Robolectric test specification from the commandline:

shell_gradle_class_specifier.groovy

    // Add test classes on the command line. Examples:
    //     gradle test -Dclasses=SomeClassTest          // runs test/java/com/bla/SomeClassTest.java
    //     gradle test -Dclasses=*ActivityTest          // runs all classes who's name ends in ActivityTest.java
    //     gradle test || gradle test -DClasses=all     // both notations include all classes
    def suppliedClasses = System.getProperty('classes', 'all')
    if (suppliedClasses == 'all') {
        println "target: all"
        include '**/*Test.class'
    } else {
        def targetClass = '**/'+suppliedClasses +'.class'
        println "target: " + targetClass
        include targetClass
    }