How do I install the Testing skill?

Run npx skillmds@latest add concertonotes/testing in your terminal (requires Node.js), paste this page's agent-chat prompt into Claude, Cursor, or any MCP-connected agent, or download the SKILL.md file and copy it into your agent's skills directory.

Is Testing safe to use?

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This skill is tagged as working with Claude Code, Claude.ai, OpenAI Codex. SKILL.md is an open format, so most agents that read a skills directory can load it too.

Is Testing free to use?

Yes. Installing skills from SkillMD is free, and the skill stays under its author's original license.

Who published Testing?

ConcertoNotes (@concertonotes) published this skill. Their other Agent Skills are listed on their SkillMD profile.

Testing by concertonotes — Agent Skill

Name: Testing
Rating: 4.5 (4 reviews)
Author: ConcertoNotes

File contents

You are an expert test engineer for JS/TS projects.

Read individual rule files in rules/ for detailed explanations and code examples.

Routing

Determine the test type from the user's request:

E2E / browser testing (keywords: "e2e", "end-to-end", "browser", "playwright", "page interaction", "screenshot") → Tell the user to use a browser/E2E testing skill instead and stop.
Unit / component testing → Proceed with the workflow below.

Rules Overview

Rule	Impact	File
Test structure	HIGH	`rules/test-structure.md`
Vitest patterns	HIGH	`rules/vitest-patterns.md`
Component testing	HIGH	`rules/component-testing.md`
Test quality	MEDIUM	`rules/test-quality.md`

Workflow

Step 1: Understand the Source

Read the source file(s) the user wants tested. Identify:

Exported functions, classes, or components
Dependencies and side effects
Edge cases and error paths

Step 2: Detect Project Setup

Scan the project to match existing conventions:

Test runner config: Glob for vitest.config.* or check vite.config.* for a test block
Existing tests: Glob for **/*.test.{ts,tsx} or **/*.spec.{ts,tsx} to find the naming convention
Test location: Check if tests are colocated next to source or in a separate __tests__/ directory
Package manager: Check for pnpm-lock.yaml, bun.lock, yarn.lock, or package-lock.json
RTL presence: Check package.json for @testing-library/react and @testing-library/user-event

Match the project's existing patterns for naming, location, and imports.

Step 3: Read Relevant Rules

Based on what is being tested:

Utility / logic functions → Read rules/test-structure.md and rules/vitest-patterns.md
React components → Also read rules/component-testing.md
Always consult rules/test-quality.md for quality guidelines

Step 4: Write Tests

Create the test file following project conventions:

Place the file according to the project's test location pattern
Use the project's naming convention (.test.ts or .spec.ts)
Follow the AAA pattern (Arrange, Act, Assert)
Cover the happy path, edge cases, and error cases

Step 5: Run and Verify

Run the tests using the project's test command:

# Use the project's package manager
pnpm run test          # or npm/bun/yarn equivalent
pnpm vitest run <file> # run a specific test file

Report results. If tests fail, read the error output, fix the test, and re-run.

Assumptions

Project uses Vitest as the test runner
React components are tested with React Testing Library
globals: true is set in Vitest config (no need to import describe, it, expect)

---name: testingdescription: Use when writing tests, running tests, adding test coverage, or debugging test failures. Unit and component testing with Vitest and React Testing Library.---You are an expert test engineer for JS/TS projects.Read individual rule files in `rules/` for detailed explanations and code examples.## RoutingDetermine the test type from the user's request:- **E2E / browser testing** (keywords: "e2e", "end-to-end", "browser", "playwright", "page interaction", "screenshot") → Tell the user to use a browser/E2E testing skill instead and stop.- **Unit / component testing** → Proceed with the workflow below.## Rules Overview| Rule | Impact | File ||------|--------|------|| Test structure | HIGH | `rules/test-structure.md` || Vitest patterns | HIGH | `rules/vitest-patterns.md` || Component testing | HIGH | `rules/component-testing.md` || Test quality | MEDIUM | `rules/test-quality.md` |## Workflow### Step 1: Understand the SourceRead the source file(s) the user wants tested. Identify:- Exported functions, classes, or components- Dependencies and side effects- Edge cases and error paths### Step 2: Detect Project SetupScan the project to match existing conventions:1. **Test runner config**: Glob for `vitest.config.*` or check `vite.config.*` for a `test` block2. **Existing tests**: Glob for `**/*.test.{ts,tsx}` or `**/*.spec.{ts,tsx}` to find the naming convention3. **Test location**: Check if tests are colocated next to source or in a separate `__tests__/` directory4. **Package manager**: Check for `pnpm-lock.yaml`, `bun.lock`, `yarn.lock`, or `package-lock.json`5. **RTL presence**: Check `package.json` for `@testing-library/react` and `@testing-library/user-event`Match the project's existing patterns for naming, location, and imports.### Step 3: Read Relevant RulesBased on what is being tested:- **Utility / logic functions** → Read `rules/test-structure.md` and `rules/vitest-patterns.md`- **React components** → Also read `rules/component-testing.md`- Always consult `rules/test-quality.md` for quality guidelines### Step 4: Write TestsCreate the test file following project conventions:1. Place the file according to the project's test location pattern2. Use the project's naming convention (`.test.ts` or `.spec.ts`)3. Follow the AAA pattern (Arrange, Act, Assert)4. Cover the happy path, edge cases, and error cases### Step 5: Run and VerifyRun the tests using the project's test command:```bash# Use the project's package managerpnpm run test # or npm/bun/yarn equivalentpnpm vitest run <file> # run a specific test file```Report results. If tests fail, read the error output, fix the test, and re-run.## Assumptions- Project uses Vitest as the test runner- React components are tested with React Testing Library- `globals: true` is set in Vitest config (no need to import `describe`, `it`, `expect`)

Frequently asked questions

Testing