Robolectric setup with Android Studio

Android Studio: 1.2

1. Add class path to project build.

proejct/buiild.gradle

classpath 'org.robolectric:robolectric-gradle-plugin:1.0.1'

2. Add robolectric plugin to app build.

proejct/app/build.gradle

project/app/build.gradle

apply plugin: 'org.robolectric'

3. Add dependencies to app build.

proejct/app/build.gradle

dependencies {
    compile fileTree(dir: 'libs', include: ['*.jar'])
    compile 'com.android.support:appcompat-v7:22.1.1'
    testCompile 'junit:junit:4.12'
    testCompile 'org.robolectric:robolectric:2.4'
}

4. Add configurations for convenience to app build.

proejct/app/build.gradle

robolectric {
    // Configure includes / excludes
    include '**/*Test.class'
    exclude '**/espresso/**/*.class'

    // Configure max heap size of the test JVM
    maxHeapSize = '2048m'

    // Configure the test JVM arguments - Does not apply to Java 8
    jvmArgs '-XX:MaxPermSize=512m', '-XX:-UseSplitVerifier'

    // Specify max number of processes (default is 1)
    maxParallelForks = 4

    // Specify max number of test classes to execute in a test process
    // before restarting the process (default is unlimited)
    forkEvery = 150

    // configure whether failing tests should fail the build
    ignoreFailures true

    // use afterTest to listen to the test execution results
    afterTest { descriptor, result ->
        println "Executing test for ${descriptor.name} with result: ${result.resultType}"
    }
}

Your gradle build files should look like below:

proejct/build.gradle

buildscript {
    repositories {
        jcenter()
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:1.2.2'

        // NOTE: Do not place your application dependencies here; they belong
        // in the individual module build.gradle files
        classpath 'org.robolectric:robolectric-gradle-plugin:1.0.1'
    }
}

allprojects {
    repositories {
        jcenter()
    }
}

proejct/app/build.gradle

apply plugin: 'com.android.application'
apply plugin: 'org.robolectric'

android {
    compileSdkVersion 22
    buildToolsVersion "22.0.1"

    defaultConfig {
        applicationId "com.spark.eample.robolectrictest"
        minSdkVersion 10
        targetSdkVersion 22
        versionCode 1
        versionName "1.0"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
}

dependencies {
    compile fileTree(dir: 'libs', include: ['*.jar'])
    compile 'com.android.support:appcompat-v7:22.1.1'
    testCompile 'junit:junit:4.12'
    testCompile 'org.robolectric:robolectric:2.4'
}

robolectric {
    // Configure includes / excludes
    include '**/*Test.class'
    exclude '**/espresso/**/*.class'

    // Configure max heap size of the test JVM
    maxHeapSize = '2048m'

    // Configure the test JVM arguments - Does not apply to Java 8
    jvmArgs '-XX:MaxPermSize=512m', '-XX:-UseSplitVerifier'

    // Specify max number of processes (default is 1)
    maxParallelForks = 4

    // Specify max number of test classes to execute in a test process
    // before restarting the process (default is unlimited)
    forkEvery = 150

    // configure whether failing tests should fail the build
    ignoreFailures true

    // use afterTest to listen to the test execution results
    afterTest { descriptor, result ->
        println "Executing test for ${descriptor.name} with result: ${result.resultType}"
    }
}

5. Config Build Variants.

You can find Build Variants panel on the left bottom in your Android Studio. Otherwise, click View>Tool Windows>Build Variants in the main menu. And then change Test Artifact to Unit Tests to use JUnit as default test framework.

6. Write a test code.

Create test folder app/src/textDebug/java. This would be your main test directory and of course, you can create packages under this directory. Here is a sample test code.

package com.spark.eample.robolectrictest;

import org.junit.Before;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.robolectric.Robolectric;
import org.robolectric.RobolectricTestRunner;
import org.robolectric.annotation.Config;

import static org.hamcrest.core.Is.is;
import static org.junit.Assert.assertThat;

@Config(emulateSdk = 18)
@RunWith(RobolectricTestRunner.class)
public class MainModelTest {

    @Before
    public void setUp() throws Exception {
        //Do something for initialisation
    }

    @Test
    public void testGetText() throws Exception {
        assertThat(3+4, is(7));
    }
}

7. Run the test.

Right click on the testGetText() method and click Run 'testGetText'. You will see the test result in the Run panel on the bottom.