Testing environment Before you proceed the process, Java 1.8 should be installed first in your system. Here is my testing system: OS: MacOSX Yosemite(Version 10.10.3) Android Studio: Version 1.2 Java SDK: Version 1.8.0_45 Project structure /Project /app /src /main /java AndroidManifest.xml /testDebug /java build.gradle /build /gradle build.gradle Configuration /Project/build.gradle Add dependencies for retrolambda and robolectric plugins under dependencies block. buildscript { repositories { jcenter() } dependencies { classpath 'com.android.tools.build:gradle:1.2.2' classpath 'me.tatarka:gradle-retrolambda:3.1.0' classpath 'org.robolectric:robolectric-gradle-plugin:1.0.1' } } allprojects { repositories { jcenter() } } Configuration /Project/app/build.gradle apply plugin: 'co...