Android Instrumented unit test on project library

Question

I inherited an Android Project composed by the main app and a Library . My goal is to test the whole project, so I started from the Library : first i use JUnit to test some classes/method, writing my test undeer app/src/test/java (unit test) of my Library project, also generating a code coverage report by Android Studio. The problem comes when i find a Class that uses Parcel (from Android Framework), so this time I had to setup an instrumented test (app/src/androidTest/java), also within the Library project.

When I try run the instrumented test, plugging an Android device, i got this message:

Started running tests
Test running failed: Instrumentation run failed due to 'java.lang.ClassNotFoundException'
Empty test suite.

I don't understand why "Empty test suite" while there're several @Test methods in my test class. Have I to setup Gradle how to link main app and library during test o maybe I have to move all my test in the main app?!

This is my gradle for Library module:

apply plugin: 'com.android.library'


    android {

        compileSdkVersion rootProject.ext.compileSdkVersion
        buildToolsVersion rootProject.ext.buildToolsVersion

        defaultConfig {
            minSdkVersion rootProject.ext.minSdkVersion
            // Added for instrumental tests
            testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"

            javaCompileOptions {
                annotationProcessorOptions {
                    arguments = ["room.schemaLocation": "$projectDir/schemas".toString()]
                }
            }
        }

        buildTypes {
            release {
                minifyEnabled true
                proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
            }
            debug {
                debuggable true
                testCoverageEnabled true
            }
        }

        compileOptions {
            sourceCompatibility JavaVersion.VERSION_1_8
            targetCompatibility JavaVersion.VERSION_1_8
        }

        testOptions {
            unitTests.returnDefaultValues = true
        }

    }

    dependencies {

        implementation "com.android.support:support-v4:$rootProject.supportLibraryVersion"
        implementation "com.google.code.gson:gson:$rootProject.gsonVersion"
        implementation "commons-io:commons-io:$rootProject.commonsioVersion"

        // Dependencies for RxBinding
        implementation 'com.jakewharton.rxbinding2:rxbinding:2.0.0'

        // Dependencies for Rxjava2 and RxAndroid
        implementation 'io.reactivex.rxjava2:rxandroid:2.0.1'
        implementation 'io.reactivex.rxjava2:rxjava:2.1.8'

        // Dependencies for RxBinding
        implementation 'com.jakewharton.rxbinding2:rxbinding:2.0.0'

        // Dependencies for Retrofit
        implementation 'com.squareup.retrofit2:retrofit:2.3.0'
        implementation 'com.squareup.retrofit2:converter-simplexml:2.3.0'
        implementation 'com.jakewharton.retrofit:retrofit2-rxjava2-adapter:1.0.0'
        implementation 'com.squareup.okhttp:okhttp:2.7.0'

        // Dependencies for Room
        // Room (use 1.1.0-alpha1 for latest alpha)
        implementation 'android.arch.persistence.room:runtime:1.1.1'
        implementation 'android.arch.persistence.room:rxjava2:1.1.1'
        annotationProcessor "android.arch.persistence.room:compiler:1.1.1"

        implementation "com.android.support:support-annotations:$rootProject.supportLibraryVersion"
        implementation "org.apache.httpcomponents:httpcore:$rootProject.httpcoreVersion"
        testImplementation 'junit:junit:4.12'

    //    // [Android Instrumented test]
        androidTestImplementation 'junit:junit:4.12'
    //    androidTestImplementation 'androidx.test:runner:1.1.0'
    //    androidTestImplementation 'androidx.test:rules:1.1.0'
    //    // Optional -- Hamcrest library
        androidTestImplementation 'org.hamcrest:hamcrest-library:1.3'
    //    // Optional -- UI testing with Espresso
    //    androidTestImplementation 'androidx.test.espresso:espresso-core:3.1.0'
    //    // Optional -- UI testing with UI Automator
    //    androidTestImplementation 'androidx.test.uiautomator:uiautomator:2.2.0'

        api files('libs/lifesense_ble_v3.3.7.jar')
        api files('libs/MedPixel.jar')

    }

and app's:

apply plugin: 'com.android.application'

android {
    compileSdkVersion 28
    buildToolsVersion '28.0.3'

    defaultConfig {
        applicationId "it.*******.********"
        minSdkVersion rootProject.ext.minSdkVersion
        targetSdkVersion rootProject.ext.targetSdkVersion
        versionCode 2
        versionName "1.0.2"
    }

    buildTypes {
        release {
            shrinkResources true
            minifyEnabled true
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
        debug {
            applicationIdSuffix ".debug"
            debuggable true
        }
    }

    lintOptions {
        checkReleaseBuilds false
    }

    compileOptions {
        sourceCompatibility JavaVersion.VERSION_1_8
        targetCompatibility JavaVersion.VERSION_1_8
    }
}

dependencies {
    implementation project(':..:Libraries:app')
    implementation "com.android.support:support-v4:$rootProject.supportLibraryVersion"
    implementation "com.google.code.gson:gson:$rootProject.gsonVersion"
    implementation "commons-io:commons-io:$rootProject.commonsioVersion"

    // Dependencies for ButterKnife
    implementation 'com.jakewharton:butterknife:8.8.1'
    annotationProcessor 'com.jakewharton:butterknife-compiler:8.8.1'

    // Dependencies for Dagger
    implementation 'com.google.dagger:dagger:2.11'
    annotationProcessor 'com.google.dagger:dagger-compiler:2.11'

    // Dependencies for RxBinding
    implementation 'com.jakewharton.rxbinding2:rxbinding:2.0.0'

    // Dependencies for Rxjava2 and RxAndroid
    implementation 'io.reactivex.rxjava2:rxandroid:2.0.1'
    implementation 'io.reactivex.rxjava2:rxjava:2.1.8'

    // Dependencies for Retrofit
    implementation 'com.squareup.retrofit2:retrofit:2.3.0'
    implementation 'com.squareup.retrofit2:converter-simplexml:2.3.0'
    implementation 'com.jakewharton.retrofit:retrofit2-rxjava2-adapter:1.0.0'
    implementation 'com.squareup.okhttp:okhttp:2.7.0'

    // Dependencies for Room
    implementation 'android.arch.persistence.room:runtime:1.1.1'

    // Dependencies for Roboelecttic
    testImplementation 'org.robolectric:robolectric:3.6.1'
    testImplementation 'junit:junit:4.12'

    // Dependencies for Mockito
    testImplementation 'org.mockito:mockito-core:2.7.22'
    androidTestImplementation 'com.android.support.test:runner:1.0.2'
    androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.2'
    androidTestImplementation 'com.squareup.retrofit2:retrofit-mock:2.0.0'
    androidTestImplementation 'com.squareup.okhttp:mockwebserver:2.7.0'
    androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.2'
    androidTestImplementation 'com.android.support.test:runner:1.0.2'
    androidTestImplementation 'org.mockito:mockito-android:2.7.22'
}

configurations.all {
    resolutionStrategy {
        force "android.arch.core:runtime:1.1.1"
        force "com.android.support:support-core-utils:28.0.0"
        /*force "com.android.support:support-compat:28.0.0"*/
    }
}

Thanks for the attention!

Answer 1

I have run into the same problem, not with Parcel but with other android components like Context .

For this issue,

Empty test suite

Your instrumented test class in must annotated with @RunWith(AndroidJUnit4.class) .

Regarding Code coverage for library

Initially I did write the Instrumented tests in app . But the problem with writing library's InstrumentationTests in app is, you will not get the coverage report for your library .

So, I moved the InstrumentedTests back to library/androidTest folder. After a lot of research, I found a solution to get complete coverage report for library

Do following things in your library's build.gradle file to get coverage

• Add apply plugin: 'jacoco'

• Enable test coverage as below

   android { buildTypes { debug { testCoverageEnabled true } } ... } 

• Add below dependencies

   androidTestImplementation 'com.android.support.test:runner:1.0.2' androidTestImplementation 'com.android.support.test:rules:1.0.2' 

I believe, for any module in your project, If there are androidTests in your module/library, there will be a default task called combinedTestReportDebug .

You can find it in Gradle menu available in vertical bar at Top right corner of Android studio.

Gradle menu > :your-library > Tasks > reporting > combinedTestReportDebug

or

from run this command in your Terminal > ./gradlew clean combinedTestReportDebug -p :your-library

After the tests are completed, you can find coverage or failed tests in following location

For failed tests: your-library/build/reports/androidTests/connected/index.html

For coverage report: your-library/build/reports/coverage/debug/index.html

I hope this helps.

Update:

Sorry, I have forgot to mention the below step which is needed because if not combinedTestReportDebug will not be visible. Thanks to @nicoabie.

In your project's build.gradle file, do the following to make combinedTestReportDebug task visible in your library gradle tasks.

buildscript {
    repositories {
        jcenter()
    }
    dependencies {
        ...
        classpath 'com.vanniktech:gradle-android-junit-jacoco-plugin:0.13.0'
        ...
    }
}
...

apply plugin: 'com.vanniktech.android.junit.jacoco'