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gistfile1.txt

/* 
  Ensure that multiple calls to the calculateCheap function
  with the same argument will not result in multiple
  calls to the calculateExpensive function.

  Expected console output:
  calculateExpensive called with = 2
  result = 4
  result = 4
  result = 4
*/

async function calculateCheap(num: number): Promise<number> {
  const result = await calculateExpensive(num);
  return result;
}

/*
  ---------------------
  DO NOT EDIT CODE BELOW
  ----------------------
*/

/**
 * Simulates an expensive calculation by doubling the input number after a delay.
 */
async function calculateExpensive(num: number) {
  console.log('calculateExpensive called with =', num);
  return new Promise<number>(resolve =>
    setTimeout(() => resolve(num * 2), 500),
  );
}

function logResult(result: number) {
  console.log('result =', result);
}

calculateCheap(2).then(logResult);
calculateCheap(2).then(logResult);
calculateCheap(2).then(logResult);