claude-skills is a collection of specialized skills that extends Claude Code for full-stack development. Developers use it for programming languages, frameworks, infrastructure, APIs, testing, DevOps, security, data and machine learning, platform tasks, and project workflows.
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 Jeffallan/claude-skills --skill test-mastergit clone --depth 1 https://github.com/Jeffallan/claude-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/jeffallan/claude-skills/test-master)<a href="https://agentmods.dev/skills/jeffallan/claude-skills/test-master"><img src="https://agentmods.dev/badge/skills/jeffallan/claude-skills/test-master/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.
<a href="https://agentmods.dev/skills/jeffallan/claude-skills/test-master"><img src="https://agentmods.dev/badge/skills/jeffallan/claude-skills/test-master.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- Socket pass
- Snyk pass
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 | $0.00104 | $0.01148 |
| Opus 5.5 | $0.00042 | $0.00459 |
| Sonnet 5.5 | $0.00021 | $0.00230 |
| Haiku 4.5 | $0.00010 | $0.00115 |
Grade A, and why
test-master 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.
Copies of this mod
2 near-identical copies found in the catalogue:
- test-master — 91% identical, 9 lines differ
- Qtest-master — 78% identical, 122 lines differ
How it starts
The opening of the file, as written. The whole thing — 100 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Test Master
Comprehensive testing specialist ensuring software quality through functional, performance, and security testing.
Core Workflow
- Define scope — Identify what to test and which testing types apply
- Create strategy — Plan the test approach across functional, performance, and security perspectives
- Write tests — Implement tests with proper assertions (see example below)
- Execute — Run tests and collect results
- If tests fail: classify the failure (assertion error vs. environment/flakiness), fix root cause, re-run
- If tests are flaky: isolate ordering dependencies, check async handling, add retry or stabilization logic
- Report — Document findings with severity ratings and actionable fix recommendations
- Verify coverage targets are met before closing; flag gaps explicitly
Quick-Start Example
A minimal Jest unit test illustrating the key patterns this skill enforces:
// ✅ Good: meaningful description, specific assertion, isolated dependency
describe('calculateDiscount', () => {
it('applies 10% discount for premium users', () => {
const result = calculateDiscount({ price: 100, userTier: 'premium' });
expect(result).toBe(90); // specific outcome, not just truthy
});
it('throws on negative price', () => {
expect(() => calculateDiscount({ price: -1, userTier: 'standard' }))
.toThrow('Price must be non-negative');
});
});
Apply the same structure for pytest (def test_…, assert result == expected) and other frameworks.
Reference Guide
Load detailed guidance based on context:
| Topic | Reference | Load When |
|---|---|---|
| Unit Testing | references/unit-testing.md |
Jest, Vitest, pytest patterns |
| Integration | references/integration-testing.md |
API testing, Supertest |
| E2E | references/e2e-testing.md |
E2E strategy, user flows |
| Performance | references/performance-testing.md |
k6, load testing |
| Security | references/security-testing.md |
Security test checklist |
| Reports | references/test-reports.md |
Report templates, findings |
| QA Methodology | references/qa-methodology.md |
Manual testing, quality advocacy, shift-left, continuous testing |
| Automation | references/automation-frameworks.md |
Framework patterns, scaling, maintenance, team enablement |
| TDD Iron Laws | references/tdd-iron-laws.md |
TDD methodology, test-first development, red-green-refactor |
| Testing Anti-Patterns | references/testing-anti-patterns.md |
Test review, mock issues, test quality problems |
What ships with it
10 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.
- references/automation-frameworks.md 7.2 KB
- references/e2e-testing.md 3.3 KB
- references/integration-testing.md 2.7 KB
- references/performance-testing.md 2.6 KB
- references/qa-methodology.md 6.2 KB
- references/security-testing.md 3.3 KB
- references/tdd-iron-laws.md 4.3 KB
- references/test-reports.md 2.3 KB
- references/testing-anti-patterns.md 6.4 KB
- references/unit-testing.md 2.7 KB
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 · 100 lines · 104 tokens per session scan A 93c3710547af
test-master is a skill published in the GitHub repository Jeffallan/claude-skills (11,766 stars, last pushed 4d ago), licensed MIT. It adds 104 tokens to every session and 1,148 once invoked, about $0.0004 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 2026-10-04.
Other skills, from other repositories
req-to-test
Generates comprehensive test scenarios from requirements including BDD/Gherkin scenarios, unit tests, integration tests, and end-to-end test cases. Use when converting requirements, user stories, or specifications into testable scenarios with full coverage including happy paths, error cases, edge cases, and boundary…
ios-testing
Invoke any time a user is writing iOS/Swift tests or asking why tests behave a certain way — including XCTest versus Swift Testing (@Test/#expect) choices, async ViewModel tests with @Observable or @Published, snapshot testing across device sizes, mocking protocols for dependency injection, setUp/tearDown lifecycle…
test-strategy-document
Create a production-ready Testing Strategy and QA Execution Plan. Covers testing levels (unit, integration, E2E, performance), mocking boundaries, test environment matrix, code coverage thresholds, and automated CI pipeline runsheets. Use when establishing a QA framework for a new system or feature set.
test-strategy
Use when deciding what to test and at which level. Covers the test pyramid, what belongs in unit versus integration versus end-to-end tests, coverage as a signal rather than a target, and eliminating flakiness.
writing-tests
Write unit, integration, and E2E tests that follow the testing pyramid, the Arrange-Act-Assert pattern, the shouldXwhenY naming convention, and meet a 75% (target 80%) branch coverage gate per supported OS. Use when the user asks to write tests, add coverage, build a test suite, fix flaky tests, or verify a feature…
test-levels
This skill explains the 3 test levels (Unit, Integration, E2E) using the "Building a Car" analogy and provides guidance on when to use each type. Includes project-specific Playwright examples.