Cucumber-Android

This project implements Android support for Cucumber-JVM. It allows running cucumber tests with Android Test Orchestrator and using sharding.

NOTE: Although minSdkVersion for cucumber-android is 14 it requires Java 8 language features and minimum Android API level 26. This is done purposely to allow using cucumber in apps with lower minSdk (to avoid compile errors) but tests should be run on devices with API >= 26. However with desugaring enabled it may work in some configurations on lower API levels assuming that desugaring covers all the Java 8 api. Not all features from cucumber-jvm are supported in cucumber-android due to differences in Android vs JDK (especially junit and html plugins which requires xml factory classes not available in Android)

Developers

Prerequisites

This is ordinary multimodule Android project

• cucumber-android - main library
• cucumber-android-hilt - Hilt object factory
• cucumber-junit-rules-support - internal module for Junit rules support
• cukeulator - sample application with instrumented tests

Building

./gradlew assemble

Setting up the dependency

The first step is to include cucumber-android into your project, for example, as a Gradle androidTestImplementation dependency:

androidTestImplementation "io.cucumber:cucumber-android:$cucumberVersion"

Using Cucumber-Android

1. Create a class in your testApplicationId package (usually it's a namespace from build.gradle with .test suffix) and add @CucumberOptions annotation to that class. You can also put such class in different package or have many such classes in different packages but then you have to provide path to it in instrumentation argument optionsAnnotationPackage.

Gradle example:

android {
    defaultConfig {
        testInstrumentationRunner "io.cucumber.android.runner.CucumberAndroidJUnitRunner"
        testInstrumentationRunnerArguments(optionsAnnotationPackage: "some.other.package")
    }
}

Commandline example:

adb shell am instrument -w -e optionsAnnotationPackage some.other.package com.mycompany.app.test/com.mycompany.app.test.MyTests

This class doesn't need to have anything in it, but you can also put some codes in it if you want. The purpose of doing this is to provide cucumber options. A simple example can be found in cukeulator. Or a more complicated example here:

package com.mycompany.app.test;

@CucumberOptions(glue = { "com.mytest.steps" }, tags = "~@wip" , features = { "features" })
public class MyTests 
{
}

glue is the list of packages which contain step definitions classes and also classes annotated with @WithJunitRule, tags is the tags placed above scenarios titles you want cucumber-android to run or not run, features is the path to the feature files in android test assets directory.

2. Write your .feature files under your project's android test assets/<features-folder> folder. If you specify features = "features" in @CucumberOptions like the example above then it's androidTest/assets/features (might be also androidTest<Flavor/BuildType>/assets/features).

3. Write your step definitions under the package name specified in glue. For example, if you specified glue = ["com.mytest.steps"], then create a new package under your androidTest/java (or androidTest/kotlin) named com.mytest.steps and put your step definitions under it. Note that all subpackages will also be included, so you can also put in com.mytest.steps.mycomponent.

4. Set instrumentation runner to io.cucumber.android.runner.CucumberAndroidJUnitRunner or class that extends it

android.defaultConfig.testInstrumentationRunner "io.cucumber.android.runner.CucumberAndroidJUnitRunner"

If needed you can specify some cucumber options using instrumentation arguments. Check available options in io.cucumber.android.CucumberAndroidJUnitArguments.PublicArgs class

For example to specify glue package use:

android.defaultConfig.testInstrumentationRunnerArguments(glue: "com.mytest.steps")

Debugging

Please read the Android documentation on debugging.

Examples

Currently there is one example in subproject cukeulator

To create a virtual device and start an Android emulator:

$ANDROID_HOME/tools/android avd

Junit rules support

Experimental support for Junit rules was added in version 4.9.0. Cucumber works differently than junit - you cannot just add rule to some steps class because during scenario execution many such steps classes can be instantiated. Cucumber has its own Before/After mechanism. If you have just 1 steps class then this could work If you have many steps classes then it is better to separate rule and @Before/@After hooks from steps classes

To let Cucumber discover that particular class has rules add

@WithJunitRule
class ClassWithRules {
    ...
}

and put this class in glue package. Glue packages are specified in @CucumberOptions annotation, see Using Cucumber-Android

You can specify tag expression like @WithJunitRule("@MyTag") to control for which scenarios this rule should be executed. See compose.feature and ComposeRuleHolder for example

Sharding and running with Android Test Orchestrator

CucumberAndroidJUnitRunner works with Android Test Orchestrator and sharding because it reports tests and classes as feature names and scenario names like My feature#My scenario and is able to parse -e class argument from instrumentation. It also supports multiple names in -e class argument separated by comma. This means that feature and scenario name cannot have comma in it's name because it is reserved for separating multiple names (only if you want to use Orchestrator or in general class argument, for other use cases comma is allowed).

Jetpack Compose rule

@WithJunitRule
class ComposeRuleHolder {

    @get:Rule
    val composeRule = createEmptyComposeRule()
}

then inject this object in steps, e.g. (can be also inject as lateinit var field (depending on injection framework used)

class KotlinSteps(val composeRuleHolder: ComposeRuleHolder, val scenarioHolder: ActivityScenarioHolder):SemanticsNodeInteractionsProvider by composeRuleHolder.composeRule {

    ...
    
    @Then("^\"([^\"]*)\" text is presented$")
    fun textIsPresented(arg0: String) {
        onNodeWithText(arg0).assertIsDisplayed()
    }
}

Check Junit rules support for more information of adding classes with JUnit rules

Hilt

There are 2 solutions for using Hilt with Cucumber:

1. HiltObjectFactory

Add dependency:

androidTestImplementation "io.cucumber:cucumber-android-hilt:$cucumberVersion"

Don't use any other dependency with ObjectFactory like cucumber-picocontainer

HiltObjectFactory will be automatically used as ObjectFactory.

To inject object managed by Hilt into steps or hook or any other class managed by Cucumber:

@HiltAndroidTest
class KotlinSteps(
    val composeRuleHolder: ComposeRuleHolder,
    val scenarioHolder: ActivityScenarioHolder
):SemanticsNodeInteractionsProvider by composeRuleHolder.composeRule {

    @Inject
    lateinit var greetingService:GreetingService

    @Then("I should see {string} on the display")
    fun I_should_see_s_on_the_display(s: String?) {
       Espresso.onView(withId(R.id.txt_calc_display)).check(ViewAssertions.matches(ViewMatchers.withText(s)))
    }

}

Such class:

• must have @HiltAndroidTest annotation to let Hilt generate injecting code
• can have Cucumber managed objects like hooks injected in constructor
• can have Cucumber managed objects injected in fields but such objects have to be annotated with @Singleton annotation and constructor has to be annotated with @Inject annotation
• can have Hilt managed objects injected using field injection or constructor
• can have objects injected in base class

Also: after each scenario Hilt will clear all objects and create new ones (even these marked as @Singleton) (like it does for each test class in Junit)

2. @WithJunitRule

Hilt requires to have rule in actual test class (which for cucumber is impossible because there is no such class). To workaround that:

See https://developer.android.com/training/dependency-injection/hilt-testing#multiple-testrules how to use hilt with other rules (like compose rule)

@WithJunitRule(useAsTestClassInDescription = true)
@HiltAndroidTest
class HiltRuleHolder {

    @Rule(order = 0) 
    @JvmField
    val hiltRule = HiltAndroidRule(this)

   //if you need it to be injected   
    @Inject
    lateinit var greetingService: GreetingService

    @Before
    fun init() {
        //if you have anything to inject here and/or used elsewhere in tests    
        hiltRule.inject()
    }

}

then you can inject such class to steps class using Cucumber dependency injector (like picocontainer)

Running scenarios from IDE

There is third-party plugin (not related with Cucumber organisation and this repository) which allows running scenarios directly from Android Studio or Intellij

Cucumber for Kotlin and Android

Troubleshooting

1. Compose tests fails

java.lang.IllegalStateException: Test not setup properly. Use a ComposeTestRule in your test to be able to interact with composables

Solution

Check Jetpack Compose rule section. Make sure that your class with @WithJunitRule annotation is placed in glue package as described in Using Cucumber-Android