How to perform Integration test using Gradle for separate projects?

I have a Java Gradle Project named "code" which conatains Java code which is to be tested. And I have a separate gradle project named "itest" which contains code for the integration testing. And I am building these code using Jenkins.

code -- /src/main/java

Now, in which project I should write task for integration testing in build.gradle file and how should i provide link to the correct project whose java code is to be tested. Can I test code from some other project?