Best Practices for Writing Cucumber Scenarios: A Beginner’s Guide

BDD (Behavior-Driven Development) emphasizes communication gap between developers, testers and business stakeholders through the use of a common language to describe the behavior of a system.It focuses on writing tests in a human-readable format, typically using a “given-when-then” structure which helps clarify requirements and expectations.One of the most popular tools for implementing BDD is Cucumber.

What is Behavior-Driven Development (BDD)?

BDD is a collaborative approach to software development that emphasizes:

• Understanding : Involves all stakeholders – developers, testers and business analysts.
• Scenarios : Defines system behavior in plain english language, ensuring clarity for everyone.
• Executable Specifications : Converts those plain-language scenarios into automated tests.

What is Cucumber?

Cucumber is a tool that supports BDD by :

• Allowing you to write test cases in plain language (like English).
• Using the Gherkin language to describe behaviors.
• Connecting these test cases to actual code for automated execution.
• Cucumber integrates with programming languages like Java, JavaScript,Python etc.

Setting Up Cucumber :

Prerequisites :

•  A programming language of our choice (eg. Java).
•  A testing framework like JUnit or TestNG for Java.
•  A development environment (eg Eclipse).

Install Cucumber Dependencies :

For a Java project, include the following dependencies in your pom.xml if you’re using Maven :

<dependency>
    <groupId>io.cucumber</groupId>
    <artifactId>cucumber-java</artifactId>
    <version>7.14.0</version>
</dependency>
<dependency>
    <groupId>io.cucumber</groupId>
    <artifactId>cucumber-junit</artifactId>
    <version>7.14.0</version>
</dependency>

How to write Test Case using Cucumber :

Step 1 : Write a Feature File
Feature files describe all scenarios along with steps in gherkin language(simple language)  which is human-readable and easy to write.Its extension is .feature.
Example : login.feature

Feature: User Login
 Scenario: Successful Login
   Given the user is on the login page
   When the user enters valid credentials (username:"[email protected]",password:"test@123")
   Then the user should be redirected to the dashboard

Step 2 : Define Step Definitions
For Each step in the feature file there are corresponding java methods we have to create in step definition file. Its extension is .java

import io.cucumber.java.en.*;
public class LoginSteps {
    @Given("the user is on the login page")
    public void userIsOnLoginPage() {
        System.out.println("User navigates to login page");
    }
    @When("the user enters valid credentials")
    public void userEntersValidCredentials(String user, String pwd) {
        System.out.println("User enters username and password");
    }
    @Then("the user should be redirected to the dashboard")
    public void userRedirectedToDashboard() {
        System.out.println("User is redirected to the dashboard");
    }
}

 Step 3 : Create a Test Runner
It is basically a junit file.Cucumber internally follows the junit file.The test runner integrates Cucumber with your test framework (eg. JUnit).

import org.junit.runner.RunWith;
import io.cucumber.junit.Cucumber;
import io.cucumber.junit.CucumberOptions;
@RunWith(Cucumber.class)
@CucumberOptions(
    features = "src/test/resources/features",
    glue = "stepDefinitions"
)
public class TestRunner {}

  Step 4 : Run Test

•  Execute the TestRunner class as a JUnit test.
• Watch Cucumber execute the steps and display results in the console.

Advantages of Cucumber :

• Plain Language : Scenarios are easy for non-technical stakeholders to read and understand.
• Collaboration : Improves communication between technical and non-technical teams.
• Reusability : Step definitions can be reused across scenarios.
• Automation : Integrates with Selenium, Appium and other tools for UI and API testing.

Conclusion :

Cucumber makes it easier for teams to use Behavior-Driven Development by improving collaboration and simplifying automated testing. It helps our team stay aligned with user expectations, produce quality code, and deliver great software. Here are a few ways Cucumber can support the team.

• Cucumber bridges the gap between collaboration and automation in Behavior-Driven Development.
• Cucumber makes Behavior-Driven Development effortless with enhanced collaboration and accessible automation.
• Here are a few ways Cucumber helps teams :