JUnit5 Robolectric Extension (Experimental)

This is an experimental project that aims to bridge the gap between JUnit 5 and Robolectric, providing a way to run your Android unit tests using the modern JUnit 5 framework while leveraging Robolectric's in-memory environment.

Key features

• JUnit 5 Compatibility: Run your tests with the latest JUnit 5 features and syntax.

Current Limitations

• Parallel Execution: Parallel test execution only experimentally supported with classes.
• Configuration:
  • Robolectric @Config's sdk parameter annotation can only be set on outermost test class.
  • @GraphicsMode annotations can only be set on outermost test class.
• Experimental Status: This extension is still under development, and its API might change in future versions.

Installation

1. Add the Gradle Plugin Portal and Maven Central and Google's Maven repository to your project's settings.gradle file:

Kotlin

pluginManagement {
    repositories {
        gradlePluginPortal()
        mavenCentral()
        google()
    }
}

dependencyResolutionManagement {
    repositories {
        mavenCentral()
        google()
    }
}

Groovy

pluginManagement {
    repositories {
        gradlePluginPortal()
        mavenCentral()
        google()
    }
}

dependencyResolutionManagement {
    repositories {
        mavenCentral()
        google()
    }
}

2. Enable JUnit Platform Launcher Interceptors and add the dependency to your app or library module's build.gradle:

Kotlin

plugins {
    id("tech.apter.junit5.jupiter.robolectric-extension-gradle-plugin") version ("<latest.release>")
}

Groovy

plugins {
    id 'tech.apter.junit5.jupiter.robolectric-extension-gradle-plugin' version '<latest.release>'
}

Basic usage

1. Annotate your test class with @ExtendWith. This extension will manage the Robolectric environment for your tests:

Kotlin

@ExtendWith(RobolectricExtension::class)

Java

@ExtendWith(RobolectricExtension.class)

2. Utilize the standard JUnit 5 annotations (@Test, @BeforeEach, @AfterEach, etc.) within your test methods. You could also use org.jetbrains.kotlin:kotlin-test-junit5 package if you want to.

Kotlin

import android.app.Application
import android.content.Context
import androidx.test.core.app.ApplicationProvider
import org.junit.jupiter.api.AfterAll
import org.junit.jupiter.api.AfterEach
import org.junit.jupiter.api.Assertions.assertInstanceOf
import org.junit.jupiter.api.Assertions.assertTrue
import org.junit.jupiter.api.BeforeAll
import org.junit.jupiter.api.BeforeEach
import org.junit.jupiter.api.Test
import org.junit.jupiter.api.extension.ExtendWith
import org.robolectric.annotation.Config
import tech.apter.junit.jupiter.robolectric.RobolectricExtension

@ExtendWith(RobolectricExtension::class)
@Config(application = RobolectricExtensionSelfTest.MyTestApplication::class)
class RobolectricExtensionSelfTest {

    @BeforeEach
    fun setUp() {
    }

    @AfterEach
    fun tearDown() {
    }

    @Test
    fun shouldInitializeAndBindApplicationAndCallOnCreate() {
        val application = ApplicationProvider.getApplicationContext<Context>()
        assertInstanceOf(MyTestApplication::class.java, application)
        assertTrue((application as MyTestApplication).onCreateWasCalled)
    }

    companion object {
        @BeforeAll
        @JvmStatic
        fun setUpClass() {
        }

        @AfterAll
        @JvmStatic
        fun tearDownClass() {
        }
    }

    class MyTestApplication : Application() {
        internal var onCreateWasCalled = false

        override fun onCreate() {
            this.onCreateWasCalled = true
        }
    }
}

Java

import android.app.Application;

import androidx.test.core.app.ApplicationProvider;

import org.junit.jupiter.api.AfterAll;
import org.junit.jupiter.api.AfterEach;
import org.junit.jupiter.api.Assertions.assertInstanceOf;
import org.junit.jupiter.api.Assertions.assertTrue;
import org.junit.jupiter.api.BeforeAll;
import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.Test;
import org.junit.jupiter.api.extension.ExtendWith;
import org.robolectric.annotation.Config;

import tech.apter.junit.jupiter.robolectric.RobolectricExtension;

import static org.junit.jupiter.api.Assertions.assertInstanceOf;
import static org.junit.jupiter.api.Assertions.assertTrue;

@ExtendWith(RobolectricExtension.class)
@Config(application = RobolectricExtensionSelfTest.MyTestApplication::class)
public class RobolectricExtensionSelfTest {

    @BeforeEach
    public void setUp() {
    }

    @AfterEach
    public void tearDown() {
    }

    @Test
    public void shouldInitializeAndBindApplicationAndCallOnCreate() {
        final Application application = ApplicationProvider.getApplicationContext();
        assertInstanceOf(MyTestApplication.class, application);
        assertTrue(((MyTestApplication) application).onCreateWasCalled);
    }

    @BeforeAll
    public static void setUpClass() {
    }

    @AfterAll
    public static void tearDownClass() {
    }

    static class MyTestApplication extends Application {
        public boolean onCreateWasCalled = false;

        @Override
        public void onCreate() {
            this.onCreateWasCalled = true;
        }
    }
}