Jacoco: Report not generated for android project

Question

I just integrated Jacoco code coverage for junit and UI test in my android studio project.

I added following steps:

In my app level build.gradle file:

apply plugin: 'jacoco'

and then added below code inside android { }

debug {
            testCoverageEnabled = true
            enableAndroidTestCoverage = true
            enableUnitTestCoverage = true
        }

and then added below code:

jacoco {
    toolVersion = "0.8.8"
}

tasks.withType(Test).configureEach {
    jacoco {
        excludes = [
                "**/R.class",
                "**/R\$*.class",
                "**/BuildConfig.*",
                "**/Manifest*.*",
                "**/*Test*.*"
        ]
    }
}


android {
    // Iterate over all application variants (e.g., debug, release)
    applicationVariants.configureEach { variant ->
        // Extract variant name and capitalize the first letter
        def variantName = variant.name.capitalize()

        // Define task names for unit tests and Android tests
        def unitTests = "test${variantName}UnitTest"
        def androidTests = "connected${variantName}AndroidTest"

        // Register a JacocoReport task for code coverage analysis
        tasks.register("Jacoco${variantName}CodeCoverage", JacocoReport) {
            // Depend on unit tests and Android tests tasks
            dependsOn(unitTests, androidTests)

            // Set task grouping and description
            group = "Reporting"
            description = "Execute UI and unit tests, generate and combine Jacoco coverage report"

            // Configure reports to generate both XML and HTML formats
            reports {
                xml.required = true
                xml.outputLocation = layout.buildDirectory.file("jacoco/xml/${variantName}Coverage.xml")

                html.required = true
                html.outputLocation = layout.buildDirectory.dir("jacoco/html/${variantName}Coverage.html")
            }

            // Set source directories to the main source directory
            sourceDirectories.setFrom(layout.projectDirectory.dir("src/main"))

            // Set class directories to compiled Java and Kotlin classes, excluding specified exclusions
            classDirectories.setFrom(files(
                    fileTree(dir: layout.buildDirectory.dir("intermediates/javac/")) {
                        exclude "**/R.class", "**/R\$*.class", "**/BuildConfig.*", "**/Manifest*.*", "**/*Test*.*"
                    },
                    fileTree(dir: layout.buildDirectory.dir("tmp/kotlin-classes/")) {
                        exclude "**/R.class", "**/R\$*.class", "**/BuildConfig.*", "**/Manifest*.*", "**/*Test*.*"
                    }
            ))

            // Collect execution data from .exec and .ec files generated during test execution
            executionData.setFrom(files(
                    fileTree(dir: layout.buildDirectory) { include "**/*.exec", "**/*.ec" }
            ))
        }
    }
}

But still code coverage report not generated in my android studio.

Answer 1

1. Adding JaCoCo Plugin

   JaCoCo is enabled by adding the following to build.gradle:

   apply plugin: 'jacoco'

2. Configuring JaCoCo:

   JaCoCo is configured to include/exclude specific files in build.gradle:

> tasks.register('jacocoDebugReport', JacocoReport) {
>     dependsOn 'connectedDebugAndroidTest'  // Ensure tests run before generating the report
>     reports {
>         xml.required.set(true)
>         html.required.set(true)
>     }
> 
>     def fileFilter = [
>             '**/R.class', '**/R$*.class', '**/BuildConfig.*', '**/Manifest*.*',
>             '**/*Test*.*', 'android/**/*.*' // Exclude this specific test class
>     ]
> 
>     def debugTree = fileTree(dir: "${buildDir}/intermediates/javac/Debug", excludes:
> fileFilter)
>     def kotlinDebugTree = fileTree(dir: "${buildDir}/tmp/kotlin-classes/Debug", excludes:
> fileFilter)
> 
>     sourceDirectories.setFrom(files("${project.projectDir}/src/main/java"))
>     classDirectories.setFrom(files([debugTree, kotlinDebugTree]))
>     executionData.setFrom(fileTree(dir: "${buildDir}/outputs/code_coverage/DebugAndroidTest/connected/",
> includes: ["**/*.ec"])) }

3. Enabling Code Coverage in android {} Block Inside android {} and debug {}, enable test coverage:

testCoverageEnabled = true
enableAndroidTestCoverage = true
enableUnitTestCoverage = true

4. Sync Gradle and Run Tests:

After configuring JaCoCo, sync Gradle and execute test cases.

5. Running Tests and Generating Reports:

For a Single Class Test in CommunitySetupTestInCompose

 > ./gradlew clean  
./gradlew connectedDebugAndroidTest
    > -Pandroid.testInstrumentationRunnerArguments.class=com.android.test.TestInComposeClass
    > ./gradlew jacocoDebugReport
    > -Pandroid.testInstrumentationRunnerArguments.class=com.android.test.TestInComposeClass

For All Test Cases

> > ./gradlew clean ./gradlew connectedDebugAndroidTest ./gradlew
>     > jacocoDebugReport

6. Locating the JaCoCo Report:

Once executed, the JaCoCo coverage report will be available in the following folder:

${buildDir}/reports/jacoco/jacocoDebugReport/html/index.html Open index.html in a browser to view the coverage details.

Note: mustRunAfter 'connectedDebugAndroidTest' This is used for generate report even if the test case failed.