Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx skills add cosmicstack-labs/mercury-agent-skills --skill e2e-testinggit clone --depth 1 https://github.com/cosmicstack-labs/mercury-agent-skillsWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/skills/cosmicstack-labs/mercury-agent-skills/e2e-testing)<a href="https://agentmods.dev/skills/cosmicstack-labs/mercury-agent-skills/e2e-testing"><img src="https://agentmods.dev/badge/skills/cosmicstack-labs/mercury-agent-skills/e2e-testing.svg" alt="Measured on agentmods" height="20"></a>- NVIDIA SkillSpector warn
SkillSpector: 1 finding, up to medium
These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →
- medium MCP Rug Pull · line 58 npx commands without a version suffix (e.g. @1.0.0) create a rug-pull risk if the upstream server is compromised and publishes a malicious update.Fix: Pin the version: npx @scope/[email protected]
What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00024 | $0.00486 |
| Opus 5 | $0.00012 | $0.00243 |
| Sonnet 5 | $0.00005 | $0.00097 |
| Haiku 4.5 | $0.00002 | $0.00049 |
Grade A, and why
e2e-testing scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 4d ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
What it actually says
E2E Testing
End-to-end testing with Playwright and Cypress.
Tool Choice
| Factor | Playwright | Cypress |
|---|---|---|
| Language | JS/TS, Python, C#, Java | JS/TS only |
| Browser support | Chromium, Firefox, WebKit | Chromium, Firefox, WebKit |
| Iframe support | Native | Limited |
| Network mocking | Route API | intercept() |
| Parallel execution | Built-in | Dashboard required |
Playwright Patterns
Selector Strategy (Priority Order)
getByRole()— best for accessibilitygetByText()— for text contentgetByTestId()— for complex componentsgetByLabel()— for form fieldslocator(CSS)— last resort
Test Structure
test.describe('Checkout Flow', () => {
test('completes purchase with valid card', async ({ page }) => {
await page.goto('/products');
await page.getByText('Add to Cart').first().click();
await page.getByRole('button', { name: 'Checkout' }).click();
await page.getByLabel('Card Number').fill('4242424242424242');
await page.getByRole('button', { name: 'Pay' }).click();
await expect(page.getByText('Thank you')).toBeVisible();
});
});
Visual Testing
- Use
await expect(page).toHaveScreenshot() - Maintain baseline screenshots in version control
- Run visual tests on CI with 1% threshold
- Use percy.io or Chromatic for cloud-based visual review
CI Integration
# GitHub Actions
- name: E2E Tests
run: npx playwright test
- uses: actions/upload-artifact
if: failure()
with:
name: playwright-report
path: playwright-report/
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 4d ago First seen · 65 lines · 24 tokens per session scan A 95417500064d
e2e-testing is a skill published in the GitHub repository cosmicstack-labs/mercury-agent-skills (471 stars, last pushed 13d ago), licensed MIT. It adds 24 tokens to every session and 486 once invoked, about $0.0001 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-03.
Other skills, from other repositories
browser-testing-with-devtools
Tests in real browsers via Chrome DevTools MCP. Use when building or debugging anything that runs in a browser. Use when you need to inspect the DOM, capture console errors, analyze network requests, profile performance, or verify visual output with real runtime data. Requires the chrome-devtools MCP server to be…
actionbook-web-test
Run browser-based web tests against websites using Actionbook CLI. Activate when the user wants to test a website workflow, run smoke tests, verify a user flow, check if a web application works, run regression tests, or validate browser-based interactions. Supports test definition, execution, assertion, reporting, and…
web-test
A browser-automation tool for testing the 1C:Enterprise web client. It uses Playwright to navigate sections, fill forms, read tables and reports, and perform user actions in a browser.
playwright-visual-testing
Add, repair, or review Playwright visual regression tests for browser-facing .NET apps, including screenshot baselines, Pixelmatch thresholds, deterministic rendering, and GitHub Actions artifacts. USE FOR: toHaveScreenshot, page.screenshot visual checks, Pixelmatch/pngjs comparison scripts, visual baseline updates…
qa-systematic
Systematic web application QA testing with issue taxonomy, health scoring, and regression tracking. Triggers on: "QA this", "test the app", "smoke test", "run QA", "systematic test", "regression test", "full QA", "/qa-systematic".
appbuilder-e2e-testing
Use this skill whenever the user wants browser-based end-to-end tests for an Adobe App Builder application. Covers Playwright E2E testing for ExC Shell SPAs, AEM extension UIs, and full-stack flows. Use when the user mentions: "E2E test", "end-to-end test", "Playwright", "browser test", "test my SPA in the browser"…