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 "user@test.com" 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 "wrong@test.com" 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 |
| admin@test.com | admin123 | Dashboard |
| user@test.com | password | Dashboard |
| bad@test.com | 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 |