[SOLVED] How do tell JS that my api fetch link is NOT ok when it thinks it is?

How do tell JS that my api fetch link is NOT ok when it thinks it is?

I'm having this issue with certain API's, where invalid links are still "ok". Here for the ticker symbol I typed a bunch of random letters in place of an actual ticker: ...ticker=AAsdfsPL... as opposed to ...ticker=AAPL... The API link itself still doesn't produce an error even though it doesn't really fetch any data. Any way to fix this or do I need to use a different API?

const resStock = await fetch(
      `https://api.polygon.io/v3/reference/tickers?ticker=AAsdfsPL&active=true&apiKey=key`
    );
    console.log(resStock.ok); //still returns true even though link doesn't do anything.

Solution

In this particular case, you can check for the count property in the returned JSON to determine whether the result is valid or not:

(async function () {
  const resStock = await fetch(
    `https://api.polygon.io/v3/reference/tickers?ticker=AAPsL&active=true&apiKey=6P2qV_oNdXnkkmnd5Vb5VtQWi09OIzfU`
  );
  let json;
  try {
    json = await resStock.json();
  } catch (e) {
    // Ignored
  }
  const isOk = json && !!json.count;
  console.log(isOk);
})();

Documentation: https://polygon.io/docs/stocks/get_v3_reference_tickers