Cucumber for java

Cucumber for Java: A Beginner's Guide

![Cucumber Logo](

Introduction

Cucumber is a popular open-source testing framework used for Behavior Driven Development (BDD). It allows you to write tests in a more human-readable format and encourages collaboration between developers, testers, and business stakeholders. In this article, we will explore how to use Cucumber for Java.

Setting up Cucumber for Java

To get started with Cucumber for Java, you need to set up the necessary dependencies in your project. You will need the following dependencies in your pom.xml file for Maven projects:

<dependencies>
    <dependency>
        <groupId>io.cucumber</groupId>
        <artifactId>cucumber-java</artifactId>
        <version>6.11.0</version>
        <scope>test</scope>
    </dependency>
    <dependency>
        <groupId>io.cucumber</groupId>
        <artifactId>cucumber-junit</artifactId>
        <version>6.11.0</version>
        <scope>test</scope>
    </dependency>
</dependencies>

Once you have added the dependencies, you can create a new directory src/test/resources and create a new file with the extension .feature. This file will contain your Cucumber scenarios written in Gherkin syntax.

Writing Cucumber Scenarios

Cucumber scenarios are written in a human-readable format called Gherkin syntax. Each scenario consists of steps written as Given, When, and Then statements. Let's consider a simple example of a calculator application:

Feature: Calculator
Scenario: Addition
    Given I have entered 50 into the calculator
    And I have entered 70 into the calculator
    When I press add
    Then the result should be 120 on the screen

In the above scenario, we have defined the steps for adding two numbers in a calculator. Now, let's create a step definition file to implement these steps.

Implementing Step Definitions

Step definitions are the actual code that gets executed when Cucumber encounters a step in a scenario. Create a new Java class and annotate it with @CucumberOptions and @RunWith annotations. Here's an example:

import org.junit.runner.RunWith;
import io.cucumber.junit.Cucumber;
import io.cucumber.junit.CucumberOptions;

@RunWith(Cucumber.class)
@CucumberOptions(features = "src/test/resources", glue = "stepdefinitions")
public class CalculatorTest {
}

In the above code, we have specified the location of feature files (src/test/resources) and the package where step definitions are located (stepdefinitions).

Now, let's implement the step definitions for our calculator scenario:

import io.cucumber.java.en.Given;
import io.cucumber.java.en.Then;
import io.cucumber.java.en.When;
import org.junit.Assert;

public class CalculatorSteps {
    private int result;
    private Calculator calculator;

    @Given("I have entered {int} into the calculator")
    public void i_have_entered_into_the_calculator(Integer number) {
        calculator = new Calculator();
        calculator.enterNumber(number);
    }

    @When("I press add")
    public void i_press_add() {
        result = calculator.add();
    }

    @Then("the result should be {int} on the screen")
    public void the_result_should_be_on_the_screen(Integer expectedResult) {
        Assert.assertEquals(expectedResult.intValue(), result);
    }
}

In the above code, we have defined step definitions using annotations such as @Given, @When, and @Then. These annotations map the steps defined in the feature file to the corresponding method in the step definition class.

Running Cucumber Tests

To run the Cucumber tests, you can simply right-click on your test class and select "Run as JUnit Test" in your IDE. This will execute the feature files and display the test results.

Conclusion

In this article, we have explored how to set up Cucumber for Java and write Cucumber scenarios using Gherkin syntax. We have also seen how to implement step definitions and execute the Cucumber tests. Cucumber provides a powerful tool for collaboration between developers, testers, and business stakeholders, making it easier to understand and validate the application's behavior.

Cucumber helps in creating a common language that bridges the gap between technical and non-technical team members. It encourages collaboration and helps in ensuring that the application meets the business requirements.

So, if you want to write more readable and collaborative tests in Java, give Cucumber a try!

Sequence Diagram

sequenceDiagram
    participant User
    participant Calculator
    User->>Calculator: Enter numbers (50, 70)
    User->>Calculator: Press add
    Calculator->>Calculator: Add numbers
    Calculator->>User: Display result (120)

Pie Chart

pie
    title Test Results
    "Passed" : 80
    "Failed" : 20

Remember, Cucumber for Java is just one of the many options available for BDD testing. It's important to choose the right tool based on your project requirements and team preferences. Happy testing!