`throws` doesn't work correctly with promises

[SamVerschueren]

So, I tried to use the throws method in some libraries and found out it doesn't work as it should be or as we expect it should work. Haven't found a solution for this but I have some interesting information (I guess).

Immediately rejected promises

This works correctly, if a promise is rejected immediately, the test is done correctly.

test('immediate rejection', async t => {
    await t.throws(throws(), /help me/);

    function throws() {
        return Promise.reject(new Error('hello world'));
    }
});

Test will fail because hello world !== 'help me'
Note 2: Can't pass in the string help me as second argument of throws because then the test succeeds. But that is another issue.

Long running promises

Think about network requests, etc. This does not work, the throws assertion does not wait untill the promise is rejected or resolved.

test('test me', async t => {
    await t.throws(throws(), /help me/);

    function throws() {
        return new Promise(function (resolve, reject) {
            setTimeout(function () {
                reject(new Error('hello world'));
            }, 2000);
        });
    }
});

This test succeeds.

An interesting thing I noticed is that the test succeeds immediately, it doesn't wait 2 seconds untill the promise is rejected.

Any thoughts?

[SamVerschueren]

Apparently, this prints undefined instead of Promise.

test(t => {
    console.log(t.throws(Promise.resolve()));
    t.end();
});

This is probably the reason why "long running promises" are not working. The await is not working because the returned value is not a promise.

[SamVerschueren]

Can be closed as #127 was merged.