SWR Cache

simple-cache.ts

// createCache.ts
export default function createCache(fetchFunction: () => Promise<any>, refreshInterval: number, retryAfter: number) {
  let fetchPromise: null | ReturnType<typeof fetchFunction> = null;

  const doThinInInterval = () => {
    fetchFunction().then((data) => {
      fetchPromise = Promise.resolve(data);
    })
    .catch(() => setTimeout(doThinInInterval, retryAfter));
    
  }

  setInterval(doThinInInterval, refreshInterval);


  return () => {
    if (!fetchPromise) {
      fetchPromise = fetchFunction();
    }

    return fetchPromise;
  }
}



// identity-token.ts
//import createCache from './createCache';

async function fetchSsmSecretAndIdentityToken(timeout: number): Promise<string> {
  const timeoutPromise = new Promise((resolve, reject) => setTimeout(reject, timeout));

  try {
    const x = Promise.race(['abcdef', timeoutPromise]);
    return x;
  }
  catch(e) {
    throw new Error('')
  }
}

const cache = createCache(fetchSsmSecretAndIdentityToken, 10_000_000, 5_000)

const x = await cache();