scrabble-solver/packages/dictionaries/src/lib/createAsyncProxy.ts

Scrabble Solver 2 - Free, open-source, cross-platform, multi-language analysis tool for Scrabble, Scrabble Duel, Super Scrabble, Letter League, Crossplay, Literaki, and Kelimelik. Quickly find the top-scoring words using the given board and tiles.

type AsyncCallback<T> = () => Promise<T>;

export const createAsyncProxy = <T>(asyncCallback: AsyncCallback<T>): AsyncCallback<T> => {
  let promise: Promise<T> | null = null;

  return async (): Promise<T> => {
    if (promise) {
      return promise;
    }

    try {
      promise = asyncCallback();
      return await promise;
    } finally {
      promise = null;
    }
  };
};