The problem I am really having is .includes() method is behaving erratically. I am using it to check if a user entered word is a valid word, like allWords.includes(userWord). It usually returns false, regardless of inclusion of word. allWords is like 12,000 elements or so, I think I need to call it asynchronously.

A simpler version in codesandbox works, but it's always returning false in my react program. I am still new to TS, and async programming. Planning to read a book on it, but want to finish this darn program first.

Here is my async function

//helpers.ts
export async function validateGuess(guess: GuessCharacter[]): Promise<boolean> {

  async function includesPromise(array: string[], word: string) {
    return new Promise<boolean>((resolve) => {
      resolve(array.includes(word));
    });
  }
  
  //each letter of word is in an object
  let word: string = '';

  for (let character of guess) {
    word  = character.value;
  }

  return includesPromise(allWords, word).then((result) => result);
}

Here is where it is called

/// index.ts
  function handleEnterPress() {
    validateGuess(gameState.guesses[gameState.guessCount]).then((response) => {
      if (response) {
        dispatch(ActionKind.Enter);
      } else {
        console.log('Not in word list');
      }
    });

I've also tried

  async function handleEnterPress() {
    let status: boolean = await validateGuess(
      gameState.guesses[gameState.guessCount]
    );
    if (status) {
      dispatch(keyAction.Enter);
    } else {
      console.log('Not in word list');
    }
  }

All help is appreciate. Thanks!

CodePudding user response：

The main issue is that you think this line returns result. It doesn't. It returns the unresolved promise. When the promise gets resolved (because you added a .then() the result is passed in... but then it's lost.

  return includesPromise(allWords, word).then((result) => result);

You could await that to get the value out of the promise. Best to not mix async/await and .then()/.catch().

EDIT: ... and the comments from others are all valid as well.

CodePudding user response：

Your logic looks OK.

A couple of things there:

1. What does gameState.guesses contain? For your logic to work it should be an array of objects with a property called value which should be an iterable
2. If gameState.guesses[i] is a string you should NOT do word = character.value but:
   word = character instead
3. gameState.guessCount should NOT be greater than (gameState.guesses.length - 1) or you will get an undefined value
4. You don't need to use an async operation there once it's going to be an in-memory operation, you won't be doing it any faster nor going to free processing time for other tasks.