Runtime Exception Mocking groovy.sql in Spock

Question

I've scoured around StackOverflow and Google for a while trying to find the right configuration/syntax for being able to run this code in a Spock Specification:

Sql mockSql = Mock()

However when I run the unit test, I get a nasty exception thrown in my face by CGLIB:

java.lang.IllegalAccessError: tried to access method groovy.sql.Sql.<init>()V from class groovy.sql.Sql$$EnhancerByCGLIB$$d0b7cd7f
at org.spockframework.mock.runtime.MockInstantiator.instantiate(MockInstantiator.java:33)
at org.spockframework.mock.runtime.ProxyBasedMockFactory$CglibMockFactory.createMock(ProxyBasedMockFactory.java:92)
at org.spockframework.mock.runtime.ProxyBasedMockFactory.create(ProxyBasedMockFactory.java:49)
at org.spockframework.mock.runtime.JavaMockFactory.create(JavaMockFactory.java:51)
at org.spockframework.mock.runtime.CompositeMockFactory.create(CompositeMockFactory.java:44)
at org.spockframework.lang.SpecInternals.createMock(SpecInternals.java:47)
at org.spockframework.lang.SpecInternals.createMockImpl(SpecInternals.java:282)
at org.spockframework.lang.SpecInternals.MockImpl(SpecInternals.java:83)

I looked at this question/answer - Mock static method with GroovyMock or similar in Spock - hoping it might give me a good starting point, but the class being mocked in my case, groovy.Sql IS a groovy class, so I'm not sure it's the right place to start.

I've successfully tested Groovy.Sql in other unit tests using GroovyMock, but I was hoping maybe I just missed something that can make it so that I can have Spock magic and Groovy SQL all happy together. My apologies if I just missed the answer somewhere - hopefully I'm not repeating someone else's inquiry.

Answer 1

When mocking classes (rather than interfaces) with Spock, putting objenesis-1.2 or higher on the test runtime class path is recommended (in addition to CGLIB) . Otherwise, Spock won't be able to avoid executing the constructor of the class to be mocked, which may have undesired side effects.