Array.prototype.forEachNonBlocking

array.ts

export async function forEachNonBlocking<T>(
  arrayOrIterator: IterableIterator<T> | T[],
  fn: (item: T) => void,
  frameBudgetInMillis: number = 10
): Promise<void> {
  const iterator = Array.isArray(arrayOrIterator)
    ? arrayOrIterator[Symbol.iterator]()
    : arrayOrIterator;

  return new Promise((resolve, reject) => {
    function continueIteration() {
      const start = Date.now();
      while (true) {
        const item = iterator.next();

        if (item.done) {
          resolve();
          break;
        }

        try {
          fn(item.value);
        } catch (error) {
          reject(error);
          break;
        }

        if (Date.now() - start > frameBudgetInMillis) {
          setTimeout(continueIteration, 0);
          break;
        }
      }
    }

    continueIteration();
  });
}