Stub method in grails unit test

Question

I have a unit test that does not seem to pass. :(

{
    given:
    Date currentDate = new Date()
    DateUtils.getCurrentDate() >> currentDate
    BigDecimal amount = 5
    long paymentMethodId = 4L
    Date fiveMinutesBeforeCurrentDate = new Date()

    use (TimeCategory) {
        fiveMinutesBeforeCurrentDate = currentDate-5.minutes
    }

    PaymentDetails details = Mock(PaymentDetails)
    PaymentDetails.findByIdAndAmountAndDateCreatedGreaterThanEquals(paymentMethodId, amount, fiveMinutesBeforeCurrentDate) >> details

    when:
    service.validatePaymentDetails(paymentMethodId, amount)

    then:
    thrown InvalidOperationException
}

The error always seems "No exception was thrown". The method validatePaymentDetails should throw an exception if the value of details is not null.

Thank you for your help!

Answer 1

Given a service like this:

class PaymentService {

    void validatePaymentDetails(long paymentMethodId, BigDecimal amount) {
        if(PaymentDetails.findByIdAndAmountAndDateCreatedGreaterThanEquals(paymentMethodId, amount, new Date()) != null) {
            throw new InvalidOperationException()
        }
    }
}

A unit test that would make sure that InvalidOperationException is thrown whenever PaymentDetails.findByIdAndAmountAndDateCreatedGreaterThanEquals returns something other than null could look like this:

import grails.testing.gorm.DataTest
import grails.testing.services.ServiceUnitTest
import spock.lang.Specification

class PaymentServiceSpec extends Specification implements ServiceUnitTest<PaymentService>, DataTest{

    @Override
    Class[] getDomainClassesToMock() {
        [PaymentDetails]
    }

    void "test payment details validation"() {
        given:
        BigDecimal amount = 5
        long paymentMethodId = 4L

        GroovySpy(PaymentDetails, global: true)

        def details = new PaymentDetails()
        1 * PaymentDetails.findByIdAndAmountAndDateCreatedGreaterThanEquals(_, _, _) >> details

        when:
        service.validatePaymentDetails(paymentMethodId, amount)

        then:
        thrown InvalidOperationException
    }
}

I hope that helps.