How to debug grade-based unit tests with intellij 14.1.1 and mac platform

I am new to gradle, and just working on a project. I did ./gradlew test and it worked perfectly, shown the logs.

Then I imported it to Intellij, and now picked up the gradle test task, and clicked on debug, but it didn't work. I checked everywhere but didn't find any correct configuration and straight to the point answer. e.g. How to debug gradle based unit tests in Intellij