I'm trying to catch an error which should be throw by the function getUserRemendations. This is my example:

it('should throw an error when no user ID is provided', (done) => {
  expect(async () => {
    await Client.getUserRemendations(null, {})
  }).to.throw(/Missing/)
})

Unfortunately it doesn't work and I get as result that my test it doesn't pass along with this message:

AssertionError: expected [Function] to throw an error

I'm trying to catch an error which should be throw by the function getUserRemendations. This is my example:

it('should throw an error when no user ID is provided', (done) => {
  expect(async () => {
    await Client.getUserRemendations(null, {})
  }).to.throw(/Missing/)
})

Unfortunately it doesn't work and I get as result that my test it doesn't pass along with this message:

AssertionError: expected [Function] to throw an error

• javascript
• unit-testing
• async-await
• mocha.js

• 1 Please don't edit solutions into the question, rather post an answer. – Bergi Commented Sep 9, 2016 at 12:46
• Notice that the async/await here is totally useless. expect(() => SClient.getUserRemendations(null, {})) uses a function that returns a promise just as well. – Bergi Commented Sep 9, 2016 at 12:47

1 Answer 1

The way you have set up the the test won't work because expect.to.throw is not expecting a promise. At least I think that is what is going on based on this issue.

The best alternative is to use chai-as-promised and do something like:

it('should throw an error when no user ID is provided', () => {
  expect(Client.getUserRemendations(null, {})).be.rejectedWith(/Missing/);
});