Experimental Gradle plugin for PIT Mutation Testing in Android projects

This is a fork of gradle-pitest-plugin which supports Android gradle projects.

Applying plugin in build.gradle

With Gradle plugin portal

plugins {
  id 'pl.droidsonroids.pitest' version '0.2.20'
}

plugins {
  id("pl.droidsonroids.pitest") version "0.2.20"
}

With Maven central repository

buildscript {
  repositories {
    mavenCentral()
    google()
  }
  dependencies {
    classpath("pl.droidsonroids.gradle:gradle-pitest-plugin:0.2.20")
  }
}

plugins {
  id("com.android.application")
  //or id("com.android.library")
  //or id("com.android.test")
  id("pl.droidsonroids.pitest")
}

Usage

pitest<variant> tasks will be created for each build variant (eg. pitestProDebug for pro product flavor and debug build type). Additionally pitest task will run tasks for all variants.

After the measurements a report created by PIT will be placed in ${PROJECT_DIR}/build/reports/pitest/<variant> directory.

For more information see README of source project

Robolectric and UnMock

This plugin by default adds mockable Android JAR (generated by Android Gradle Plugin) to classpath used under pitest tests.

If you are using alternative Android framework in tests, like Robolectric or UnMock Gradle Plugin, you may want to add excludeMockableAndroidJar to pitest configuration eg:

pitest {
    targetClasses = ['com.myapp.*']
    excludeMockableAndroidJar = true
}

In such case default mockable Android JAR won't be added and alternative one will be used under tests.

Using jetifier

This plugin tries to discover all the unit test dependencies and add them to the pitest classpath automatically. But, this feature doesn't work with jetifier (android.enableJetifier=true in gradle.properties).

If you are using jetifier and encounter NoClassDefFoundErrors in tests run under pitest, you may want to add some dependencies manually to the pitestTestCompile configuration. For example:

buildscript {
    configurations.create("pitestTestCompile")
    dependencies {
        pitestTestCompile 'io.mockk:mockk-agent-jvm:1.11.0'
    }
}

Troubleshooting

Tests fail when run under pitest but pass without it

Issue occurs when using Android API without mocking it. Pitest verbose logs may list exceptions like ExceptionInitializerError.

The fastest solution is to set android.testOptions.unitTests.returnDefaultValues = true. See Local unit testing documentation to see other consequences of this change.