Spock - Testing that 2nd call throws exception

Question

I have a function that given certain initial inputs, the first call should work properly, but the second call should throw a custom exception. The corresponding spock/groovy code looks similar to the following (generalized):

def 'test'() {
    given:
    def serviceID1 = genarateID()
    def serviceID2 = generateID()
    serviceUnderTest.foo(serviceID1) // This should be fine.
    
    when:
    serviceUnderTest.foo(serviceID2) // This should throw a custom exception
    
    then:
    CustomException e = thrown()
    //some verification code on e goes here.
}

What... seems to be happening is that the thrown() seems to be matching up against the first call rather than the second call. Is there a way to properly do this in spock? I was thrown off for a while because my ide was fine with it but gradlew was telling me of failures until I changed my ide to use gradle to run tests, but I'm not sure how to fix what I'm trying to test.

Answer 1

This reproducer works fine and does what you describe you want to test.

import spock.lang.*

class ASpec extends Specification {
  def "hello world"() {
    given:
        def service = new Service()
        
    and:
        service.doTheThing("ok")
      
    when:
        service.doTheThing("fails")
      
    then:
        RuntimeException e = thrown()
  }
}

class Service  {
    int invocations = 0
    
    void doTheThing(String arg) {
        if (invocations++ == 1) {
            throw new RuntimeException()
        }
    }
}

Try it in the Groovy Web Console

Unless it is really necessary to test them both in order, I would suggest to split your tests into two, as you are testing two separate things.