DevOps & Tooling · Cursor
Playwright E2E Cursor Rules (.mdc)
Generate Playwright Cursor rules enforcing user-facing locators (getByRole, getByText), auto-waiting assertions, page object models, and zero sleep() calls.
- Path
- .cursor/rules/playwright.mdc
- Loads
- Glob pattern match
- Format
- Frontmatter MDC (.mdc)
- Used by
- Cursor
What this file tells the agent
AI models frequently write fragile test automation scripts with brittle CSS/XPath selectors (e.g. div > span:nth-child(3)), hardcoded page.waitForTimeout() delays, and un-isolated test state, leading to flaky test suites.
- Strictly ban hardcoded delays (page.waitForTimeout()); rely exclusively on Playwright web-first auto-waiting assertions (expect(locator).toBeVisible()).
- Prioritize user-facing accessible locators: page.getByRole(), page.getByLabel(), and page.getByTestId(); never write fragile CSS selectors or brittle XPaths.
- Encapsulate multi-step interactions inside modular Page Object Models (POM) with typed parameters.
- Ensure total test isolation: authenticate via storage state (storageState) instead of repeating manual UI logins in every test.
- Configure trace viewer and video capture on first retry (trace: 'on-first-retry') for painless CI debugging.
Code to avoid, and what to write instead
The rule steers the agent away from the left and toward the right.
// Flaky: Brittle selectors, arbitrary sleep timeouts, and no auto-waiting
test("bad test", async ({ page }) => {
await page.goto("/catalog");
await page.click("div.col-md-4 > button:nth-child(2)"); // Breaks on minor CSS tweak!
await page.waitForTimeout(5000); // Flaky anti-pattern!
const text = await page.innerText("#cart-total");
expect(text).toBe("1");
});import { test, expect } from "@playwright/test";
test.describe("Checkout Flow", () => {
test("allows user to complete cart purchase", async ({ page }) => {
await page.goto("/catalog");
// Accessible, user-facing locators
await page.getByRole("button", { name: "Add to Cart" }).first().click();
await page.getByRole("link", { name: "Cart (1)" }).click();
// Auto-waiting assertions
await expect(page.getByRole("heading", { name: "Your Shopping Cart" })).toBeVisible();
await page.getByRole("button", { name: "Proceed to Checkout" }).click();
await expect(page).toHaveURL(/.*checkout/);
});
});Install it in one command
- 01
Go to your project root
The file goes at .cursor/rules/playwright.mdc, relative to the root.
- 02
Download the file
Run the command on the right. It downloads this preset and writes the file.
- 03
Make sure it gets used
Cursor picks up rules in .cursor/rules/ automatically. This one attaches when files matching its globs are in the request, or when you @-mention it.
$ mkdir -p ".cursor/rules" && curl -fsSL "https://www.devscratchpad.tech/api/raw/cursor-rules/playwright-e2e" -o ".cursor/rules/playwright.mdc"
writes .cursor/rules/playwright.mdc
.cursor/rules/playwright.mdc
To write the file from your own code instead, use Read your code or Convert Legacy Rules in the editor above.
More for Playwright End-to-End Testing
Questions
- Why are arbitrary sleep timeouts banned?
- Arbitrary delays like waitForTimeout waste CI test execution time and still fail randomly under variable network latency. Playwright auto-waiting assertions check conditions dynamically.
- Why use getByRole instead of class names?
- getByRole verifies that elements are accessible to screen readers and resilient to CSS redesigns.