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End-to-end testing patterns with Playwright for full-stack Python/React applications. Use when writing E2E tests for complete user workflows (login, CRUD, navigation), critical path regression tests, or cross-browser validation. Covers test structure, page object model, selector strategy (data-testid > role > label), wait strategies, auth state reuse, test data management, and CI integration. Does NOT cover unit tests or component tests (use pytest-patterns or react-testing-patterns).
npx skill4agent add hieutrtr/ai1-skills e2e-testingreact-testing-patternspytest-patternstdd-workflowpytest-patternse2e/
├── playwright.config.ts # Global Playwright configuration
├── fixtures/
│ ├── auth.fixture.ts # Authentication state setup
│ └── test-data.fixture.ts # Test data creation/cleanup
├── pages/
│ ├── base.page.ts # Base page object with shared methods
│ ├── login.page.ts # Login page object
│ ├── users.page.ts # Users list page object
│ └── user-detail.page.ts # User detail page object
├── tests/
│ ├── auth/
│ │ ├── login.spec.ts
│ │ └── logout.spec.ts
│ ├── users/
│ │ ├── create-user.spec.ts
│ │ ├── edit-user.spec.ts
│ │ └── list-users.spec.ts
│ └── smoke/
│ └── critical-paths.spec.ts
└── utils/
├── api-helpers.ts # Direct API calls for test setup
└── test-constants.ts # Shared constants<feature>.spec.ts<page-name>.page.ts<concern>.fixture.ts// e2e/pages/base.page.ts
import { type Page, type Locator } from "@playwright/test";
export abstract class BasePage {
constructor(protected readonly page: Page) {}
/** Navigate to the page's URL. */
abstract goto(): Promise<void>;
/** Wait for the page to be fully loaded. */
async waitForLoad(): Promise<void> {
await this.page.waitForLoadState("networkidle");
}
/** Get a toast/notification message. */
get toast(): Locator {
return this.page.getByRole("alert");
}
/** Get the page heading. */
get heading(): Locator {
return this.page.getByRole("heading", { level: 1 });
}
}// e2e/pages/users.page.ts
import { type Page, type Locator } from "@playwright/test";
import { BasePage } from "./base.page";
export class UsersPage extends BasePage {
// ─── Locators ─────────────────────────────────────────
readonly createButton: Locator;
readonly searchInput: Locator;
readonly userTable: Locator;
constructor(page: Page) {
super(page);
this.createButton = page.getByTestId("create-user-btn");
this.searchInput = page.getByRole("searchbox", { name: /search users/i });
this.userTable = page.getByRole("table");
}
// ─── Actions ──────────────────────────────────────────
async goto(): Promise<void> {
await this.page.goto("/users");
await this.waitForLoad();
}
async searchFor(query: string): Promise<void> {
await this.searchInput.fill(query);
// Wait for search results to update (debounced)
await this.page.waitForResponse("**/api/v1/users?*");
}
async clickCreateUser(): Promise<void> {
await this.createButton.click();
}
async getUserRow(email: string): Promise<Locator> {
return this.userTable.getByRole("row").filter({ hasText: email });
}
async getUserCount(): Promise<number> {
// Subtract 1 for header row
return (await this.userTable.getByRole("row").count()) - 1;
}
}| Priority | Selector | Example | When to Use |
|---|---|---|---|
| 1 | | | Interactive elements, dynamic content |
| 2 | Role | | Buttons, links, headings, inputs |
| 3 | Label | | Form inputs with labels |
| 4 | Placeholder | | Search inputs |
| 5 | Text | | Static text content |
.class-name#id//div[@class="foo"]div > span:nth-child(2)// In React components -- add data-testid to interactive elements
<button data-testid="create-user-btn" onClick={handleCreate}>
Create User
</button>
// Convention: kebab-case, descriptive
// Pattern: <action>-<entity>-<element-type>
// Examples: create-user-btn, user-email-input, delete-confirm-dialog// BAD: Hardcoded wait -- flaky, slow
await page.waitForTimeout(3000);
// BAD: Sleep
await new Promise((resolve) => setTimeout(resolve, 2000));// GOOD: Wait for a specific element to appear
await page.getByRole("heading", { name: "Dashboard" }).waitFor();
// GOOD: Wait for navigation
await page.waitForURL("/dashboard");
// GOOD: Wait for API response
await page.waitForResponse(
(response) =>
response.url().includes("/api/v1/users") && response.status() === 200,
);
// GOOD: Wait for network to settle
await page.waitForLoadState("networkidle");
// GOOD: Wait for element state
await page.getByTestId("submit-btn").waitFor({ state: "visible" });
await page.getByTestId("loading-spinner").waitFor({ state: "hidden" });// e2e/fixtures/auth.fixture.ts
import { test as base } from "@playwright/test";
import path from "path";
const AUTH_STATE_PATH = path.resolve("e2e/.auth/user.json");
export const setup = base.extend({});
setup("authenticate", async ({ page }) => {
// Perform real login
await page.goto("/login");
await page.getByLabel("Email").fill("testuser@example.com");
await page.getByLabel("Password").fill("TestPassword123!");
await page.getByRole("button", { name: /sign in/i }).click();
// Wait for auth to complete
await page.waitForURL("/dashboard");
// Save signed-in state
await page.context().storageState({ path: AUTH_STATE_PATH });
});// playwright.config.ts
export default defineConfig({
projects: [
// Setup project runs first and saves auth state
{ name: "setup", testDir: "./e2e/fixtures", testMatch: "auth.fixture.ts" },
{
name: "chromium",
use: {
storageState: "e2e/.auth/user.json", // Reuse auth state
},
dependencies: ["setup"],
},
],
});// e2e/utils/api-helpers.ts
import { type APIRequestContext } from "@playwright/test";
export class TestDataAPI {
constructor(private request: APIRequestContext) {}
async createUser(data: { email: string; displayName: string }) {
const response = await this.request.post("/api/v1/users", { data });
return response.json();
}
async deleteUser(userId: number) {
await this.request.delete(`/api/v1/users/${userId}`);
}
async createOrder(userId: number, items: Array<Record<string, unknown>>) {
const response = await this.request.post("/api/v1/orders", {
data: { user_id: userId, items },
});
return response.json();
}
}test("edit user name", async ({ page, request }) => {
const api = new TestDataAPI(request);
// Setup: create user via API (fast)
const user = await api.createUser({
email: "edit-test@example.com",
displayName: "Before Edit",
});
try {
// Test: edit via UI
const usersPage = new UsersPage(page);
await usersPage.goto();
// ... perform edit via UI ...
} finally {
// Cleanup: remove test data
await api.deleteUser(user.id);
}
});// playwright.config.ts
use: {
trace: "on-first-retry", // Capture trace only on retry
}npx playwright show-trace trace.zipnpx playwright test --headed --debug tests/users/create-user.spec.ts| Cause | Fix |
|---|---|
| Hardcoded waits | Use explicit wait conditions |
| Shared test data | Each test creates its own data |
| Animation interference | Set |
| Race conditions | Wait for API responses before assertions |
| Viewport-dependent behavior | Set explicit viewport in config |
| Session leaks between tests | Use |
// playwright.config.ts
export default defineConfig({
retries: process.env.CI ? 2 : 0, // Retry in CI only
});# .github/workflows/e2e.yml
name: E2E Tests
on:
push:
branches: [main]
pull_request:
branches: [main]
jobs:
e2e:
runs-on: ubuntu-latest
steps:
- uses: actions/checkout@v4
- uses: actions/setup-node@v4
with:
node-version: 20
cache: npm
- name: Install dependencies
run: npm ci
- name: Install Playwright browsers
run: npx playwright install --with-deps chromium
- name: Start application
run: |
docker compose up -d
npx wait-on http://localhost:3000 --timeout 60000
- name: Run E2E tests
run: npx playwright test
- name: Upload test report
if: always()
uses: actions/upload-artifact@v4
with:
name: playwright-report
path: playwright-report/
retention-days: 14
- name: Upload traces on failure
if: failure()
uses: actions/upload-artifact@v4
with:
name: test-traces
path: test-results/scripts/run-e2e-with-report.shreferences/page-object-template.tsreferences/e2e-test-template.tsreferences/playwright-config-example.ts