Refactored_HandlingErrorsInAcmeCompanyApiTest.ts

describe('AcmeCompanyApi', () => {
     // some declarations

    beforeEach(() => {
        decoratedApi = {
            open: jest.fn<Promise<OpeningResult>, [Claim]>()
        };

        api = new WithErrorHandlingCompanyApi(decoratedApi);
        claim = aClaim(causeCodeInClaim);
    });

    it('should fail when token retrieval throws error', async () => {
        when(decoratedApi.open)
            .calledWith(claim)
            .mockImplementation((_) => {
                throw new CannotRetrieveTokenError('Cannot retrieve token')
            });

        const result = await api.open(claim);

        expect(result).toEqual(new FailedOpening(
            claim,
            'Acme API: failure retrieving token'
        ));
    });

    it('should fail when getting causes throws error', async () => {
        when(decoratedApi.open)
            .calledWith(claim)
            .mockImplementation((_) => {
                throw new CannotGetCausesError('Cannot retrieve causes')
            });

        const result = await api.open(claim);

        expect(result).toEqual(new FailedOpening(
            claim,
            'Acme API: failure getting claim causes'
        ));
    });

    it('should fail when finding matching cause throws error', async () => {
        when(decoratedApi.open)
            .calledWith(claim)
            .mockImplementation((_) => {
                throw new CannotFindMatchingCauseError()
            });

        const result = await api.open(claim);

        expect(result).toEqual(new FailedOpening(
            claim,
            'Acme API: cannot find cause for claim 123456789'
        ));
    });

    it('should fail when opening claim throws error', async () => {
        when(decoratedApi.open)
            .calledWith(claim)
            .mockImplementation((_) => {
                throw new CannotOpenClaimError('Cannot open claim')
            });

        const result = await api.open(claim);

        expect(result).toEqual(new FailedOpening(
            claim,
            'Acme API: cannot open claim 123456789'
        ));
    });

    it('should fail when an unknown error occurs', async () => {
        const unknownError = new Error('Unexpected error');
        when(decoratedApi.open)
            .calledWith(claim)
            .mockImplementation((_) => {
                throw unknownError;
            });

        const result = await api.open(claim);

        expect(result).toEqual(new FailedOpening(
            claim,
            'Acme API: Unexpected error'
        ));
    });

    function aClaim(causeCode: string): Claim {
        return new Claim(
            '123456789',
            '123456789',
            new Date('2021-01-01'),
            'Test claim',
            new Customer('Pepe', '+34668522001'),
            causeCode
        );
    }
});