Agent skill

Test Generation

Generate comprehensive test suites for existing code. An agent skill from agulli/atlas-agents.

MITAuto-check passedTesting & QA

Install Test Generation

skills CLI

$ npx skills add agulli/atlas-agents --skill test-generation -a claude-code

Project install by default; add -g for ~/.claude/skills/.

GitHub CLI

$ gh skill install agulli/atlas-agents test-generation --agent claude-code

Project scope by default; add --scope user for a personal install. Needs GitHub CLI 2.90.0 or later (public preview).

Manual copy

$ git clone --depth 1 https://github.com/agulli/atlas-agents.git skills-src && mkdir -p .claude/skills && cp -r skills-src/ch09_agent_skills/skills/test-generation .claude/skills/test-generation && rm -rf skills-src

Use ~/.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/

Paste into Claude Code

Install the "test-generation" agent skill from https://github.com/agulli/atlas-agents/tree/main/ch09_agent_skills/skills/test-generation into .claude/skills/test-generation/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "test-generation", 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

$skill-installer install https://github.com/agulli/atlas-agents/tree/main/ch09_agent_skills/skills/test-generation

Type 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.

skills CLI

$ npx skills add agulli/atlas-agents --skill test-generation -a codex

Project install goes to .agents/skills/; add -g for ~/.codex/skills/.

GitHub CLI

$ gh skill install agulli/atlas-agents test-generation --agent codex

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/agulli/atlas-agents.git skills-src && mkdir -p .agents/skills && cp -r skills-src/ch09_agent_skills/skills/test-generation .agents/skills/test-generation && rm -rf skills-src

Use ~/.agents/skills/ instead of .agents/skills for a personal install.

Codex skills documentation · loads skills from .agents/skills/

Paste into Codex

Install the "test-generation" agent skill from https://github.com/agulli/atlas-agents/tree/main/ch09_agent_skills/skills/test-generation into .agents/skills/test-generation/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "test-generation", 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.

skills CLI

$ npx skills add agulli/atlas-agents --skill test-generation -a cursor

Project install goes to .agents/skills/; add -g for ~/.cursor/skills/.

GitHub CLI

$ gh skill install agulli/atlas-agents test-generation --agent cursor

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/agulli/atlas-agents.git skills-src && mkdir -p .cursor/skills && cp -r skills-src/ch09_agent_skills/skills/test-generation .cursor/skills/test-generation && rm -rf skills-src

Use ~/.cursor/skills/ instead of .cursor/skills for a personal install.

Cursor skills documentation · loads skills from .cursor/skills/, .agents/skills/, .claude/skills/, .codex/skills/

Paste into Cursor

Install the "test-generation" agent skill from https://github.com/agulli/atlas-agents/tree/main/ch09_agent_skills/skills/test-generation into .cursor/skills/test-generation/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "test-generation", 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

$ gemini skills install https://github.com/agulli/atlas-agents.git --path ch09_agent_skills/skills/test-generation

--scope user (default) or --scope workspace; --path is the subfolder of the repo that holds the skill; --consent skips the security confirmation prompt.

skills CLI

$ npx skills add agulli/atlas-agents --skill test-generation -a gemini-cli

Project install goes to .agents/skills/; add -g for ~/.gemini/skills/.

GitHub CLI

$ gh skill install agulli/atlas-agents test-generation --agent gemini-cli

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/agulli/atlas-agents.git skills-src && mkdir -p .gemini/skills && cp -r skills-src/ch09_agent_skills/skills/test-generation .gemini/skills/test-generation && rm -rf skills-src

Use ~/.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/

Paste into Gemini CLI

Install the "test-generation" agent skill from https://github.com/agulli/atlas-agents/tree/main/ch09_agent_skills/skills/test-generation into .gemini/skills/test-generation/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "test-generation", 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.

GitHub CLI

$ gh skill install agulli/atlas-agents test-generation

Installs 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).

skills CLI

$ npx skills add agulli/atlas-agents --skill test-generation -a github-copilot

Project install goes to .agents/skills/; add -g for ~/.copilot/skills/.

Manual copy

$ git clone --depth 1 https://github.com/agulli/atlas-agents.git skills-src && mkdir -p .github/skills && cp -r skills-src/ch09_agent_skills/skills/test-generation .github/skills/test-generation && rm -rf skills-src

Use ~/.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/

Paste into GitHub Copilot

Install the "test-generation" agent skill from https://github.com/agulli/atlas-agents/tree/main/ch09_agent_skills/skills/test-generation into .github/skills/test-generation/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "test-generation", 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.

skills CLI

$ npx skills add agulli/atlas-agents --skill test-generation -a opencode

OpenCode documents no install command of its own. Project install goes to .agents/skills/; add -g for ~/.config/opencode/skills/.

GitHub CLI

$ gh skill install agulli/atlas-agents test-generation --agent opencode

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/agulli/atlas-agents.git skills-src && mkdir -p .opencode/skills && cp -r skills-src/ch09_agent_skills/skills/test-generation .opencode/skills/test-generation && rm -rf skills-src

Use ~/.config/opencode/skills/ instead of .opencode/skills for a personal install.

OpenCode skills documentation · loads skills from .opencode/skills/, .claude/skills/, .agents/skills/

Paste into OpenCode

Install the "test-generation" agent skill from https://github.com/agulli/atlas-agents/tree/main/ch09_agent_skills/skills/test-generation into .opencode/skills/test-generation/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "test-generation", 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-generation
GitHub stars: 579
Token cost: ~598 tokens
SKILL.md length: 238 words
Files: 1
Skills in repo: 12
Repo updated: Jul 17, 2026
First seen: Oct 7, 2026
Licence: MIT

At a glance

Generate comprehensive test suites for existing code. An agent skill from agulli/atlas-agents.

Works in 6 steps: Read the source code. Load every… → Identify the test framework. Check for → Categorize test types needed → …
Asked to write tests
SKILL.md covers Process, Rationalizations and Verification
Instructions only: no scripts, shell commands, URLs or credentials in SKILL.md

What it does

Test Generation is an agent skill from agulli/atlas-agents. Generate comprehensive test suites for existing code. Use when asked to write tests, add test coverage, create unit tests, or build integration tests.

Its SKILL.md is about 600 tokens, which your agent loads only when the skill is triggered. It is a single SKILL.md file with no bundled scripts. Compatibility notes: Requires pytest (Python) or vitest/jest (Node.js)

It sits in Testing & QA, covering Test generation, Unit testing and Integration testing. It works with pytest and Vitest. The licence is MIT.

When your agent uses it

Asked to write tests
Add test coverage
Create unit tests
Build integration tests

Example prompts

“/test-generation”

Requirements

Python 3
Node.js
Compatibility (from SKILL.md): Requires pytest (Python) or vitest/jest (Node.js)

Workflow steps

6 steps, taken from the first numbered list in SKILL.md.

Read the source code. Load every function and class under test. Do not write tests from a summary or description — you must see the…
Identify the test framework. Check for
Categorize test types needed
Write tests following the AAA pattern
Name tests descriptively. The test name should describe the scenario and expected outcome
Run the tests. Execute the full test suite and confirm all tests pass. If any fail, fix the test (not the source code) unless you discover…

What it can do on your machine

Read from SKILL.md and the folder at commit 2b21998. 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 python).
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.
Compatibility
Requires pytest (Python) or vitest/jest (Node.js)
From compatibility in the SKILL.md frontmatter.

Context cost

Test Generation loads about 598 tokens when it runs. Until then it costs about 42 tokens; SKILL.md has 238 words of instructions outside code blocks.

Always · name and description, kept in context so the agent knows when to use it: ~42
When it runs · the whole SKILL.md, loaded when a task matches: ~598

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 agulli/atlas-agents at commit 2b21998, republished under its MIT licence (© agulli). 238 words, ~598 tokens.

Download SKILL.mdSave it as .claude/skills/test-generation/SKILL.md (or your agent's skills folder).

name: test-generation
description: Generate comprehensive test suites for existing code. Use when asked to write tests, add test coverage, create unit tests, or build integration tests.
compatibility: Requires pytest (Python) or vitest/jest (Node.js)
license: MIT

Process

Read the source code. Load every function and class under test. Do not write tests from a summary or description — you must see the implementation.
Identify the test framework. Check for:
- conftest.py or pytest.ini → pytest
- vitest.config.* → Vitest
- jest.config.* → Jest If none are found, default to pytest for Python, Vitest for TypeScript/JavaScript.
Categorize test types needed:
- Happy path: Normal inputs, expected outputs
- Edge cases: Empty inputs, None/null, boundary values, maximum lengths
- Error cases: Invalid inputs that should raise exceptions or return errors
- Integration: Tests that verify multiple components work together

Write tests following the AAA pattern:

python

def test_descriptive_name():
    # Arrange — set up inputs and expected state
    user = create_test_user(name="Alice")
    
    # Act — call the function under test
    result = get_user_greeting(user)
    
    # Assert — verify the output
    assert result == "Hello, Alice!"

Name tests descriptively. The test name should describe the scenario and expected outcome:
- ✅ test_login_rejects_empty_password
- ❌ test_login_2
Run the tests. Execute the full test suite and confirm all tests pass. If any fail, fix the test (not the source code) unless you discover an actual bug.

Rationalizations

Excuse	Rebuttal
"I'll just write happy path tests"	Edge cases are where bugs live. Write at least one edge case per function.
"The function is too simple to test"	Simple functions get refactored. Tests protect against regressions during refactoring.
"I'll add tests later"	You won't. Write them now.
"Mocking everything is fine"	Over-mocking hides integration bugs. Mock external services, not your own code.

Verification

Tests were executed (not just written)
All tests pass
At least one edge case test exists per function
Test names describe the scenario, not just "test_1", "test_2"

Files

Just SKILL.md in ch09_agent_skills/skills/test-generation of agulli/atlas-agents.

Open the folder on GitHubat commit 2b21998

Compare with similar skills

Test Generation 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.

Test Generation compared with similar skills
Skill	Stars	Used in	Tokens	Auto-check	Licence	Repo updated
Test Generation this skillagulli/atlas-agents	579	—	~598	Automated safety check: Pass	MIT	2 mo ago
Designing TestsCloudAI-X/claude-workflow-v2	1.4k	1 repos	~1.5k	Automated safety check: Pass	MIT	yesterday
Write Test389ds/389-ds-base	294	—	~1.8k	Automated safety check: Pass	Custom licence	yesterday
MoAI TDD Workflowmodu-ai/moai-adk	1.2k	—	~3.1k	Automated safety check: Pass	Apache-2.0	today
Testing Livekit Agentslivekit-examples/agent-starter-python	264	1 repos	~1.9k	Automated safety check: Pass	MIT	2 days ago
Test Patternsrohitg00/skillkit	1.5k	—	~1.8k	Automated safety check: Pass	Apache-2.0	4 mo ago

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Questions about Test Generation

What does Test Generation do?

Generate comprehensive test suites for existing code. An agent skill from agulli/atlas-agents. Test Generation is an agent skill from agulli/atlas-agents. Generate comprehensive test suites for existing code.

When should I use Test Generation?

Test Generation fits situations like: asked to write tests; add test coverage; create unit tests; build integration tests.

How do I install Test Generation in Claude Code?

Run `npx skills add agulli/atlas-agents --skill test-generation -a claude-code`. Or copy the skill folder (ch09_agent_skills/skills/test-generation in agulli/atlas-agents) into .claude/skills/test-generation in your project. Claude Code loads it when a task matches its description.

How do I install Test Generation in Codex?

Run `npx skills add agulli/atlas-agents --skill test-generation -a codex`. Or copy the skill folder (ch09_agent_skills/skills/test-generation in agulli/atlas-agents) into .agents/skills/test-generation in your project. Codex loads it when a task matches its description.

Can I use Test Generation 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 agulli/atlas-agents --skill test-generation -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-generation, .gemini/skills/test-generation, .github/skills/test-generation and .opencode/skills/test-generation in your project.

What does Test Generation need to run?

SKILL.md names no scripts, command-line tools or credentials: Test Generation is instructions for the agent only. Our summary lists: Python 3; Node.js. Compatibility (from SKILL.md): Requires pytest (Python) or vitest/jest (Node.js).

Does Test Generation 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 Generation 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 Generation use?

Test Generation is published under the MIT licence (declared in SKILL.md). It allows redistribution, so the full SKILL.md is shown on this page.

How many tokens does Test Generation use?

About 598 tokens (SKILL.md is roughly 2.4k 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 Generation?

Skills that share tags, products or a category with Test Generation: Designing Tests (CloudAI-X/claude-workflow-v2, 1.4k stars), Write Test (389ds/389-ds-base, 294 stars), MoAI TDD Workflow (modu-ai/moai-adk, 1.2k stars) and Testing Livekit Agents (livekit-examples/agent-starter-python, 264 stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.

Who maintains Test Generation?

agulli (a GitHub user) maintains it in agulli/atlas-agents, which has 579 GitHub stars. The repository holds 12 skills in this directory. The repository was last updated on July 17, 2026.

Source: agulli/atlas-agents on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.

Test Generation

Install Test Generation

Facts

At a glance

What it does

When your agent uses it

Example prompts

Requirements

Workflow steps

What it can do on your machine

Tool permissions

Runs code

Network

Credentials

Compatibility

Context cost

Safety

SKILL.md

Process

Rationalizations

Verification

Files

Compare with similar skills

Similar skills

Designing Tests

Write Test

MoAI TDD Workflow

Testing Livekit Agents

Test Patterns

Test Generator

More from agulli/atlas-agents

API Design

Data Pipeline

Database Migration

Deploy Checklist

Documentation Writer

Git Commit

Questions about Test Generation

Install Test Generation

Facts

At a glance

What it does

When your agent uses it

Example prompts

Requirements

Workflow steps

What it can do on your machine

Tool permissions

Runs code

Network

Credentials

Compatibility

Context cost

Safety

SKILL.md

Process

Rationalizations

Verification

Files

Compare with similar skills

Similar skills

More from agulli/atlas-agents

Related

Questions about Test Generation