How to use android.test.mock in Android Studio

Question

I'm trying to use MockContext in unit tests for Android project in android Studio. The problem is, package android.test.* is not visible in the project.

I'm not sure what should I add to Gradle in order to import it. I tried com.android.support.test:rules:1.0.2 and androidx.test:rules:1.1.1 (one of the suggestions made by IDE), but that's not the one I'm looking for.

build.gradle:

apply plugin: 'com.android.application'

android {
    compileSdkVersion 28
    defaultConfig {
        applicationId "com.myApp"
        minSdkVersion 23
        targetSdkVersion 28
        versionCode 1
        versionName "1.0"
        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
        }
    }
}

dependencies {
    implementation fileTree(dir: 'libs', include: ['*.jar'])
    //noinspection GradleCompatible
    implementation 'com.android.support:appcompat-v7:28.0.0'
    implementation 'com.android.support:design:28.0.0'
    implementation 'com.android.support.constraint:constraint-layout:1.1.3'
    testImplementation 'junit:junit:4.12'
    androidTestImplementation 'com.android.support.test:runner:1.0.2'
    androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.2'
    implementation 'com.google.firebase:firebase-core:16.0.8'
    implementation 'com.android.support:recyclerview-v7:28.0.0'
    testImplementation 'com.android.support.test:rules:1.0.2'
}

apply plugin: 'com.google.gms.google-services'

Error message when compiling:

error: package android.test.mock does not exist

What should I add to gradle to have access to android.test package?

Answer 1

Actually, you can access android.test.mock from your unit tests and gain access to the MockContext class. For AndroidX projects, you can add the following in your app module's build.gradle:

android {
    ...
    useLibrary 'android.test.mock'
}

Source: https://developer.android.com/training/testing/set-up-project

Answer 2

That class is a framework class, not from a library. You can tell by the package name: anything in android. (instead of com.android. or androidx.) is a framework class. Hence, you could only use that for instrumented tests, not unit tests.

You can either create custom mocks (e.g., with Mockito) or use Robolectric, depending on what you're trying to do.