webapp-testing

A browser-based toolkit for testing and debugging local web applications with Playwright, a tool that automates real browser actions.

In plain words
What is it for?
Use it to navigate pages, click controls, fill forms, check responsive layouts, verify URLs and text, capture screenshots, and inspect browser logs.
Why use it?
It helps verify what users see and do in a browser, while exposing failed interactions, console messages, network problems, and layout issues.

Skill for Claude CodeCodex

Install

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.

agentmods
npx agentmods add skills/amir0135/github-copilot-use-cases/webapp-testing
Any agent
npx skills add amir0135/github-copilot-use-cases --skill webapp-testing
Clone the repo
git clone --depth 1 https://github.com/amir0135/github-copilot-use-cases

Made for: Claude Code, Codex.

Per session 35 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 711 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin 100% copy Near-identical to another mod in the catalogue.
Token cost

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.

ModelPer sessionOnce invoked
Fable 5 $0.00035 $0.00711
Opus 5 $0.00017 $0.00356
Sonnet 5 $0.00007 $0.00142
Haiku 4.5 $0.00003 $0.00071

Measured 2d ago against content hash 31e301853c09, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

webapp-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 2d ago.

The scan reads SKILL.md. This mod also ships 1 executable file (test-helper.js), listed below but not scanned — reading those needs a real analyzer, not pattern matching.

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.

Origin

This is a copy

100% identical to webapp-testing — 0 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

.github/skills/webapp-testing/SKILL.md · 117 lines

How it starts

The opening of the file, as written. The whole thing — 117 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Web Application Testing

This skill enables comprehensive testing and debugging of local web applications using Playwright automation.

When to Use This Skill

Use this skill when you need to:

  • Test frontend functionality in a real browser
  • Verify UI behavior and interactions
  • Debug web application issues
  • Capture screenshots for documentation or debugging
  • Inspect browser console logs
  • Validate form submissions and user flows
  • Check responsive design across viewports

Prerequisites

  • Node.js installed on the system
  • A locally running web application (or accessible URL)
  • Playwright will be installed automatically if not present

Core Capabilities

1. Browser Automation

  • Navigate to URLs
  • Click buttons and links
  • Fill form fields
  • Select dropdowns
  • Handle dialogs and alerts

2. Verification

  • Assert element presence
  • Verify text content
  • Check element visibility
  • Validate URLs
  • Test responsive behavior

3. Debugging

  • Capture screenshots
  • View console logs
  • Inspect network requests
  • Debug failed tests

Usage Examples

Example 1: Basic Navigation Test

// Navigate to a page and verify title
await page.goto('http://localhost:3000');
const title = await page.title();
console.log('Page title:', title);

Example 2: Form Interaction

// Fill out and submit a form
await page.fill('#username', 'testuser');
await page.fill('#password', 'password123');
await page.click('button[type="submit"]');
await page.waitForURL('**/dashboard');

Example 3: Screenshot Capture

// Capture a screenshot for debugging
await page.screenshot({ path: 'debug.png', fullPage: true });

Guidelines

  1. Always verify the app is running - Check that the local server is accessible before running tests
  2. Use explicit waits - Wait for elements or navigation to complete before interacting
  3. Capture screenshots on failure - Take screenshots to help debug issues
  4. Clean up resources - Always close the browser when done
  5. Handle timeouts gracefully - Set reasonable timeouts for slow operations
  6. Test incrementally - Start with simple interactions before complex flows
  7. Use selectors wisely - Prefer data-testid or role-based selectors over CSS classes

Read the full file on GitHub · 117 lines

Files

What ships with it

1 file beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

Changes

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.

  1. 2d ago First seen · 117 lines · 35 tokens per session scan A 31e301853c09

Subscribe to this mod's changes

webapp-testing is a skill published in the GitHub repository amir0135/github-copilot-use-cases (2 stars, last pushed 21d ago), licensed MIT. It adds 35 tokens to every session and 711 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 0 findings. It is 100% identical to webapp-testing, differing in 0 lines, and is treated as a copy.

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