How to properly make mock throw an error in Jest?
Change .mockReturnValue with .mockImplementation:
yourMockInstance.mockImplementation(() => { throw new Error();});If it's a promise you can also to .rejects www.jestjs.io/docs/en/asynchronous#resolves--rejects
For Angular + Jest:
import { throwError } from 'rxjs';yourMockInstance.mockImplementation(() => { return throwError(new Error('my error message'));});
For promises, can use https://jestjs.io/docs/mock-function-api#mockfnmockrejectedvaluevalue
test('async test', async () => { const asyncMock = jest.fn().mockRejectedValue(new Error('Async error')); await asyncMock(); // throws "Async error"});For handling thrown errors, can use https://eloquentcode.com/expect-a-function-to-throw-an-exception-in-jest on how to handle it
const func = () => { throw new Error('my error')}it('should throw an error', () => { expect(func).toThrow()})