Function checkIsPromise

lib/assert.js:587–595

(obj)

}

function checkIsPromise(obj) {
  // Accept native ES6 promises and promises that are implemented in a similar
  // way. Do not accept thenables that use a function as `obj` and that have no
  // `catch` handler.
  return isPromise(obj) ||
    (obj !== null && typeof obj === 'object' &&
    typeof obj.then === 'function' &&
    typeof obj.catch === 'function');
}

async function waitForActual(promiseFn) {
  let resultPromise;