Have you learned how to implement behavior-driven development in Android using Cucumber?

Behavior-driven development (BDD) bridges the gap between technical and non-technical people in software development by using human language.

Translated from Implement Behavior-Driven Development in Android With Cucumber, author Stephen Henry.

Software development involves processes and people. People include both technical and non-technical stakeholders, but since the process is mostly technical, it creates a large gap between technical and non-technical stakeholders.

Bridging this gap requires a collaborative approach that uses natural language to encourage communication and collaboration between technical and non-technical stakeholders. This is exactly the goal of Behavior Driven Development (BDD): to achieve understanding between developers, testers, and business stakeholders.

As a software engineer, I have been using one of the most popular tools, Cucumber, to implement BDD. Cucumber helps business and technical teams collaborate by executing specifications collaboratively. BDD specifications also double as automated tests. Using the Gherkin framework, these specifications are written collaboratively, keeping the team aligned with the living documentation of the system.

In this article, I'll explain five simple steps to integrate Cucumber tests into your Android application.

• There is the Java Virtual Machine (JVM) language.
• It integrates seamlessly with the Espresso framework for user interface (UI) testing.
• It enables anyone to write plain text descriptions of desired behavior in any spoken language and run automated tests using these descriptions. Its plain language parser, Gherkin, facilitates this because it specifies expected software behavior in a clear and logical language that can be understood by customers, stakeholders, managers, developers, quality assurance (QA) testers, etc.
• It provides excellent documentation about the application.
• It can run automated acceptance tests using BDD.

Setting up Android Studio for testing with Cucumber

Let's take a deeper look at how to set up Android Studio with Cucumber Tests.

Prerequisites

Before you begin, make sure you have the Android Studio integrated development environment (IDE) installed.

You may also consider installing the following plugins from the Android Studio Marketplace:

• Cucumber support for Kotlin and Android: This plugin provided by Finanteq makes it possible to write step definitions in Kotlin to support Cucumber. It allows running Cucumber scenarios as Android instrumented tests directly from the IDE.
• JetBrains' Gherkin and Cucumber support for Java: These plugins add support for the Gherkin language used by the Cucumber testing tool and provide coding assistance for step definitions.

1. Create an Android Studio project with dependencies

Create a new Android Studio project in the IDE, or use an existing project. Next, add the Cucumber dependency.

In the build.gradle file of the app-level module, add the following dependency:

 androidTestImplementation("io.cucumber:cucumber-android:7.14.0") androidTestImplementation ("androidx.test:rules:1.6.1")

2. Create your Instrumentation Runner

In app/src/androidTest/java/com/your/app/, create a custom Instrumentation Runner called CucumberTestInstrumentation.java. Add this class to build.gradle under android > defaultConfig:

 defaultConfig { ..... testInstrumentationRunner "com.your.app.CucumberTestInstrumentation" }

You have successfully set up Android Studio for Cucumber, so now you can move on to the exciting part.

3. Given, When, And and Then

Gherkin is a domain-specific language that describes the implementation of functionality step by step using non-technical terms. It uses the keywords Given, When, And, and Then to explain the steps. The steps can be written in any human language, such as English, Arabic, or Luo.

Here is an example of a Gherkin feature scenario written in English that I will use in this project:

 Feature: Ability of the customer to login Scenario Outline: Where the customer requests to log in Given the login screen is displayed to the customer When the customer enters email "<email>" And the customer enters password "<password>" And the customer requests to log in Then the login status will be "<status>" Examples: | email | password | status | | [email protected] | qwerty1234 | Login Failed | | [email protected] | somePass02 | Login Failed | | [email protected] | sayNerd001 | Login Success |

Create an assets directory in app/src/androidTest/assets and add a folder called features. You will add feature files containing the above step definitions written in English.

Add a new .feature file called login.feature and add the above functionality steps.

4. Use Espresso framework to implement scenario steps

In app/src/androidTest/java/com/your/app/, create a Kotlin class called LoginSteps. This is where you will write tests that implement the steps in login.feature.

Here are the code snippets for the steps implementation:

 @Given("^the login screen is displayed to the customer$") fun theLoginScreenIsDisplayedToTheCustomer() { composeTestRule.setContent { LoginScreen() } composeTestRule.onNodeWithTag(LOGIN_SCREEN).assertIsDisplayed() composeTestRule.onNodeWithTag(LOGIN_SCREEN_EMAIL).assertIsDisplayed() composeTestRule.onNodeWithTag(LOGIN_SCREEN_PASSWORD).assertIsDisplayed() composeTestRule.onNodeWithTag(LOGIN_SCREEN_BUTTON).assertIsDisplayed() composeTestRule.mainClock.advanceTimeBy(500) } @When("^the customer enters email \"([^\"]*)\"$") fun theCustomerEntersEmail(email: String) { composeTestRule.onNodeWithTag(LOGIN_SCREEN_EMAIL).performTextInput(email) composeTestRule.mainClock.advanceTimeBy(500) composeTestRule.onNodeWithTag(LOGIN_SCREEN_EMAIL).assertExists().assert(hasText(email)) }

5. Provide Cucumber options

When running the tests you have to provide the package containing the step definitions and paste them into the steps.

In app/src/androidTest/java/com/your/app, create a folder called test and add a new Kotlin class.

 @RunWith(Cucumber::class) @CucumberOptions( features = ["src/androidTest/assets/features/login.feature"], glue = ["com.stevehechio.apps.hechiobdd.LoginSteps"], monochrome = true ) class HechioCucumberTestRunner

Finally, you can run the tests, but first, confirm that your project structure looks like this:

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Running Tests

To run the tests:

• Open Edit Configuration.
• Click + on the left panel and select Android Instrumented Tests.
• Write the name to match the name of the feature so it's easier to remember. In this case, it's the ability for customers to log in. Then click Run or OK to run or debug it later from the IDE toolbar.

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Following is the result of the above implementation.

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in conclusion

Bridging the gap between technical and non-technical stakeholders is critical to effective software development. Behavior-driven development promotes collaboration and communication in natural language.

Tools such as Cucumber help implement BDD using executable specifications as automated tests, enabling teams to create clear, shared documentation. Integrating Cucumber into your Android app development can enhance team coordination and streamline development.