Android test code coverage with JaCoCo Gradle plugin

I'm new to Gradle and Android testing but I've already converted my Android project to build with Gradle.

Now I'm trying to perform test coverage of an Android project with Gradle's JaCoCo plugin.

I've added the following to my build.gradle file:

apply plugin: 'jacoco'

And when I run "gradle jacocoTestReport" the following error:

Task 'jacocoTestReport' not found in root project '<project name>'.

From the documentation I'm supposed to also apply plugin 'java' but it conflicts with plugin 'android'.

Is there a way around this?

Thanks in advance.

Here is how I'm using Jacoco:

buildscript {
  repositories {
    mavenLocal()
    mavenCentral()
  }
  dependencies {
    classpath 'com.android.tools.build:gradle:0.12.+'
    classpath 'org.robolectric:robolectric-gradle-plugin:0.11.+'
  }
}

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

android {
  compileSdkVersion 20
  buildToolsVersion "20.0.0"

  defaultConfig {
    applicationId "YOUR_PACKAGE_NAME"
    minSdkVersion 10
    targetSdkVersion 20
    testHandleProfiling true
    testFunctionalTest true
  }
  buildTypes {
    debug {
      testCoverageEnabled false
    }
    release {
      runProguard false
      proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.txt'
    }
  }
  jacoco {
    version "0.7.1.201405082137"
  }
  packagingOptions {
    exclude 'META-INF/DEPENDENCIES.txt'
    exclude 'META-INF/LICENSE.txt'
    exclude 'META-INF/NOTICE.txt'
    exclude 'META-INF/NOTICE'
    exclude 'META-INF/LICENSE'
    exclude 'META-INF/DEPENDENCIES'
    exclude 'META-INF/notice.txt'
    exclude 'META-INF/license.txt'
    exclude 'META-INF/dependencies.txt'
    exclude 'META-INF/LGPL2.1'
    exclude 'META-INF/services/javax.annotation.processing.Processor'
    exclude 'LICENSE.txt'
  }
}

robolectric {
  include '**/*Test.class'
  exclude '**/espresso/**/*.class'

  maxHeapSize "2048m"
}

jacoco {
  toolVersion "0.7.1.201405082137"
}

// Define coverage source.
// If you have rs/aidl etc... add them here.
def coverageSourceDirs = [
    'src/main/java',
]

task jacocoTestReport(type: JacocoReport, dependsOn: "connectedDebugAndroidTest") {
  group = "Reporting"
  description = "Generate Jacoco coverage reports after running tests."
  reports {
    xml.enabled = true
    html.enabled = true
  }
  classDirectories = fileTree(
      dir: './build/intermediates/classes/debug',
      excludes: ['**/R*.class',
                 '**/*$InjectAdapter.class',
                 '**/*$ModuleAdapter.class',
                 '**/*$ViewInjector*.class'
      ])
  sourceDirectories = files(coverageSourceDirs)
  executionData = files("$buildDir/jacoco/testDebug.exec")
  // Bit hacky but fixes https://code.google.com/p/android/issues/detail?id=69174.
  // We iterate through the compiled .class tree and rename $$ to $.
  doFirst {
    new File("$buildDir/intermediates/classes/").eachFileRecurse { file ->
      if (file.name.contains('$$')) {
        file.renameTo(file.path.replace('$$', '$'))
      }
    }
  }
}


dependencies {
  androidTestCompile('junit:junit:4.11') {
    exclude module: 'hamcrest-core'
  }
  androidTestCompile('org.robolectric:robolectric:2.3') {
    exclude module: 'classworlds'
    exclude module: 'maven-artifact'
    exclude module: 'maven-artifact-manager'
    exclude module: 'maven-error-diagnostics'
    exclude module: 'maven-model'
    exclude module: 'maven-plugin-registry'
    exclude module: 'maven-profile'
    exclude module: 'maven-project'
    exclude module: 'maven-settings'
    exclude module: 'nekohtml'
    exclude module: 'plexus-container-default'
    exclude module: 'plexus-interpolation'
    exclude module: 'plexus-utils'
    exclude module: 'wagon-file'
    exclude module: 'wagon-http-lightweight'
    exclude module: 'wagon-http-shared'
    exclude module: 'wagon-provider-api'
    exclude group: 'com.android.support', module: 'support-v4'
  }
}

The above code also contains a workaround for https://code.google.com/p/android/issues/detail?id=69174.

More details: http://chrisjenx.com/gradle-robolectric-jacoco-dagger/

I'm using JaCoCo with a project using RoboGuice, Butterknife and Robolectric. I was able to set it up using @Hieu Rocker's solution, however there were some minor drawbacks i.e. in our project we use flavors and have some extra tests for those flavors as well as extra java code for each of them. We also use different build types. Therefore a solution to rely on the "testDebug" task was not good enough. Here's my solution: In build.gradle in app module add

apply from: '../app/jacoco.gradle'

Then create a jacoco.gradle file inside of app module with the following content:

    apply plugin: 'jacoco'

    jacoco {
        toolVersion "0.7.1.201405082137"
    }

    def getFlavorFromVariant(String variantName) {
        def flavorString = variantName.replaceAll(/(.*)([A-Z].*)/) { all, flavorName, buildTypeName ->
           flavorName
        }
        return flavorString;
    }

    def getBuildTypeFromVariant(String variantName) {
        def buildTypeString = variantName.replaceAll(/(.*)([A-Z].*)/) { all, flavorName, buildTypeName ->
            "${buildTypeName.toLowerCase()}"
        }
        return buildTypeString;
    }

    def getFullTestTaskName(String variantName) {
        return "test${variantName.capitalize()}UnitTest";
    }

    android.applicationVariants.all { variant ->
        def variantName = variant.name;
        def flavorFromVariant = getFlavorFromVariant("${variantName}");
        def buildTypeFromVariant = getBuildTypeFromVariant("${variantName}");
        def testTaskName = getFullTestTaskName("${variantName}")

        task ("jacoco${variantName.capitalize()}TestReport", type: JacocoReport, dependsOn: testTaskName) {
            group = "Reporting"
            description = "Generate JaCoCo coverage reports after running tests for variant: ${variantName}."
            reports {
                xml.enabled = true
                html.enabled = true
            }

            classDirectories = fileTree(
                    dir: "./build/intermediates/classes/${flavorFromVariant}/${buildTypeFromVariant}",
                    excludes: ['**/R*.class',
                               '**/*$InjectAdapter.class',
                               '**/*$ModuleAdapter.class',
                               '**/*$ViewInjector*.class'
                    ]
            )

            logger.info("Configuring JaCoCo for flavor: ${flavorFromVariant}, buildType: ${buildTypeFromVariant}, task: ${testTaskName}");

            def coverageSourceDirs = [
                    '../app/src/main/java',
                    "../app/src/${flavorFromVariant}/java"
            ]
            sourceDirectories = files(coverageSourceDirs)
            executionData = files("$buildDir/jacoco/${testTaskName}.exec")
            // Bit hacky but fixes https://code.google.com/p/android/issues/detail?id=69174.
            // We iterate through the compiled .class tree and rename $$ to $.
            doFirst {
                new File("$buildDir/intermediates/classes/").eachFileRecurse { file ->
                    if (file.name.contains('$$')) {
                        file.renameTo(file.path.replace('$$', '$'))
                    }
                }
            }
        }
    }

You can execute it from command line like this:

.gradlew jacocoFlavor1DebugTestReport

or

.gradlew jacocoOtherflavorPrereleaseTestReport

In our project we use a convention not to use capital letter inside of flavor and build type names, but if your project does not follow this convention you can simply change getFlavorFromVariant(..) and getBuildTypeFromVariant(..) functions

Hope this helps someone