Run JUnit tests in Gradle for Android app

Question

I want to run simple, plain JUnit tests in my Android app project, using Gradle at the same time to write Activity tests afterwards. It took a loong time to configure Gradle and make it work, but, anyway, now I'm stuck trying to make JUnit tests just compile.

I checked this link, but when I run gradle I get the following error:

DummyTest.java:3: error: package junit.
framework does not exist
import junit.framework.Assert;
                      ^
\DummyTest.java:8: error: cannot find symbol
        Assert.assertEquals(5,3);
        ^
  symbol:   variable Assert
  location: class DummyTest

So, junit is not found...

The following is my full gradle.build file:

    buildscript {
    repositories {
        mavenCentral()
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:0.6.+'
    }
}
apply plugin: 'android'

repositories {
    mavenCentral()
}

dependencies {
    compile files('libs/joda-time-2.3.jar')
    compile files('libs/android-support-v4.jar')
    unitTestCompile files("$project.buildDir/classes/release")
    unitTestCompile 'junit:junit:4.8.2'
}

android {
    compileSdkVersion 17
    buildToolsVersion '17.0.0'

    sourceSets {
        main {
            manifest.srcFile 'AndroidManifest.xml'
            java.srcDirs = ['src']
            resources.srcDirs = ['src']
            aidl.srcDirs = ['src']
            renderscript.srcDirs = ['src']
            res.srcDirs = ['res']
        }

        unitTest {
            java.srcDir file('test')
            resources.srcDir file('test/res')
        }
    }
    defaultConfig {
        minSdkVersion 14
        versionName '1.0'
        versionCode 1
        targetSdkVersion 17
    }
}

// add the unitTest task
task unitTest(type:Test, dependsOn: assemble) {
    description = "run unit tests"
    testClassesDir = project.sourceSets.unitTest.output.classesDir
    classpath = project.sourceSets.unitTest.runtimeClasspath
}

build.dependsOn unitTest

Answer 1

AndroidStudio and the new Android Gradle plugin are now offering official unit test support.

This is supported from Android Studio 1.1+ and Android Gradle plugin version 1.1.0+

Dependencies can now be declared as testCompile:

dependencies {
  testCompile 'junit:junit:4.12'
  testCompile "org.mockito:mockito-core:1.9.5"
}

More details here: Unit testing support - Android Tools Project Site.