Calling assertion block from where

gistfile1.groovy

class AssertionFromWhereSpec extends Specification {

    def 'should execute closure from where'() {

        given:
            Dupa dupa = Mock()
            Cyce cyce = new Cyce(dupa)
        when:
            cyce.asd()
        then:
             1 * dupa.cosTam(*_) >> { args ->
                 assertion(args[1])
                 return 1
             }
        where:
            var1  | assertion
            'asd' | { int value ->  assert value > 100 }

    }

    class Cyce {

        private Dupa dupa

        Cyce(Dupa dupa) {
            this.dupa = dupa
        }

        int asd() {
           return dupa.cosTam('a', 123)
        }
    }

    interface Dupa {
        int cosTam(String a, Integer b)
    }

    class DupaImpl implements Dupa {
        int cosTam(String a, Integer b) {
            return 1
        }
    }

}