Can't use PowerMock with Robolectric and Gradle (android)

Question

I tried to use PowerMock with Robolectric to mock a static method in my android project. I am using gradle. But I am getting the following exception:

Caused by: java.lang.IllegalStateException: PowerMockRule can only be used with the system classloader but was loaded by org.robolectric.bytecode.AsmInstrumentingClassLoader@7e61b85
at org.powermock.modules.junit4.rule.PowerMockRule.<clinit>(PowerMockRule.java:35)
... 47 more

My test class looks like that:

...
import org.junit.Rule;
import org.powermock.api.mockito.PowerMockito;
import org.powermock.modules.junit4.rule.PowerMockRule;
import org.powermock.modules.agent.PowerMockAgent;
import org.powermock.core.classloader.annotations.*;
import org.powermock.core.classloader.annotations.PowerMockIgnore;
import org.powermock.modules.junit4.rule.PowerMockRule;

@RunWith(RobolectricTestRunner.class)
@PowerMockIgnore({ "org.mockito.*", "org.robolectric.*", "android.*" })
@Config(manifest = "./src/main/AndroidManifest.xml",emulateSdk = 18)
public class MyTest {

    @Rule
    public PowerMockRule rule = new PowerMockRule();


    @Test
    public void test() {
       ...
    }
}

The full gradle file (some really not related stuff was removed):

apply plugin: 'com.android.application'

String[][] allowedFlavorCombinations = [
        ...
];

android.variantFilter { variant ->
    boolean buildVariant = false;
    for (int i = 0; i < allowedFlavorCombinations.length; i++) {
        if(allowedFlavorCombinations[i][0].equalsIgnoreCase(variant.getFlavors().get(0).name)
                && allowedFlavorCombinations[i][1].equalsIgnoreCase(variant.getFlavors().get(1).name)) {
            buildVariant = true;
        }
    }
    variant.setIgnore(!buildVariant);
}

android {
    compileSdkVersion 20
    buildToolsVersion "20"

    defaultConfig {
        minSdkVersion 11
        targetSdkVersion 20
        versionCode=139
        versionName="3.0"
    }

    sourceSets {
        instrumentTest.setRoot('src/test')
    }

    packagingOptions {
        exclude 'META-INF/LICENSE.txt'
        exclude 'META-INF/NOTICE.txt'
    }

    lintOptions {
        checkReleaseBuilds false
        abortOnError false
    }

    signingConfigs {
        release
    }
    buildTypes {
        release {
            minifyEnabled false
            signingConfig signingConfigs.release
            applicationVariants.all { variant ->
                variant.outputs.each  { output ->
                    output.outputFile = new File(output.outputFile.parent, output.outputFile.name.replace(".apk", "-" + defaultConfig.versionName + ".apk"))
                }
            }
        }
    }

    if (project.hasProperty('storeFile') &&
            project.hasProperty('storePassword') &&
            project.hasProperty('keyPassword')) {
        android.signingConfigs.release.storeFile = file(storeFile)
        android.signingConfigs.release.storePassword = storePassword
        android.signingConfigs.release.keyPassword = keyPassword
        android.signingConfigs.release.keyAlias = keyAlias
    } else {
        buildTypes.release.signingConfig = null
    }

    flavorDimensions "client", "settings"

    productFlavors {
        ...
    }
}

sourceSets {
    unitTest {
        java.srcDir file('src/test/java')
        resources.srcDir file('src/test/res')
    }
}

configurations {
    unitTestCompile.extendsFrom runtime
    unitTestRuntime.extendsFrom unitTestCompile
}

dependencies {
    compile 'com.android.support:appcompat-v7:20.0.0'
    compile 'com.android.support:recyclerview-v7:21.0.0'
    compile 'com.google.code.gson:gson:2.3'
    compile 'com.google.android.gms:play-services:6.1.71'
    compile 'com.android.support:support-v4:21.0.0'
    compile 'com.nineoldandroids:library:2.4.0'
    compile 'com.android.support:gridlayout-v7:21.0.+'
    compile fileTree(dir: 'libs', include: ['*.jar', '*.aar'])

    unitTestCompile files("$project.buildDir/intermediates/classes/testbase/debug/")
    ...
    unitTestCompile 'junit:junit:4.11'
    unitTestCompile 'com.loopj.android:android-async-http:1.4.6'
    unitTestCompile('org.robolectric:robolectric:2.3:jar-with-dependencies') {
        exclude module: 'support-v4'
    }
    unitTestCompile 'com.google.android:android:4.1.1.4'
    unitTestCompile 'org.mockito:mockito-core:1.10.8'
    unitTestCompile 'org.powermock:powermock-api-mockito:1.6.1'
    unitTestCompile 'org.powermock:powermock-module-junit4-rule-agent:1.6.1'
    unitTestCompile 'org.powermock:powermock-module-junit4-rule:1.6.1'
    unitTestCompile 'org.powermock:powermock-module-junit4:1.6.1'
    unitTestCompile 'com.android.support:appcompat-v7:20.0.0'
    unitTestCompile 'com.google.code.gson:gson:2.3'
    unitTestCompile 'com.google.android.gms:play-services:6.1.71'
    unitTestCompile 'com.android.support:support-v4:21.0.0'
    unitTestCompile 'joda-time:joda-time:2.5'
    unitTestCompile fileTree(dir: 'libs', include: ['*.jar', '*.aar'])

    instrumentTestCompile 'junit:junit:4.11'
    instrumentTestCompile('org.robolectric:robolectric:2.3:jar-with-dependencies') {
        exclude module: 'support-v4'
    }
}

task unitTest(type:Test, dependsOn: [assembleDefault, ':AndroidUtilitiesLibrary:unitTest', ':AndroidUraLibrary:unitTest']) {
    testClassesDir = project.sourceSets.unitTest.output.classesDir
    classpath = project.sourceSets.unitTest.runtimeClasspath
}
check.dependsOn unitTest

In addition there is a top level build file (as we have several modules)

// Top-level build file where you can add configuration options common to all sub-projects/modules.
buildscript {
    repositories {
           jcenter()

    }
    dependencies {
        classpath 'com.android.tools.build:gradle:1.0.0'
        classpath 'com.jakewharton.sdkmanager:gradle-plugin:0.12.0'
    }
}

subprojects {
    apply plugin: 'android-sdk-manager'
}

allprojects {
    repositories {
           jcenter()
    }
}

Has anyone experience in using Powermockito for Robolectric-based unit tests for Android? Any idea what I might be doing wrong?

Answer 1

I created an example project which integrates Robolectric 3 + RobolectricGradleTestRunner + PowerMock + Mockito.

build.gradle:

dependencies {

    ...

    testCompile "org.powermock:powermock-module-junit4:1.6.2"
    testCompile "org.powermock:powermock-module-junit4-rule:1.6.2"
    testCompile "org.powermock:powermock-api-mockito:1.6.2"
    testCompile "org.powermock:powermock-classloading-xstream:1.6.2"
}

Test class:

@RunWith(RobolectricGradleTestRunner.class)
@Config(constants = BuildConfig.class, sdk = 18)
@PowerMockIgnore({ "org.mockito.*", "org.robolectric.*", "android.*" })
@PrepareForTest(Static.class)
public class DeckardActivityTest {

    @Rule
    public PowerMockRule rule = new PowerMockRule();

    @Test
    public void testStaticMocking() {
        PowerMockito.mockStatic(Static.class);
        Mockito.when(Static.staticMethod()).thenReturn("hello mock");

        assertTrue(Static.staticMethod().equals("hello mock"));
    }
}