Method waitFor

lib/internal/test_runner/test.js:437–489

(condition, options = kEmptyObject)

  }

  waitFor(condition, options = kEmptyObject) {
    validateFunction(condition, 'condition');
    validateObject(options, 'options');

    const {
      interval = 50,
      timeout = 1000,
    } = options;

    validateNumber(interval, 'options.interval', 0, TIMEOUT_MAX);
    validateNumber(timeout, 'options.timeout', 0, TIMEOUT_MAX);

    const { promise, resolve, reject } = PromiseWithResolvers();
    const noError = Symbol();
    let cause = noError;
    let pollerId;
    let timeoutId;
    const done = (err, result) => {
      clearTimeout(pollerId);
      clearTimeout(timeoutId);

      if (err === noError) {
        resolve(result);
      } else {
        reject(err);
      }
    };

    timeoutId = setTimeout(() => {
      // eslint-disable-next-line no-restricted-syntax
      const err = new Error('waitFor() timed out');

      if (cause !== noError) {
        err.cause = cause;
      }

      done(err);
    }, timeout);

    const poller = async () => {
      try {
        const result = await condition();

        done(noError, result);
      } catch (err) {
        cause = err;
        pollerId = setTimeout(poller, interval);
      }
    };

    poller();
    return promise;
  }
}

class SuiteContext {