], key, map);