docs: federate scattered markdown files into centralized docs (#36756)

Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>

docs/developer_portal/testing/e2e-testing.md

@@ -24,57 +24,204 @@ under the License.
 
 # End-to-End Testing
 
-🚧 **Coming Soon** 🚧
+Apache Superset uses Playwright for end-to-end testing, migrating from the legacy Cypress tests.
 
-Guide for writing and running end-to-end tests using Playwright and Cypress.
-
-## Topics to be covered:
+## Running Tests
 
 ### Playwright (Recommended)
-- Setting up Playwright environment
-- Writing reliable E2E tests
-- Page Object Model pattern
-- Handling async operations
-- Cross-browser testing
-- Visual regression testing
-- Debugging with Playwright Inspector
-- CI/CD integration
 
-### Cypress (Deprecated)
-- Legacy Cypress test maintenance
-- Migration to Playwright
-- Running existing Cypress tests
-
-## Quick Commands
-
-### Playwright
 ```bash
-# Run all Playwright tests
-npm run playwright:test
+cd superset-frontend
 
-# Run in headed mode (see browser)
-npm run playwright:headed
+# Run all tests
+npm run playwright:test
+# or: npx playwright test
 
 # Run specific test file
 npx playwright test tests/auth/login.spec.ts
 
-# Debug specific test
-npm run playwright:debug tests/auth/login.spec.ts
-
-# Open Playwright UI
+# Run with UI mode for debugging
 npm run playwright:ui
+# or: npx playwright test --ui
+
+# Run in headed mode (see browser)
+npm run playwright:headed
+# or: npx playwright test --headed
+
+# Debug specific test file
+npm run playwright:debug tests/auth/login.spec.ts
+# or: npx playwright test --debug tests/auth/login.spec.ts
 ```
 
 ### Cypress (Deprecated)
-```bash
-# Run Cypress tests
-cd superset-frontend/cypress-base
-npm run cypress-run-chrome
 
-# Open Cypress UI
-npm run cypress-debug
+Cypress tests are being migrated to Playwright. For legacy tests:
+
+```bash
+cd superset-frontend/cypress-base
+npm run cypress-run-chrome    # Headless
+npm run cypress-debug         # Interactive UI
 ```
 
----
+## Project Architecture
 
-*This documentation is under active development. Check back soon for updates!*
+```
+superset-frontend/playwright/
+├── components/core/     # Reusable UI components
+├── pages/              # Page Object Models
+├── tests/              # Test files organized by feature
+├── utils/              # Shared constants and utilities
+└── playwright.config.ts
+```
+
+## Design Principles
+
+We follow **YAGNI** (You Aren't Gonna Need It), **DRY** (Don't Repeat Yourself), and **KISS** (Keep It Simple, Stupid) principles:
+
+- Build only what's needed now
+- Reuse existing patterns and components
+- Keep solutions simple and maintainable
+
+## Page Object Pattern
+
+Each page object encapsulates:
+
+- **Actions**: What you can do on the page
+- **Queries**: Information you can get from the page
+- **Selectors**: Centralized in private static SELECTORS constant
+- **NO Assertions**: Keep assertions in test files
+
+**Example Page Object:**
+
+```typescript
+export class AuthPage {
+  // Selectors centralized in the page object
+  private static readonly SELECTORS = {
+    LOGIN_FORM: '[data-test="login-form"]',
+    USERNAME_INPUT: '[data-test="username-input"]',
+  } as const;
+
+  // Actions - what you can do
+  async loginWithCredentials(username: string, password: string) {}
+
+  // Queries - information you can get
+  async getCurrentUrl(): Promise<string> {}
+
+  // NO assertions - those belong in tests
+}
+```
+
+**Example Test:**
+
+```typescript
+import { test, expect } from '@playwright/test';
+import { AuthPage } from '../../pages/AuthPage';
+import { LOGIN } from '../../utils/urls';
+
+test('should login with correct credentials', async ({ page }) => {
+  const authPage = new AuthPage(page);
+  await authPage.goto();
+  await authPage.loginWithCredentials('admin', 'general');
+
+  // Assertions belong in tests, not page objects
+  expect(await authPage.getCurrentUrl()).not.toContain(LOGIN);
+});
+```
+
+## Core Components
+
+Reusable UI interaction classes for common elements (`components/core/`):
+
+- **Form**: Container with properly scoped child element access
+- **Input**: Supports `fill()`, `type()`, and `pressSequentially()` methods
+- **Button**: Standard click, hover, focus interactions
+
+**Usage Example:**
+
+```typescript
+import { Form } from '../components/core';
+
+const loginForm = new Form(page, '[data-test="login-form"]');
+const usernameInput = loginForm.getInput('[data-test="username-input"]');
+await usernameInput.fill('admin');
+```
+
+## Test Reports
+
+Playwright generates multiple reports for better visibility:
+
+```bash
+# View interactive HTML report (opens automatically on failure)
+npm run playwright:report
+# or: npx playwright show-report
+
+# View test trace for debugging failures
+npx playwright show-trace test-results/[test-name]/trace.zip
+```
+
+### Report Types
+
+- **List Reporter**: Shows progress and summary table in terminal
+- **HTML Report**: Interactive web interface with screenshots, videos, and traces
+- **JSON Report**: Machine-readable format in `test-results/results.json`
+- **GitHub Actions**: Annotations in CI for failed tests
+
+### Debugging Failed Tests
+
+When tests fail, Playwright automatically captures:
+
+- **Screenshots** at the point of failure
+- **Videos** of the entire test run
+- **Traces** with timeline and network activity
+- **Error context** with detailed debugging information
+
+All debugging artifacts are available in the HTML report for easy analysis.
+
+## Configuration
+
+- **Config**: `playwright.config.ts` - matches Cypress settings
+- **Base URL**: `http://localhost:8088` (assumes Superset running)
+- **Browsers**: Chrome only for Phase 1 (YAGNI)
+- **Retries**: 2 in CI, 0 locally (matches Cypress)
+
+## Contributing Guidelines
+
+### Adding New Tests
+
+1. **Check existing components** before creating new ones
+2. **Use page objects** for page interactions
+3. **Keep assertions in tests**, not page objects
+4. **Follow naming conventions**: `feature.spec.ts`
+
+### Adding New Components
+
+1. **Follow YAGNI**: Only build what's immediately needed
+2. **Use Locator-based scoping** for proper element isolation
+3. **Support both string selectors and Locator objects** via constructor overloads
+4. **Add to `components/core/index.ts`** for easy importing
+
+### Adding New Page Objects
+
+1. **Centralize selectors** in private static SELECTORS constant
+2. **Import shared constants** from `utils/urls.ts`
+3. **Actions and queries only** - no assertions
+4. **Use existing components** for DOM interactions
+
+## Migration from Cypress
+
+When porting Cypress tests:
+
+1. **Port the logic**, not the implementation
+2. **Use page objects** instead of inline selectors
+3. **Replace `cy.intercept/cy.wait`** with `page.waitForRequest()`
+4. **Use shared constants** from `utils/urls.ts`
+5. **Follow the established patterns** shown in `tests/auth/login.spec.ts`
+
+## Best Practices
+
+- **Centralize selectors** in page objects
+- **Centralize URLs** in `utils/urls.ts`
+- **Use meaningful test descriptions**
+- **Keep page objects action-focused**
+- **Put assertions in tests, not page objects**
+- **Follow the existing patterns** for consistency