What is frontend-testing?

A guide to testing frontend applications, including individual components, connected parts, and complete user flows in a browser.

Use it with Jest, Vitest, React Testing Library, or Cypress to test components, integrations, end-to-end flows, and user interactions.

It catches regressions when code changes and checks that interfaces behave correctly instead of relying only on manual testing.

frontend-testing — Skill for Claude Code and Codex by aj-geddes

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.

Any agent

npx skills add aj-geddes/useful-ai-prompts --skill frontend-testing

Clone the repo

git clone --depth 1 https://github.com/aj-geddes/useful-ai-prompts

Made for: Claude Code, Codex.

Wrote 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.

README.md

[![agentmods](https://agentmods.dev/badge/skills/aj-geddes/useful-ai-prompts/frontend-testing/github.svg)](https://agentmods.dev/skills/aj-geddes/useful-ai-prompts/frontend-testing)

Your own site

<a href="https://agentmods.dev/skills/aj-geddes/useful-ai-prompts/frontend-testing"><img src="https://agentmods.dev/badge/skills/aj-geddes/useful-ai-prompts/frontend-testing/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

Your own site · 80×15

<a href="https://agentmods.dev/skills/aj-geddes/useful-ai-prompts/frontend-testing"><img src="https://agentmods.dev/badge/skills/aj-geddes/useful-ai-prompts/frontend-testing.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 32 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 582 The whole file, excluding the scripts and references it only reads on demand.

Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe. Third-party audits

Socket pass 16 Sept 2026
Snyk pass 16 Sept 2026

How audits are shown

Origin original No closer match found 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.

Model	Per session	Once invoked
Fable 5.1	$0.00032	$0.00582
Opus 5.5	$0.00013	$0.00233
Sonnet 5.5	$0.00006	$0.00116
Haiku 4.5	$0.00003	$0.00058

Measured 2mo ago against content hash 137887fa0337, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

frontend-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 2mo ago.

The scan reads SKILL.md. This mod also ships 2 executable files (scripts/scaffold-tests.sh, templates/test-template.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.

skills/frontend-testing/SKILL.md · 91 lines

How it starts

The opening of the file, as written. The whole thing — 91 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Overview

Build comprehensive test suites for frontend applications including unit tests, integration tests, and end-to-end tests with proper coverage and assertions.

When to Use

Component testing
Integration testing
End-to-end testing
Regression prevention
Quality assurance
Test-driven development

Quick Start

Minimal working example:

// Button.test.tsx
import { render, screen, fireEvent } from '@testing-library/react';
import '@testing-library/jest-dom';
import { Button } from './Button';

describe('Button Component', () => {
  it('renders button with text', () => {
    render(<Button>Click me</Button>);
    expect(screen.getByRole('button')).toHaveTextContent('Click me');
  });

  it('calls onClick handler when clicked', () => {
    const handleClick = jest.fn();
    render(<Button onClick={handleClick}>Click</Button>);

    fireEvent.click(screen.getByRole('button'));
    expect(handleClick).toHaveBeenCalledTimes(1);
  });

  it('disables button when disabled prop is true', () => {
    render(<Button disabled>Click me</Button>);
    expect(screen.getByRole('button')).toBeDisabled();
  });

  it('applies variant styles correctly', () => {
// ... (see reference guides for full implementation)

Reference Guides

Detailed implementations in the references/ directory:

Guide	Contents
Jest Unit Testing (React)	Jest Unit Testing (React)
React Testing Library Integration Tests	React Testing Library Integration Tests
Vitest for Vue Testing	Vitest for Vue Testing
Cypress E2E Testing	Cypress E2E Testing
Test Coverage Configuration	Test Coverage Configuration

Read the full file on GitHub · 91 lines

Files

What ships with it

7 files 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.

2mo ago First seen · 91 lines · 32 tokens per session scan A 137887fa0337

Subscribe to this mod's changes

frontend-testing is a skill published in the GitHub repository aj-geddes/useful-ai-prompts (376 stars, last pushed 8mo ago), licensed MIT. It adds 32 tokens to every session and 582 once invoked, about $0.0001 per session on Opus 5.5. 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.

E2E testing Frontend Testing Unit testing

frontend-testing next to 6 skills from other repositories
Mod	Type	Stars	Last push	Licence	Scan	Tokens	Works with
frontend-testingaj-geddes/useful-ai-prompts	Skill	376	8mo ago	MIT	A	32	Claude Code, Codex
test-masterJeffallan/claude-skills	Skill	12k	7d ago	MIT	A	104	Claude Code
axiom-testingCharlesWiltgen/Axiom	Skill	1.3k	yesterday	MIT	A	38	Claude Code
test-generatorrshankras/claude-code-apple-skills	Skill	864	2d ago	MIT	A	33	Claude Code
testing-blocksadobe/skills	Skill	319	yesterday	Apache-2.0	A	61	Claude Code
designing-testsCloudAI-X/claude-workflow-v2	Skill	1.4k	1mo ago	MIT	A	48	Claude Code
test-automation-expertcuriositech/some_claude_skills	Skill	263	yesterday	MIT	A	133	Claude Code

frontend-testing