Impeccable
bestofjs/bestofjs
A skill your agent uses when the user wants to design, redesign, shape, critique, audit, polish, clarify, distill, harden, optimize, adapt, animate, colorize, extract, or otherwise improve a…
Write and edit test files that model real user flows. An agent skill from cashew-labs/libretto.
Install Writing Tests
$ npx skills add cashew-labs/libretto --skill writing-tests -a claude-codeProject install by default; add -g for ~/.claude/skills/.
$ gh skill install cashew-labs/libretto writing-tests --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/cashew-labs/libretto.git skills-src && mkdir -p .claude/skills && cp -r skills-src/.agents/skills/writing-tests .claude/skills/writing-tests && 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 "writing-tests" agent skill from https://github.com/cashew-labs/libretto/tree/main/.agents/skills/writing-tests into .claude/skills/writing-tests/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "writing-tests", 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/cashew-labs/libretto/tree/main/.agents/skills/writing-testsType 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 cashew-labs/libretto --skill writing-tests -a codexProject install goes to .agents/skills/; add -g for ~/.codex/skills/.
$ gh skill install cashew-labs/libretto writing-tests --agent codexProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/cashew-labs/libretto.git skills-src && mkdir -p .agents/skills && cp -r skills-src/.agents/skills/writing-tests .agents/skills/writing-tests && rm -rf skills-srcUse ~/.agents/skills/ instead of .agents/skills for a personal install.
Codex skills documentation · loads skills from .agents/skills/
Install the "writing-tests" agent skill from https://github.com/cashew-labs/libretto/tree/main/.agents/skills/writing-tests into .agents/skills/writing-tests/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "writing-tests", 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 cashew-labs/libretto --skill writing-tests -a cursorProject install goes to .agents/skills/; add -g for ~/.cursor/skills/.
$ gh skill install cashew-labs/libretto writing-tests --agent cursorProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/cashew-labs/libretto.git skills-src && mkdir -p .cursor/skills && cp -r skills-src/.agents/skills/writing-tests .cursor/skills/writing-tests && 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 "writing-tests" agent skill from https://github.com/cashew-labs/libretto/tree/main/.agents/skills/writing-tests into .cursor/skills/writing-tests/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "writing-tests", 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/cashew-labs/libretto.git --path .agents/skills/writing-tests--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 cashew-labs/libretto --skill writing-tests -a gemini-cliProject install goes to .agents/skills/; add -g for ~/.gemini/skills/.
$ gh skill install cashew-labs/libretto writing-tests --agent gemini-cliProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/cashew-labs/libretto.git skills-src && mkdir -p .gemini/skills && cp -r skills-src/.agents/skills/writing-tests .gemini/skills/writing-tests && 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 "writing-tests" agent skill from https://github.com/cashew-labs/libretto/tree/main/.agents/skills/writing-tests into .gemini/skills/writing-tests/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "writing-tests", 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 cashew-labs/libretto writing-testsInstalls 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 cashew-labs/libretto --skill writing-tests -a github-copilotProject install goes to .agents/skills/; add -g for ~/.copilot/skills/.
$ git clone --depth 1 https://github.com/cashew-labs/libretto.git skills-src && mkdir -p .github/skills && cp -r skills-src/.agents/skills/writing-tests .github/skills/writing-tests && 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 "writing-tests" agent skill from https://github.com/cashew-labs/libretto/tree/main/.agents/skills/writing-tests into .github/skills/writing-tests/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "writing-tests", 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 cashew-labs/libretto --skill writing-tests -a opencodeOpenCode documents no install command of its own. Project install goes to .agents/skills/; add -g for ~/.config/opencode/skills/.
$ gh skill install cashew-labs/libretto writing-tests --agent opencodeProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/cashew-labs/libretto.git skills-src && mkdir -p .opencode/skills && cp -r skills-src/.agents/skills/writing-tests .opencode/skills/writing-tests && 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 "writing-tests" agent skill from https://github.com/cashew-labs/libretto/tree/main/.agents/skills/writing-tests into .opencode/skills/writing-tests/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "writing-tests", 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
writing-tests- GitHub stars
- 904
- Token cost
- ~535 tokens
- SKILL.md length
- 274 words
- Files
- 1
- Skills in repo
- 21
- Repo updated
- First seen
- Licence
- MIT
At a glance
Write and edit test files that model real user flows. An agent skill from cashew-labs/libretto.
- Works in 4 steps: Match the user's interface exactly → Keep tests verbose and concrete → One flow per test → …
- Reviewing test files
- SKILL.md covers Core Principle: Tests Are User… and Rules
- Instructions only: no scripts, shell commands, URLs or credentials in SKILL.md
What it does
Writing Tests is an agent skill from cashew-labs/libretto. Write and edit test files that model real user flows. Use when creating, modifying, or reviewing test files.
Its SKILL.md is about 540 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 Frontend & Design, covering UX design. The repository describes itself as: The AI toolkit for building reliable browser automations. The licence is MIT.
When your agent uses it
- Reviewing test files
- Tasks that involve UX design
Example prompts
- “/writing-tests”
Workflow steps
4 steps, taken from the step headings in SKILL.md.
What it can do on your machine
Read from SKILL.md and the folder at commit 41ab782. 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 typescript).
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
Writing Tests loads about 535 tokens when it runs. Until then it costs about 31 tokens; SKILL.md has 274 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 cashew-labs/libretto at commit 41ab782, republished under its MIT licence (© cashew-labs). 274 words, ~535 tokens.
Download SKILL.mdSave it as
.claude/skills/writing-tests/SKILL.md (or your agent's skills folder).- name
- writing-tests
- description
- Write and edit test files that model real user flows. Use when creating, modifying, or reviewing test files.
Writing Tests
Core Principle: Tests Are User Flows
Each test should represent a single, concrete flow that a real user would follow when interacting with the system. Write tests at the same abstraction level as the user experiences the system.
Rules
1. Match the user's interface exactly
The test should call the system the same way a user would. If the system is a CLI, the test should invoke the CLI with argument strings. If it's a library, the test should call the public API. Don't wrap the interface in test-specific helpers that hide what's actually happening.
Good — the test reads like what a user would do:
const result = await librettoCli("setup --skip-browsers");
expect(result.exitCode).toBe(0);
const result2 = await librettoCli("--help");
expect(result2.stdout).toContain("Usage:");Bad — extra abstraction obscures the actual interaction:
const result = await setupWithDefaults(); // hides the real CLI invocation
assertSuccess(result); // hides what "success" means2. Keep tests verbose and concrete
Don't introduce helpers for brevity. The value of a test is that you can read it top-to-bottom and understand exactly what's happening. Repetition across tests is fine — each test should be self-contained and readable on its own.
3. One flow per test
Each test should exercise one coherent user scenario from setup through assertion. Don't combine unrelated flows into a single test, and don't split one logical flow across multiple tests.
4. Tests form a behavioral hull
The full set of tests for a system should cover the sufficiently complete set of flows a user might follow. Think about:
- The happy path for each major feature
- Edge cases a user would realistically hit
- Error cases and what the user sees when things go wrong
When adding a new feature, add tests that cover the new user flows it introduces. When fixing a bug, add a test that reproduces the flow where the bug occurred.
© cashew-labs, 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 .agents/skills/writing-tests of cashew-labs/libretto.
Open the folder on GitHubat commit 41ab782
Compare with similar skills
Writing Tests 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 |
|---|---|---|---|---|---|---|
| Writing Tests this skillcashew-labs/libretto | 904 | — | ~535 | Automated safety check: Pass | MIT | |
| Impeccablebestofjs/bestofjs | 3.1k | 26 repos | ~2.6k | Automated safety check: Pass | MIT | |
| Interface Design for Dashboards and Appsholaboss-ai/holaOS | 11k | 3 repos | ~6k | Automated safety check: Pass | MIT | |
| Animategrowupanand/ConvoForm | 102 | 6 repos | ~1.9k | Automated safety check: Pass | Apache-2.0 | |
| Migrate Content Iadocker/docs | 4.7k | — | ~5.1k | Automated safety check: Pass | Apache-2.0 | |
| UX WalkthroughXiaoMi/hiui | 879 | — | ~1.3k | Automated safety check: Pass | MIT |
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Related
Categories
Questions about Writing Tests
What does Writing Tests do?
Write and edit test files that model real user flows. An agent skill from cashew-labs/libretto. Writing Tests is an agent skill from cashew-labs/libretto. Write and edit test files that model real user flows.
When should I use Writing Tests?
Writing Tests fits situations like: reviewing test files; tasks that involve UX design.
How do I install Writing Tests in Claude Code?
Run `npx skills add cashew-labs/libretto --skill writing-tests -a claude-code`. Or copy the skill folder (.agents/skills/writing-tests in cashew-labs/libretto) into .claude/skills/writing-tests in your project. Claude Code loads it when a task matches its description.
How do I install Writing Tests in Codex?
Run `npx skills add cashew-labs/libretto --skill writing-tests -a codex`. Or copy the skill folder (.agents/skills/writing-tests in cashew-labs/libretto) into .agents/skills/writing-tests in your project. Codex loads it when a task matches its description.
Can I use Writing Tests 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 cashew-labs/libretto --skill writing-tests -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/writing-tests, .gemini/skills/writing-tests, .github/skills/writing-tests and .opencode/skills/writing-tests in your project.
What does Writing Tests need to run?
SKILL.md names no scripts, command-line tools or credentials: Writing Tests is instructions for the agent only.
Does Writing Tests 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 Writing Tests 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 Writing Tests use?
Writing Tests 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 Writing Tests use?
About 535 tokens (SKILL.md is roughly 2.1k 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 Writing Tests?
Skills that share tags, products or a category with Writing Tests: Impeccable (bestofjs/bestofjs, 3.1k stars), Interface Design for Dashboards and Apps (holaboss-ai/holaOS, 11k stars), Animate (growupanand/ConvoForm, 102 stars) and Migrate Content Ia (docker/docs, 4.7k stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.
Who maintains Writing Tests?
cashew-labs (a GitHub organization) maintains it in cashew-labs/libretto, which has 904 GitHub stars. The repository holds 21 skills in this directory. The repository was last updated on August 21, 2026.
Source: cashew-labs/libretto on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.