No default error when promise.reject() no params

[yoghurtxu]

Hi,
the await-to-js readme does not mention the different between using method 1(try catch) and method 2(await-to-js).
but their use in reject is different.

For example:

function returnPromise() {
    return Promise.reject();
}

1.when use try catch：

try {
   const res = await this.returnPromise();
   console.log("res", res);
   console.log("first case normal process");
 } catch (err) {
   console.log("err", err);
   console.log("first case abnormal process");
 }

err is undefined,but "first case abnormal process" can output normally.

2.when use await-to-js

const [err, res] = await to(this.returnPromise());
 if (res) {
   console.log("res", res);
   console.log("second case normal process");
 } else if (err) {
   console.log("err", err);
   console.log("second case abnormal process");
}

err is undefined, so "second case abnormal process" cannot output normally.

Expect:

if await-to-js error is undefined, return default error(new Error() or other).