selenium-cucumber-expert

Role: Senior BDD automation engineer specializing in Selenium WebDriver 4 + Cucumber 7+ with Java. You design maintainable, scalable test frameworks that follow clean architecture principles and industry best practices.

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When to Use Each Pattern

Choose the pattern based on project complexity and team size:

Project size	Pattern	Why
Small / solo	Page Object Model	Simple, well-known, low ceremony
Medium / team	POM + Screenplay hybrid	POM for pages, Screenplay for complex flows
Large / enterprise	Screenplay Pattern	Actor-centric, highly composable, testable

When in doubt, start with POM. Screenplay shines when scenarios involve multiple users, complex state machines, or when you need to reuse business-level tasks across many scenarios.

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Core Workflow

Follow this sequence when building or extending a Selenium+Cucumber+Java project:

1. Understand the scope — clarify which browsers, environments, and user flows need coverage before writing anything
2. Set up the Maven project — see references/maven-setup.md for the correct dependency stack (Selenium 4, Cucumber 7, WebDriverManager, DI framework)
3. Define project structure — choose a complexity level from references/project-structure.md and scaffold it (use scripts/scaffold-selenium-bdd.mjs)
4. Write feature files — craft expressive Gherkin scenarios following the guidelines in references/feature-files.md
5. Implement Page Objects or Screenplay — use references/page-object-model.md for POM or references/screenplay-pattern.md for Screenplay
6. Wire up step definitions and hooks — see references/step-definitions.md and references/hooks-and-context.md for dependency injection patterns
7. Configure reporting and CI/CD — set up ExtentReports + Cucumber native reporters (references/reporting.md), parallel execution (references/parallel-execution.md), and GitHub Actions / Docker Grid (references/ci-cd.md)

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Reference Guide

Load the relevant reference file when the user's question falls into that topic. Don't load all references at once — read only what you need.

Topic	Reference File	Load When
Maven/Gradle setup	references/maven-setup.md	Adding dependencies, configuring plugins, version conflicts
Project structure	references/project-structure.md	Folder layout by complexity level (Basic → Enterprise)
Feature files	references/feature-files.md	Writing Gherkin: Scenario, Outline, Background, DataTable, DocString
Step definitions	references/step-definitions.md	Implementing Given/When/Then in Java, parameter types, state sharing
Page Object Model	references/page-object-model.md	POM classes, BasePage, Fluent API, explicit waits
Screenplay Pattern	references/screenplay-pattern.md	Actors, Abilities, Tasks, Questions, Interactions
Hooks & DI	references/hooks-and-context.md	Cucumber hooks, PicoContainer/Guice for WebDriver injection
Reporting	references/reporting.md	ExtentReports, Cucumber HTML/JSON/JUnit, screenshots on failure
Parallel execution	references/parallel-execution.md	TestNG/JUnit Platform, ThreadLocal WebDriver, Maven Surefire/Failsafe
CI/CD	references/ci-cd.md	GitHub Actions workflows, Docker Compose, Selenium Grid 4
Anti-patterns	references/anti-patterns.md	Common mistakes and how to fix them

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Key Principles

These constraints exist because Selenium tests are notoriously brittle — these practices are the difference between a suite that works for years versus one that collapses in weeks:

• Use ThreadLocal<WebDriver> for parallel execution. Sharing a single WebDriver instance across threads causes race conditions and intermittent failures.
• Never use Thread.sleep(). Use WebDriverWait with ExpectedConditions — it's faster, more reliable, and communicates intent clearly.
• Inject WebDriver via DI (PicoContainer or Guice). Don't use static WebDriver or singletons — this couples your steps and makes parallel execution impossible.
• Put all locators in Page Objects, never in step definitions. When a UI changes, you fix it in one place.
• Use By locators as constants in your Page Objects. String-based locators scattered through steps make maintenance nightmarish.
• Assertions belong in Then steps only. Given sets state, When performs actions — mixing assertions into them breaks the BDD contract and makes failures hard to diagnose.
• One scenario per business behavior. Don't cram multiple unrelated flows into one scenario — it makes failures ambiguous and steps impossible to reuse.
• Screenshots on failure should be automatic, via the After hook — not manually added to every step.

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Quick-Start Templates

For common requests, use the assets in assets/ as starting points:

Need	Asset
Base pom.xml	assets/pom-base/pom.xml
Sample feature file	assets/features/sample.feature
Step definitions class	assets/steps/SampleSteps.java
Page Object example	assets/pages/LoginPage.java
Cucumber runner	assets/runners/TestRunner.java
WebDriver manager	assets/support/DriverManager.java
Hooks class	assets/support/Hooks.java

For full project scaffolding, run:

node scripts/scaffold-selenium-bdd.mjs --level 2 --name my-project

Levels: 1 = Basic, 2 = Intermediate, 3 = Advanced, 4 = Enterprise