8.7 KiB
Playwright Utils Overview
Principle
Use production-ready, fixture-based utilities from @seontechnologies/playwright-utils for common Playwright testing patterns. Build test helpers as pure functions first, then wrap in framework-specific fixtures for composability and reuse.
Rationale
Writing Playwright utilities from scratch for every project leads to:
- Duplicated code across test suites
- Inconsistent patterns and quality
- Maintenance burden when Playwright APIs change
- Missing advanced features (schema validation, HAR recording, auth persistence)
@seontechnologies/playwright-utils provides:
- Production-tested utilities: Used at SEON Technologies in production
- Functional-first design: Core logic as pure functions, fixtures for convenience
- Composable fixtures: Use
mergeTeststo combine utilities - TypeScript support: Full type safety with generic types
- Comprehensive coverage: API requests, auth, network, logging, file handling, burn-in
Installation
npm install -D @seontechnologies/playwright-utils
Peer Dependencies:
@playwright/test>= 1.54.1 (required)ajv>= 8.0.0 (optional - for JSON Schema validation)js-yaml>= 4.0.0 (optional - for YAML schema support)zod>= 3.0.0 (optional - for Zod schema validation)
Available Utilities
Core Testing Utilities
| Utility | Purpose | Test Context |
|---|---|---|
| api-request | Typed HTTP client with schema validation | API tests |
| network-recorder | HAR record/playback for offline testing | UI tests |
| auth-session | Token persistence, multi-user auth | Both UI & API |
| recurse | Cypress-style polling for async conditions | Both UI & API |
| intercept-network-call | Network spy/stub with auto JSON parsing | UI tests |
| log | Playwright report-integrated logging | Both UI & API |
| file-utils | CSV/XLSX/PDF/ZIP reading & validation | Both UI & API |
| burn-in | Smart test selection with git diff | CI/CD |
| network-error-monitor | Automatic HTTP 4xx/5xx detection | UI tests |
Design Patterns
Pattern 1: Functional Core, Fixture Shell
Context: All utilities follow the same architectural pattern - pure function as core, fixture as wrapper.
Implementation:
// Direct import (pass Playwright context explicitly)
import { apiRequest } from '@seontechnologies/playwright-utils';
test('direct usage', async ({ request }) => {
const { status, body } = await apiRequest({
request, // Must pass request context
method: 'GET',
path: '/api/users',
});
});
// Fixture import (context injected automatically)
import { test } from '@seontechnologies/playwright-utils/fixtures';
test('fixture usage', async ({ apiRequest }) => {
const { status, body } = await apiRequest({
// No need to pass request context
method: 'GET',
path: '/api/users',
});
});
Key Points:
- Pure functions testable without Playwright running
- Fixtures inject framework dependencies automatically
- Choose direct import (more control) or fixture (convenience)
Pattern 2: Subpath Imports for Tree-Shaking
Context: Import only what you need to keep bundle sizes small.
Implementation:
// Import specific utility
import { apiRequest } from '@seontechnologies/playwright-utils/api-request';
// Import specific fixture
import { test } from '@seontechnologies/playwright-utils/api-request/fixtures';
// Import everything (use sparingly)
import { apiRequest, recurse, log } from '@seontechnologies/playwright-utils';
Key Points:
- Subpath imports enable tree-shaking
- Keep bundle sizes minimal
- Import from specific paths for production builds
Pattern 3: Fixture Composition with mergeTests
Context: Combine multiple playwright-utils fixtures with your own custom fixtures.
Implementation:
// playwright/support/merged-fixtures.ts
import { mergeTests } from '@playwright/test';
import { test as apiRequestFixture } from '@seontechnologies/playwright-utils/api-request/fixtures';
import { test as authFixture } from '@seontechnologies/playwright-utils/auth-session/fixtures';
import { test as recurseFixture } from '@seontechnologies/playwright-utils/recurse/fixtures';
import { test as logFixture } from '@seontechnologies/playwright-utils/log/fixtures';
// Merge all fixtures into one test object
export const test = mergeTests(apiRequestFixture, authFixture, recurseFixture, logFixture);
export { expect } from '@playwright/test';
// In your tests
import { test, expect } from '../support/merged-fixtures';
test('all utilities available', async ({ apiRequest, authToken, recurse, log }) => {
await log.step('Making authenticated API request');
const { body } = await apiRequest({
method: 'GET',
path: '/api/protected',
headers: { Authorization: `Bearer ${authToken}` },
});
await recurse(
() => apiRequest({ method: 'GET', path: `/status/${body.id}` }),
(res) => res.body.ready === true,
);
});
Key Points:
mergeTestscombines multiple fixtures without conflicts- Create one merged-fixtures.ts file per project
- Import test object from your merged fixtures in all tests
- All utilities available in single test signature
Integration with Existing Tests
Gradual Adoption Strategy
1. Start with logging (zero breaking changes):
import { log } from '@seontechnologies/playwright-utils';
test('existing test', async ({ page }) => {
await log.step('Navigate to page'); // Just add logging
await page.goto('/dashboard');
// Rest of test unchanged
});
2. Add API utilities (for API tests):
import { test } from '@seontechnologies/playwright-utils/api-request/fixtures';
test('API test', async ({ apiRequest }) => {
const { status, body } = await apiRequest({
method: 'GET',
path: '/api/users',
});
expect(status).toBe(200);
});
3. Expand to network utilities (for UI tests):
import { test } from '@seontechnologies/playwright-utils/fixtures';
test('UI with network control', async ({ page, interceptNetworkCall }) => {
const usersCall = interceptNetworkCall({
url: '**/api/users',
});
await page.goto('/dashboard');
const { responseJson } = await usersCall;
expect(responseJson).toHaveLength(10);
});
4. Full integration (merged fixtures):
Create merged-fixtures.ts and use across all tests.
Related Fragments
api-request.md- HTTP client with schema validationnetwork-recorder.md- HAR-based offline testingauth-session.md- Token managementintercept-network-call.md- Network interceptionrecurse.md- Polling patternslog.md- Logging utilityfile-utils.md- File operationsfixtures-composition.md- Advanced mergeTests patterns
Anti-Patterns
❌ Don't mix direct and fixture imports in same test:
import { apiRequest } from '@seontechnologies/playwright-utils';
import { test } from '@seontechnologies/playwright-utils/auth-session/fixtures';
test('bad', async ({ request, authToken }) => {
// Confusing - mixing direct (needs request) and fixture (has authToken)
await apiRequest({ request, method: 'GET', path: '/api/users' });
});
✅ Use consistent import style:
import { test } from '../support/merged-fixtures';
test('good', async ({ apiRequest, authToken }) => {
// Clean - all from fixtures
await apiRequest({ method: 'GET', path: '/api/users' });
});
❌ Don't import everything when you need one utility:
import * as utils from '@seontechnologies/playwright-utils'; // Large bundle
✅ Use subpath imports:
import { apiRequest } from '@seontechnologies/playwright-utils/api-request'; // Small bundle
Reference Implementation
The official @seontechnologies/playwright-utils repository provides working examples of all patterns described in these fragments.
Repository: https://github.com/seontechnologies/playwright-utils
Key resources:
- Test examples:
playwright/tests- All utilities in action - Framework setup:
playwright.config.ts,playwright/support/merged-fixtures.ts - CI patterns:
.github/workflows/- GitHub Actions with sharding, parallelization
Quick start:
git clone https://github.com/seontechnologies/playwright-utils.git
cd playwright-utils
nvm use
npm install
npm run test:pw-ui # Explore tests with Playwright UI
npm run test:pw
All patterns in TEA fragments are production-tested in this repository.