Gradle build file to set up variables for JaCoCo.

build-jacoco.gradle

/**
 * Created by Nicholas Wong <nickwph@yahoo-inc.com>.
 * Gradle build file to set up variables for JaCoCo.
 * The following tasks will be created in normal circumstance.
 *
 * - Create JaCoCo HTML and XML Reports
 *     jacocoDebug
 *     jacocoRelease
 *
 * - Open JaCoCo HTML Report in Mac OSX
 *     openJacocoHtmlDebug
 *     openJacocoHtmlRelease
 */
apply plugin: 'jacoco'

jacoco.toolVersion = "0.7.4.201502262128"

afterEvaluate {
    android.libraryVariants.each { variant ->
        def variantName = variant.getName()
        def variantNameCapitalized = variantName.capitalize()
        def flavorName = variant.productFlavors[0].getName()
        def buildTypeName = variant.buildType.getName()

        def task = tasks.create(name: "jacoco${variantNameCapitalized}", type: JacocoReport, dependsOn: ["assemble${variantNameCapitalized}", "test${variantNameCapitalized}"]) {
            group = "Report"
            classDirectories = fileTree(
                    dir: "${buildDir}/intermediates/classes/${flavorName}/${buildTypeName}",
                    excludes: ['**/R.class', '**/R$*.class', '**/BuildConfig.*']
            )
            additionalSourceDirs = files(android.sourceSets.main.java.srcDirs)
            sourceDirectories = files(android.sourceSets.main.java.srcDirs)
            executionData = files(["${buildDir}/jacoco/test${variantNameCapitalized}.exec", "jacoco.exec"])
            reports {
                xml.enabled = true
                xml.destination = "${buildDir}/reports/jacoco/${variantName}/index.xml"
                html.enabled = true
                html.destination = "${buildDir}/reports/jacoco/${variantName}"
            }
        }

        tasks.create(name: "openJacocoHtml${variantNameCapitalized}", type: Exec, dependsOn: "jacoco${variantNameCapitalized}") {
            group = "Report"
            executable 'open'
            args "${task.reports.html.destination}/index.html"
        }
    }
}