Cucumber BDD Skill

Core Patterns

Feature File (Gherkin)

Feature: User Login
  As a registered user
  I want to log into the application
  So that I can access my dashboard

  Background:
    Given I am on the login page

  Scenario: Successful login
    When I enter "[email protected]" in the email field
    And I enter "password123" in the password field
    And I click the login button
    Then I should be redirected to the dashboard
    And I should see "Welcome" on the page

  Scenario: Invalid credentials
    When I enter "[email protected]" in the email field
    And I enter "wrongpass" in the password field
    And I click the login button
    Then I should see an error message "Invalid credentials"

  Scenario Outline: Login with various users
    When I enter "<email>" in the email field
    And I enter "<password>" in the password field
    And I click the login button
    Then I should see "<result>"

    Examples:
      | email           | password    | result     |
      | [email protected]  | admin123    | Dashboard  |
      | [email protected]   | password    | Dashboard  |
      | [email protected]    | wrong       | Error      |

Step Definitions — Java

import io.cucumber.java.en.*;
import static org.junit.jupiter.api.Assertions.*;

public class LoginSteps {
    private LoginPage loginPage;
    private DashboardPage dashboardPage;

    @Given("I am on the login page")
    public void iAmOnTheLoginPage() {
        loginPage = new LoginPage(driver);
        loginPage.navigate();
    }

    @When("I enter {string} in the email field")
    public void iEnterEmail(String email) {
        loginPage.enterEmail(email);
    }

    @When("I enter {string} in the password field")
    public void iEnterPassword(String password) {
        loginPage.enterPassword(password);
    }

    @When("I click the login button")
    public void iClickLogin() {
        dashboardPage = loginPage.clickLogin();
    }

    @Then("I should be redirected to the dashboard")
    public void iShouldBeOnDashboard() {
        assertTrue(driver.getCurrentUrl().contains("/dashboard"));
    }

    @Then("I should see {string} on the page")
    public void iShouldSeeText(String text) {
        assertTrue(dashboardPage.getPageSource().contains(text));
    }
}

Step Definitions — JavaScript

const { Given, When, Then } = require('@cucumber/cucumber');
const { expect } = require('chai');

Given('I am on the login page', async function() {
  await this.page.goto('/login');
});

When('I enter {string} in the email field', async function(email) {
  await this.page.fill('#email', email);
});

When('I click the login button', async function() {
  await this.page.click('button[type="submit"]');
});

Then('I should see {string} on the page', async function(text) {
  const content = await this.page.textContent('body');
  expect(content).to.include(text);
});

Hooks

import io.cucumber.java.*;

public class Hooks {
    @Before
    public void setUp(Scenario scenario) {
        driver = new ChromeDriver();
    }

    @After
    public void tearDown(Scenario scenario) {
        if (scenario.isFailed()) {
            byte[] screenshot = ((TakesScreenshot) driver).getScreenshotAs(OutputType.BYTES);
            scenario.attach(screenshot, "image/png", "failure-screenshot");
        }
        driver.quit();
    }
}

Tags

@smoke
Feature: Login
  @critical @fast
  Scenario: Quick login
    ...

  @slow @regression
  Scenario: Full login flow
    ...

# Run by tag
mvn test -Dcucumber.filter.tags="@smoke"
mvn test -Dcucumber.filter.tags="@smoke and not @slow"

Anti-Patterns

Bad	Good	Why
UI details in Gherkin	Business language	Readability
One step per line of code	Meaningful business steps	Abstraction
No Background for shared steps	Use Background	DRY
Imperative steps	Declarative steps	Maintainable

Cloud Execution on TestMu AI

Set environment variables: LT_USERNAME, LT_ACCESS_KEY

Java:

// CucumberHooks.java
ChromeOptions browserOptions = new ChromeOptions();
HashMap<String, Object> ltOptions = new HashMap<>();
ltOptions.put("user", System.getenv("LT_USERNAME"));
ltOptions.put("accessKey", System.getenv("LT_ACCESS_KEY"));
ltOptions.put("build", "Cucumber Build");
ltOptions.put("name", scenario.getName());
ltOptions.put("platformName", "Windows 11");
ltOptions.put("video", true);
browserOptions.setCapability("LT:Options", ltOptions);
driver = new RemoteWebDriver(new URL("https://hub.lambdatest.com/wd/hub"), browserOptions);

JavaScript:

const driver = new Builder()
  .usingServer(`https://${process.env.LT_USERNAME}:${process.env.LT_ACCESS_KEY}@hub.lambdatest.com/wd/hub`)
  .withCapabilities({ browserName: 'chrome', 'LT:Options': {
    user: process.env.LT_USERNAME, accessKey: process.env.LT_ACCESS_KEY,
    build: 'Cucumber Build', platformName: 'Windows 11', video: true
  }}).build();

Quick Reference

Task	Command
Run all (Java)	mvn test with cucumber-junit-platform-engine
Run all (JS)	npx cucumber-js
Run tagged	--tags "@smoke"
Dry run	--dry-run
Generate snippets	Run undefined steps

Deep Patterns → reference/playbook.md

§	Section	Lines
1	Project Setup & Configuration	Maven, runner, rerun
2	Feature Writing Patterns	Background, outlines, DataTable
3	Step Definitions	Typed steps, DI injection
4	Dependency Injection & Shared State	PicoContainer, ScenarioContext
5	Hooks (Lifecycle Management)	Before/After ordering, screenshots
6	Custom Parameter Types	Transformers, DocString
7	Parallel Execution	Thread-safe, TestNG parallel
8	Reporting	Allure, masterthought, JSON
9	CI/CD Integration	GitHub Actions, tag matrix
10	Debugging Quick-Reference	10 common problems
11	Best Practices Checklist	13 items