Test Expert
einverne/dotfiles
Testing methodologies, test-driven development (TDD), unit and integration testing, and testing best practices across multiple frameworks.
Write unit tests for any function — happy path, edge cases, and error cases.
Install Test Writer
$ npx skills add hamzafarooq/claude-code-starter --skill test-writer -a claude-codeProject install by default; add -g for ~/.claude/skills/.
$ gh skill install hamzafarooq/claude-code-starter test-writer --agent claude-codeProject scope by default; add --scope user for a personal install. Needs GitHub CLI 2.90.0 or later (public preview).
$ git clone --depth 1 https://github.com/hamzafarooq/claude-code-starter.git skills-src && mkdir -p .claude/skills && cp -r skills-src/.claude/skills/test-writer .claude/skills/test-writer && rm -rf skills-srcUse ~/.claude/skills/ instead of .claude/skills for a personal install. The folder must contain SKILL.md.
Claude Code skills documentation · loads skills from .claude/skills/
Install the "test-writer" agent skill from https://github.com/hamzafarooq/claude-code-starter/tree/main/.claude/skills/test-writer into .claude/skills/test-writer/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "test-writer", then confirm the skill loads.Claude Code copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$skill-installer install https://github.com/hamzafarooq/claude-code-starter/tree/main/.claude/skills/test-writerType this inside Codex. $skill-installer <name> installs a curated skill from openai/skills. The installer writes to $CODEX_HOME/skills (default ~/.codex/skills). Restart Codex if the skill does not show up.
$ npx skills add hamzafarooq/claude-code-starter --skill test-writer -a codexProject install goes to .agents/skills/; add -g for ~/.codex/skills/.
$ gh skill install hamzafarooq/claude-code-starter test-writer --agent codexProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/hamzafarooq/claude-code-starter.git skills-src && mkdir -p .agents/skills && cp -r skills-src/.claude/skills/test-writer .agents/skills/test-writer && rm -rf skills-srcUse ~/.agents/skills/ instead of .agents/skills for a personal install.
Codex skills documentation · loads skills from .agents/skills/
Install the "test-writer" agent skill from https://github.com/hamzafarooq/claude-code-starter/tree/main/.claude/skills/test-writer into .agents/skills/test-writer/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "test-writer", then confirm the skill loads.Codex copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ npx skills add hamzafarooq/claude-code-starter --skill test-writer -a cursorProject install goes to .agents/skills/; add -g for ~/.cursor/skills/.
$ gh skill install hamzafarooq/claude-code-starter test-writer --agent cursorProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/hamzafarooq/claude-code-starter.git skills-src && mkdir -p .cursor/skills && cp -r skills-src/.claude/skills/test-writer .cursor/skills/test-writer && rm -rf skills-srcUse ~/.cursor/skills/ instead of .cursor/skills for a personal install.
Cursor skills documentation · loads skills from .cursor/skills/, .agents/skills/, .claude/skills/, .codex/skills/
Install the "test-writer" agent skill from https://github.com/hamzafarooq/claude-code-starter/tree/main/.claude/skills/test-writer into .cursor/skills/test-writer/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "test-writer", then confirm the skill loads.Cursor copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ gemini skills install https://github.com/hamzafarooq/claude-code-starter.git --path .claude/skills/test-writer--scope user (default) or --scope workspace; --path is the subfolder of the repo that holds the skill; --consent skips the security confirmation prompt.
$ npx skills add hamzafarooq/claude-code-starter --skill test-writer -a gemini-cliProject install goes to .agents/skills/; add -g for ~/.gemini/skills/.
$ gh skill install hamzafarooq/claude-code-starter test-writer --agent gemini-cliProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/hamzafarooq/claude-code-starter.git skills-src && mkdir -p .gemini/skills && cp -r skills-src/.claude/skills/test-writer .gemini/skills/test-writer && rm -rf skills-srcUse ~/.gemini/skills/ instead of .gemini/skills for a personal install, then run /skills reload.
Gemini CLI skills documentation · loads skills from .gemini/skills/, .agents/skills/
Install the "test-writer" agent skill from https://github.com/hamzafarooq/claude-code-starter/tree/main/.claude/skills/test-writer into .gemini/skills/test-writer/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "test-writer", then confirm the skill loads.Gemini CLI copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ gh skill install hamzafarooq/claude-code-starter test-writerInstalls for Copilot at project scope by default; add --scope user for a personal install. Preview a skill first with gh skill preview. Needs GitHub CLI 2.90.0 or later (public preview).
$ npx skills add hamzafarooq/claude-code-starter --skill test-writer -a github-copilotProject install goes to .agents/skills/; add -g for ~/.copilot/skills/.
$ git clone --depth 1 https://github.com/hamzafarooq/claude-code-starter.git skills-src && mkdir -p .github/skills && cp -r skills-src/.claude/skills/test-writer .github/skills/test-writer && rm -rf skills-srcUse ~/.copilot/skills/ instead of .github/skills for a personal install. Commit .github/skills so cloud agent and code review can use it.
GitHub Copilot skills documentation · loads skills from .github/skills/, .claude/skills/, .agents/skills/
Install the "test-writer" agent skill from https://github.com/hamzafarooq/claude-code-starter/tree/main/.claude/skills/test-writer into .github/skills/test-writer/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "test-writer", then confirm the skill loads.GitHub Copilot copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ npx skills add hamzafarooq/claude-code-starter --skill test-writer -a opencodeOpenCode documents no install command of its own. Project install goes to .agents/skills/; add -g for ~/.config/opencode/skills/.
$ gh skill install hamzafarooq/claude-code-starter test-writer --agent opencodeProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/hamzafarooq/claude-code-starter.git skills-src && mkdir -p .opencode/skills && cp -r skills-src/.claude/skills/test-writer .opencode/skills/test-writer && rm -rf skills-srcUse ~/.config/opencode/skills/ instead of .opencode/skills for a personal install.
OpenCode skills documentation · loads skills from .opencode/skills/, .claude/skills/, .agents/skills/
Install the "test-writer" agent skill from https://github.com/hamzafarooq/claude-code-starter/tree/main/.claude/skills/test-writer into .opencode/skills/test-writer/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "test-writer", then confirm the skill loads.OpenCode copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
Facts
- Skill name
test-writer- GitHub stars
- 145
- Token cost
- ~345 tokens
- SKILL.md length
- 155 words
- Files
- 1
- Skills in repo
- 29
- Repo updated
- First seen
- Licence
- MIT
At a glance
Write unit tests for any function — happy path, edge cases, and error cases.
- The user asks for tests
- Instructions only: no scripts, shell commands, URLs or credentials in SKILL.md
- Wants to add test coverage
- Is practicing TDD
What it does
Test Writer is an agent skill from hamzafarooq/claude-code-starter. Write unit tests for any function — happy path, edge cases, and error cases. Use when the user asks for tests, wants to add test coverage, or is practicing TDD.
Its SKILL.md is about 350 tokens, which your agent loads only when the skill is triggered. It is a single SKILL.md file with no bundled scripts.
It sits in Testing & QA, covering Unit testing, Test coverage and Test-driven development. The licence is MIT.
When your agent uses it
- The user asks for tests
- Wants to add test coverage
- Is practicing TDD
Example prompts
- “/test-writer”
What it can do on your machine
Read from SKILL.md and the folder at commit 172c531. It shows what the files ask for, not the result of running them.
Tool permissions
Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.
From allowed-tools in the SKILL.md frontmatter.
Runs code
No scripts in the folder and no shell commands in SKILL.md (its code samples are language).
From the folder's file list and the shell code blocks in SKILL.md.
Network
No URLs in SKILL.md.
From URLs in SKILL.md, links to its own repository left out.
Credentials
Names no API keys, tokens, secrets or passwords.
From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.
Context cost
Test Writer loads about 345 tokens when it runs. Until then it costs about 43 tokens; SKILL.md has 155 words of instructions outside code blocks.
Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.
Safety
Auto-check passed
The automated check found no risky patterns in SKILL.md.
Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.
SKILL.md
The full file from hamzafarooq/claude-code-starter at commit 172c531, republished under its MIT licence (© hamzafarooq). 155 words, ~345 tokens.
Download SKILL.mdSave it as
.claude/skills/test-writer/SKILL.md (or your agent's skills folder).- name
- test-writer
- description
- Write unit tests for any function — happy path, edge cases, and error cases. Use when the user asks for tests, wants to add test coverage, or is practicing TDD.
Ask the user to share the function or code they want tests for.
Then write tests covering:
Tests for [functionName]
Testing framework: [detect from package.json — Jest, Vitest, pytest, etc. Ask if unclear]
Happy path
Test the expected behavior with valid inputs. One test per meaningful variation.
test('returns [expected] when given [input]', () => {
// arrange
// act
// assert
})Edge cases
Tests for boundary conditions and unusual but valid inputs:
- Empty input (empty string, empty array, 0)
- Single item
- Maximum size or value
- Special characters (if string input)
Error cases
Tests that verify the function fails correctly:
- Invalid input types
- Null/undefined inputs
- Inputs that should trigger error handling
Mock requirements
List any external dependencies (API calls, database queries, file system) that need mocking, with example mock setup.
Coverage target: Aim for all branches, not just lines. Flag any branch that is difficult to test and explain why.
Write tests that read like documentation — the test name should be a sentence explaining what the function does in that scenario.
© hamzafarooq, MIT. Rendered from Markdown: HTML in the file is shown as text, images as links, and headings moved down two levels. Raw file
Files
Just SKILL.md in .claude/skills/test-writer of hamzafarooq/claude-code-starter.
Open the folder on GitHubat commit 172c531
Compare with similar skills
Test Writer next to the 5 skills that share the most tags, products or categories with it. Stars are the repository's; “used in” counts other GitHub owners with a copy.
| Skill | Stars | Used in | Tokens | Auto-check | Licence | Repo updated |
|---|---|---|---|---|---|---|
| Test Writer this skillhamzafarooq/claude-code-starter | 145 | — | ~345 | Automated safety check: Pass | MIT | |
| Test Experteinverne/dotfiles | 121 | — | ~2.3k | Automated safety check: Pass | GPL-3.0 | |
| Test Coveragescott-fryxell/brayness | 124 | — | ~1.6k | Automated safety check: Pass | MIT | |
| TDD Guidealirezarezvani/claude-skills | 28k | — | ~3.4k | Automated safety check: Pass | MIT | |
| TDD GuideLeoYeAI/openclaw-master-skills | 2.2k | — | ~1.4k | Automated safety check: Pass | MIT | |
| Discover Testingrand/cc-polymath | 181 | — | ~513 | Automated safety check: Pass | MIT |
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Categories
Questions about Test Writer
What does Test Writer do?
Write unit tests for any function — happy path, edge cases, and error cases. Test Writer is an agent skill from hamzafarooq/claude-code-starter. Write unit tests for any function — happy path, edge cases, and error cases.
When should I use Test Writer?
Test Writer fits situations like: the user asks for tests; wants to add test coverage; is practicing TDD.
How do I install Test Writer in Claude Code?
Run `npx skills add hamzafarooq/claude-code-starter --skill test-writer -a claude-code`. Or copy the skill folder (.claude/skills/test-writer in hamzafarooq/claude-code-starter) into .claude/skills/test-writer in your project. Claude Code loads it when a task matches its description.
How do I install Test Writer in Codex?
Run `npx skills add hamzafarooq/claude-code-starter --skill test-writer -a codex`. Or copy the skill folder (.claude/skills/test-writer in hamzafarooq/claude-code-starter) into .agents/skills/test-writer in your project. Codex loads it when a task matches its description.
Can I use Test Writer in Cursor, Gemini CLI or GitHub Copilot?
Cursor, Gemini CLI, GitHub Copilot and OpenCode also load SKILL.md folders. With the skills CLI, run `npx skills add hamzafarooq/claude-code-starter --skill test-writer -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/test-writer, .gemini/skills/test-writer, .github/skills/test-writer and .opencode/skills/test-writer in your project.
What does Test Writer need to run?
SKILL.md names no scripts, command-line tools or credentials: Test Writer is instructions for the agent only.
Does Test Writer access the network?
SKILL.md contains no URLs. Any network use would come from the scripts or tools the agent runs. This is read from the text; nothing was executed.
Is Test Writer safe to install?
Our automated static check of SKILL.md found no risky patterns, such as piping downloads into a shell, reading credential files or hidden Unicode. It is not a guarantee. Review the folder before installing.
What licence does Test Writer use?
Test Writer is published under the MIT licence (the repository's licence). It allows redistribution, so the full SKILL.md is shown on this page.
How many tokens does Test Writer use?
About 345 tokens (SKILL.md is roughly 1.4k characters). Agents keep only the skill's name and description in context until a task matches; then they load SKILL.md in full.
What are the alternatives to Test Writer?
Skills that share tags, products or a category with Test Writer: Test Expert (einverne/dotfiles, 121 stars), Test Coverage (scott-fryxell/brayness, 124 stars), TDD Guide (alirezarezvani/claude-skills, 28k stars) and TDD Guide (LeoYeAI/openclaw-master-skills, 2.2k stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.
Who maintains Test Writer?
hamzafarooq (a GitHub user) maintains it in hamzafarooq/claude-code-starter, which has 145 GitHub stars. The repository holds 29 skills in this directory. The repository was last updated on September 13, 2026.
Source: hamzafarooq/claude-code-starter on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.