chore: add playwright cursor skill

2026-05-13 17:52:38 +02:00 · 2026-05-10 04:19:55 +05:30 · 2026-05-10 04:19:55 +05:30 · d52225c18d
commit d52225c18d
parent 25aad38ca4
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--- a/.cursor/skills/playwright-testing/architecture/pom-vs-fixtures.md
+++ b/.cursor/skills/playwright-testing/architecture/pom-vs-fixtures.md
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+# Organizing Reusable Test Code
+
+## Table of Contents
+
+1. [Pattern Comparison](#pattern-comparison)
+2. [Selection Flowchart](#selection-flowchart)
+3. [Page Objects](#page-objects)
+4. [Custom Fixtures](#custom-fixtures)
+5. [Helper Functions](#helper-functions)
+6. [Combined Project Structure](#combined-project-structure)
+7. [Anti-Patterns](#anti-patterns)
+
+Use all three patterns together. Most projects benefit from a hybrid approach:
+
+- **Page objects** for UI interaction (pages/components with 5+ interactions)
+- **Custom fixtures** for test infrastructure (auth state, database, API clients, anything with lifecycle)
+- **Helper functions** for stateless utilities (generate data, format values, simple waits)
+
+If only using one pattern, choose **custom fixtures** — they handle setup/teardown, compose well, and Playwright is built around them.
+
+## Pattern Comparison
+
+| Aspect | Page Objects | Custom Fixtures | Helper Functions |
+|---|---|---|---|
+| **Purpose** | Encapsulate UI interactions | Provide resources with setup/teardown | Stateless utilities |
+| **Lifecycle** | Manual (constructor/methods) | Built-in (`use()` with automatic teardown) | None |
+| **Composability** | Constructor injection or fixture wiring | Depend on other fixtures | Call other functions |
+| **Best for** | Pages with many reused interactions | Resources needing setup AND teardown | Simple logic with no side effects |
+
+## Selection Flowchart
+
+```text
+What kind of reusable code?
+|
+-- Interacts with browser page/component?
+|   |
+|   +-- Has 5+ interactions (fill, click, navigate, assert)?
+|   |   +-- YES: Used in 3+ test files?
+|   |   |   +-- YES --> PAGE OBJECT
+|   |   |   +-- NO --> Inline or small helper
+|   |   +-- NO --> HELPER FUNCTION
+|   |
+|   +-- Needs setup before AND cleanup after test?
+|       +-- YES --> CUSTOM FIXTURE
+|       +-- NO --> PAGE OBJECT method or HELPER
+|
+-- Manages resource with lifecycle (create/destroy)?
+|   +-- Examples: auth state, DB connection, API client, test user
+|   +-- YES --> CUSTOM FIXTURE (always)
+|
+-- Stateless utility? (no browser, no side effects)
+|   +-- Examples: random email, format date, build URL, parse response
+|   +-- YES --> HELPER FUNCTION
+|
+-- Not sure?
+    +-- Start with HELPER FUNCTION
+    +-- Promote to PAGE OBJECT when interactions grow
+    +-- Promote to FIXTURE when lifecycle needed
+```
+
+## Page Objects
+
+Best for pages/components with 5+ interactions appearing in 3+ test files.
+
+```typescript
+// page-objects/booking.page.ts
+import { type Page, type Locator, expect } from '@playwright/test';
+
+export class BookingPage {
+  readonly page: Page;
+  readonly dateField: Locator;
+  readonly guestCount: Locator;
+  readonly roomType: Locator;
+  readonly reserveBtn: Locator;
+  readonly totalPrice: Locator;
+
+  constructor(page: Page) {
+    this.page = page;
+    this.dateField = page.getByLabel('Check-in date');
+    this.guestCount = page.getByLabel('Guests');
+    this.roomType = page.getByLabel('Room type');
+    this.reserveBtn = page.getByRole('button', { name: 'Reserve' });
+    this.totalPrice = page.getByTestId('total-price');
+  }
+
+  async goto() {
+    await this.page.goto('/booking');
+  }
+
+  async fillDetails(opts: { date: string; guests: number; room: string }) {
+    await this.dateField.fill(opts.date);
+    await this.guestCount.fill(String(opts.guests));
+    await this.roomType.selectOption(opts.room);
+  }
+
+  async reserve() {
+    await this.reserveBtn.click();
+    await this.page.waitForURL('**/confirmation');
+  }
+
+  async expectPrice(amount: string) {
+    await expect(this.totalPrice).toHaveText(amount);
+  }
+}
+```
+
+```typescript
+// tests/booking/reservation.spec.ts
+import { test, expect } from '@playwright/test';
+import { BookingPage } from '../page-objects/booking.page';
+
+test('complete reservation with standard room', async ({ page }) => {
+  const booking = new BookingPage(page);
+  await booking.goto();
+  await booking.fillDetails({ date: '2026-03-15', guests: 2, room: 'standard' });
+  await booking.reserve();
+  await expect(page.getByText('Reservation confirmed')).toBeVisible();
+});
+```
+
+**Page object principles:**
+- One class per logical page/component, not per URL
+- Constructor takes `Page`
+- Locators as `readonly` properties in constructor
+- Methods represent user intent (`reserve`, `fillDetails`), not low-level clicks
+- Navigation methods (`goto`) belong on the page object
+
+## Custom Fixtures
+
+Best for resources needing setup before and teardown after tests — auth state, database connections, API clients, test users.
+
+```typescript
+// fixtures/base.fixture.ts
+import { test as base, expect } from '@playwright/test';
+import { BookingPage } from '../page-objects/booking.page';
+import { generateMember } from '../helpers/data';
+
+type Fixtures = {
+  bookingPage: BookingPage;
+  member: { email: string; password: string; id: string };
+  loggedInPage: import('@playwright/test').Page;
+};
+
+export const test = base.extend<Fixtures>({
+  bookingPage: async ({ page }, use) => {
+    await use(new BookingPage(page));
+  },
+
+  member: async ({ request }, use) => {
+    const data = generateMember();
+    const res = await request.post('/api/test/members', { data });
+    const member = await res.json();
+    await use(member);
+    await request.delete(`/api/test/members/${member.id}`);
+  },
+
+  loggedInPage: async ({ page, member }, use) => {
+    await page.goto('/login');
+    await page.getByLabel('Email').fill(member.email);
+    await page.getByLabel('Password').fill(member.password);
+    await page.getByRole('button', { name: 'Sign in' }).click();
+    await expect(page).toHaveURL('/dashboard');
+    await use(page);
+  },
+});
+
+export { expect } from '@playwright/test';
+```
+
+```typescript
+// tests/dashboard/overview.spec.ts
+import { test, expect } from '../../fixtures/base.fixture';
+
+test('member sees dashboard widgets', async ({ loggedInPage }) => {
+  await expect(loggedInPage.getByRole('heading', { name: 'Dashboard' })).toBeVisible();
+  await expect(loggedInPage.getByTestId('stats-widget')).toBeVisible();
+});
+
+test('new member sees welcome prompt', async ({ loggedInPage, member }) => {
+  await expect(loggedInPage.getByText(`Welcome, ${member.email}`)).toBeVisible();
+});
+```
+
+**Fixture principles:**
+- Use `test.extend()` — never module-level variables
+- `use()` callback separates setup from teardown
+- Teardown runs even if test fails
+- Fixtures compose: one can depend on another
+- Fixtures are lazy: created only when requested
+- Wrap page objects in fixtures for lifecycle management
+
+## Helper Functions
+
+Best for stateless utilities — generating test data, formatting values, building URLs, parsing responses.
+
+```typescript
+// helpers/data.ts
+import { randomUUID } from 'node:crypto';
+
+export function generateEmail(prefix = 'user'): string {
+  return `${prefix}-${Date.now()}-${randomUUID().slice(0, 8)}@test.local`;
+}
+
+export function generateMember(overrides: Partial<Member> = {}): Member {
+  return {
+    email: generateEmail(),
+    password: 'SecurePass456!',
+    name: 'Test Member',
+    ...overrides,
+  };
+}
+
+interface Member {
+  email: string;
+  password: string;
+  name: string;
+}
+
+export function formatPrice(cents: number): string {
+  return `$${(cents / 100).toFixed(2)}`;
+}
+```
+
+```typescript
+// helpers/assertions.ts
+import { type Page, expect } from '@playwright/test';
+
+export async function expectNotification(page: Page, message: string): Promise<void> {
+  const notification = page.getByRole('alert').filter({ hasText: message });
+  await expect(notification).toBeVisible();
+  await expect(notification).toBeHidden({ timeout: 10000 });
+}
+```
+
+```typescript
+// tests/settings/account.spec.ts
+import { test, expect } from '@playwright/test';
+import { generateEmail } from '../../helpers/data';
+import { expectNotification } from '../../helpers/assertions';
+
+test('update account email', async ({ page }) => {
+  const newEmail = generateEmail('updated');
+  await page.goto('/settings/account');
+  await page.getByLabel('Email').fill(newEmail);
+  await page.getByRole('button', { name: 'Save' }).click();
+  await expectNotification(page, 'Account updated');
+  await expect(page.getByLabel('Email')).toHaveValue(newEmail);
+});
+```
+
+**Helper principles:**
+- Pure functions with no side effects
+- No browser state — take `page` as parameter if needed
+- Promote to fixture if setup/teardown needed
+- Promote to page object if many page interactions grow
+- Keep small and focused
+
+## Combined Project Structure
+
+```text
+tests/
+-- fixtures/
+|   +-- auth.fixture.ts
+|   +-- db.fixture.ts
+|   +-- base.fixture.ts
+-- page-objects/
+|   +-- login.page.ts
+|   +-- booking.page.ts
+|   +-- components/
+|       +-- data-table.component.ts
+-- helpers/
+|   +-- data.ts
+|   +-- assertions.ts
+-- e2e/
+|   +-- auth/
+|   |   +-- login.spec.ts
+|   +-- booking/
+|       +-- reservation.spec.ts
+playwright.config.ts
+```
+
+**Layer responsibilities:**
+
+| Layer | Pattern | Responsibility |
+|---|---|---|
+| **Test file** | `test()` | Describes behavior, orchestrates layers |
+| **Fixtures** | `test.extend()` | Resource lifecycle — setup, provide, teardown |
+| **Page objects** | Classes | UI interaction — navigation, actions, locators |
+| **Helpers** | Functions | Utilities — data generation, formatting, assertions |
+
+## Anti-Patterns
+
+### Page object managing resources
+
+```typescript
+// BAD: page object handling API calls and database
+class LoginPage {
+  async createUser() { /* API call */ }
+  async deleteUser() { /* API call */ }
+  async signIn(email: string, password: string) { /* UI */ }
+}
+```
+
+Resource lifecycle belongs in fixtures where teardown is guaranteed. Keep only `signIn` in the page object.
+
+### Locator-only page objects
+
+```typescript
+// BAD: no methods, just locators
+class LoginPage {
+  emailInput = this.page.getByLabel('Email');
+  passwordInput = this.page.getByLabel('Password');
+  submitBtn = this.page.getByRole('button', { name: 'Sign in' });
+  constructor(private page: Page) {}
+}
+```
+
+Add intent-revealing methods or skip the page object entirely.
+
+### Monolithic fixtures
+
+```typescript
+// BAD: one fixture doing everything
+test.extend({
+  everything: async ({ page, request }, use) => {
+    const user = await createUser(request);
+    const products = await seedProducts(request, 50);
+    await setupPayment(request, user.id);
+    await page.goto('/dashboard');
+    await use({ user, products, page });
+    // massive teardown...
+  },
+});
+```
+
+Break into small, composable fixtures. Each fixture does one thing.
+
+### Helpers with side effects
+
+```typescript
+// BAD: module-level state
+let createdUserId: string;
+
+export async function createTestUser(request: APIRequestContext) {
+  const res = await request.post('/api/users', { data: { email: 'test@example.com' } });
+  const user = await res.json();
+  createdUserId = user.id; // shared across tests!
+  return user;
+}
+```
+
+Module-level state leaks between parallel tests. If it has side effects and needs cleanup, make it a fixture.
+
+### Over-abstracting simple operations
+
+```typescript
+// BAD: helper for one-liner
+export async function clickButton(page: Page, name: string) {
+  await page.getByRole('button', { name }).click();
+}
+```
+
+Only abstract when there is real duplication (3+ usages) or complexity (5+ interactions).