Nestjs Repository test fails with error "Received promise resolved instead of rejected" - node.js

Question

I am writing unit tests for my backend application, I am struggling to test for a item in the database not being found, this is the code for my repository to be tested:
#EntityRepository(Collectible)
export class CollectibleRepository extends Repository<Collectible> {
async getCollectible(id: number) {
const collectible = await this.findOne(id);
if (!collectible) {
throw new NotFoundException();
}
return collectible;
}
}
And this is the code for testing, I will only show this test case.
const mockCollectible = new Collectible(
faker.lorem.sentence(),
faker.lorem.sentences(3),
faker.datatype.float(),
faker.datatype.float(),
faker.datatype.number(),
);
describe('Collectible Repository', () => {
let collectibleRepository: CollectibleRepository;
beforeEach(async () => {
const module = await Test.createTestingModule({
providers: [CollectibleRepository],
}).compile();
collectibleRepository = module.get<CollectibleRepository>(
CollectibleRepository,
);
});
describe('View Collectibles', () => {
it('throws and error as the collectible is not found', async (done) => {
collectibleRepository.findOne = jest.fn().mockResolvedValue(undefined);
await expect(collectibleRepository.getCollectible(1)).rejects.toThrow(
NotFoundException,
);
done();
});
});
});
This causes the following error output:
Expected message: not "Not Found"
8 | const collectible = await this.findOne(id, { relations: ['business'] });
9 | if (!collectible) {
> 10 | throw new NotFoundException();
| ^
11 | }
12 | return collectible;
13 | }
at CollectibleRepository.getCollectibleBusiness (src/collectible/collectible.repository.ts:10:13)
(Use `node --trace-warnings ...` to show where the warning was created)
(node:95012) UnhandledPromiseRejectionWarning: Unhandled promise rejection. This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). To terminate the node process on unhandled promise rejection, use the CLI flag `--unhandled-rejections=strict` (see https://nodejs.org/api/cli.html#cli_unhandled_rejections_mode). (rejection id: 3)
(node:95012) [DEP0018] DeprecationWarning: Unhandled promise rejections are deprecated. In the future, promise rejections that are not handled will terminate the Node.js process with a non-zero exit code.
FAIL src/collectible/collectible.repository.spec.ts (8.525 s)
● Collectible Repository › View Collectibles › throws and error as the collectible is not found
expect(received).rejects.not.toThrow()
Received promise resolved instead of rejected
Resolved to value: undefined
39 | it('throws and error as the collectible is not found', async (done) => {
40 | collectibleRepository.findOne = jest.fn().mockResolvedValue(undefined);
> 41 | await expect(collectibleRepository.getCollectible(1)).rejects.not.toThrow(
| ^
42 | NotFoundException,
43 | );
44 | done();
at expect (../node_modules/expect/build/index.js:134:15)
at Object.<anonymous> (collectible/collectible.repository.spec.ts:41:13)
I tried using this repository (which was mentioned in another SO thread) with a set of examples for testing Nest.js applications, but it seems like a repository is not being directly tested.
Update: I updated my code since I was missing a await in my code (as noted by Micael Levi ), I was also calling the wrong function (lol). I am receiving the following warning:
(node:98378) UnhandledPromiseRejectionWarning: Error: expect(received).rejects.not.toThrow(expected)
Though probably I will ignore it unless it affects my CI pipeline (which I need to configure lmao)
Update 2: Warning was caused by another test (I may rest for now).

Answer 1

you missed the await in const collectible = this.findOne(id);
So
const collectible = await this.findOne(id);