How to use the ix/asynciterable.concat function in ix

test('AsyncIterable#catch still throws', async () => {
  const e1 = new Error();
  const er1 = throwError(e1);

  const e2 = new Error();
  const er2 = throwError(e2);

  const e3 = new Error();
  const er3 = throwError(e3);

  const res = catchError(concat(range(0, 2), er1), concat(range(2, 2), er2), er3);

  const it = res[Symbol.asyncIterator]();
  await hasNext(it, 0);
  await hasNext(it, 1);
  await hasNext(it, 2);
  await hasNext(it, 3);
  try {
    await it.next();
  } catch (e) {
    expect(e != null).toBeTruthy();
  }
});

test('AsyncIterable#concat behavior', async () => {
  const res = concat(of(1, 2, 3), of(4, 5));
  expect(await sequenceEqual(res, of(1, 2, 3, 4, 5))).toBeTruthy();
});

test('AsyncIterable#onErrorResumeNext continues after error', async () => {
  const xs = concat(of(1, 2), throwErrpr(new Error()));
  const ys = of(3, 4);

  const res = onErrorResumeNext(xs, ys);
  expect(await sequenceEqual(res, of(1, 2, 3, 4))).toBeTruthy();
});