When using an async function in t.throws(), receive errors: "Function returned: Promise {}" and "Unhandled rejection"

[Lukenickerson]

Description

In 1.0.0-beta.8 (with no special configuration or command line arguments) I'm seeing an error with essentially the same function that was posted in #1371.

Test Source

import test from 'ava';

test('test', async (t) => {
  await t.throws(async () => {
    throw new Error();
  });
});

Error Message & Stack Trace

Message returned from running the test says something like:

1 test failed
1 unhandled rejection

Line: await t.throws(async () => {
Function returned: Promise {}

Line: throw new Error();
Unhandled rejection in [test filename]

Environment

Node.js v10.9.0
darwin 17.6.0
AVA 1.0.0-beta.8
npm 6.2.0

[novemberborn]

Ah sorry about that. As of Beta 7, t.throws() only works for synchronous errors. You'll need to change your test to use t.throwsAsync().

However we should provide better feedback in the test output. I've opened #1932 with some pointers.