Cucumber Skill

# Cucumber BDD Skill

## Core Patterns

### Feature File (Gherkin)

```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

```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

```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

```java
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

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

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

```bash
# 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:**
```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:**
```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 |