Designing Tests
CloudAI-X/claude-workflow-v2
Designs and implements testing strategies for any codebase. An agent skill from CloudAI-X/claude-workflow-v2.
A skill your agent uses when writing, reviewing, or keeping a unit/integration test (Jest, Vitest, xUnit).
Install Test Behavior Not Implementation
$ npx skills add fmflurry/settings-opencode --skill test-behavior-not-implementation -a claude-codeProject install by default; add -g for ~/.claude/skills/.
$ gh skill install fmflurry/settings-opencode test-behavior-not-implementation --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/fmflurry/settings-opencode.git skills-src && mkdir -p .claude/skills && cp -r skills-src/skills/test-behavior-not-implementation .claude/skills/test-behavior-not-implementation && 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-behavior-not-implementation" agent skill from https://github.com/fmflurry/settings-opencode/tree/master/skills/test-behavior-not-implementation into .claude/skills/test-behavior-not-implementation/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "test-behavior-not-implementation", 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/fmflurry/settings-opencode/tree/master/skills/test-behavior-not-implementationType 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 fmflurry/settings-opencode --skill test-behavior-not-implementation -a codexProject install goes to .agents/skills/; add -g for ~/.codex/skills/.
$ gh skill install fmflurry/settings-opencode test-behavior-not-implementation --agent codexProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/fmflurry/settings-opencode.git skills-src && mkdir -p .agents/skills && cp -r skills-src/skills/test-behavior-not-implementation .agents/skills/test-behavior-not-implementation && 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-behavior-not-implementation" agent skill from https://github.com/fmflurry/settings-opencode/tree/master/skills/test-behavior-not-implementation into .agents/skills/test-behavior-not-implementation/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "test-behavior-not-implementation", 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 fmflurry/settings-opencode --skill test-behavior-not-implementation -a cursorProject install goes to .agents/skills/; add -g for ~/.cursor/skills/.
$ gh skill install fmflurry/settings-opencode test-behavior-not-implementation --agent cursorProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/fmflurry/settings-opencode.git skills-src && mkdir -p .cursor/skills && cp -r skills-src/skills/test-behavior-not-implementation .cursor/skills/test-behavior-not-implementation && 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-behavior-not-implementation" agent skill from https://github.com/fmflurry/settings-opencode/tree/master/skills/test-behavior-not-implementation into .cursor/skills/test-behavior-not-implementation/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "test-behavior-not-implementation", 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/fmflurry/settings-opencode.git --path skills/test-behavior-not-implementation--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 fmflurry/settings-opencode --skill test-behavior-not-implementation -a gemini-cliProject install goes to .agents/skills/; add -g for ~/.gemini/skills/.
$ gh skill install fmflurry/settings-opencode test-behavior-not-implementation --agent gemini-cliProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/fmflurry/settings-opencode.git skills-src && mkdir -p .gemini/skills && cp -r skills-src/skills/test-behavior-not-implementation .gemini/skills/test-behavior-not-implementation && 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-behavior-not-implementation" agent skill from https://github.com/fmflurry/settings-opencode/tree/master/skills/test-behavior-not-implementation into .gemini/skills/test-behavior-not-implementation/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "test-behavior-not-implementation", 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 fmflurry/settings-opencode test-behavior-not-implementationInstalls 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 fmflurry/settings-opencode --skill test-behavior-not-implementation -a github-copilotProject install goes to .agents/skills/; add -g for ~/.copilot/skills/.
$ git clone --depth 1 https://github.com/fmflurry/settings-opencode.git skills-src && mkdir -p .github/skills && cp -r skills-src/skills/test-behavior-not-implementation .github/skills/test-behavior-not-implementation && 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-behavior-not-implementation" agent skill from https://github.com/fmflurry/settings-opencode/tree/master/skills/test-behavior-not-implementation into .github/skills/test-behavior-not-implementation/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "test-behavior-not-implementation", 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 fmflurry/settings-opencode --skill test-behavior-not-implementation -a opencodeOpenCode documents no install command of its own. Project install goes to .agents/skills/; add -g for ~/.config/opencode/skills/.
$ gh skill install fmflurry/settings-opencode test-behavior-not-implementation --agent opencodeProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/fmflurry/settings-opencode.git skills-src && mkdir -p .opencode/skills && cp -r skills-src/skills/test-behavior-not-implementation .opencode/skills/test-behavior-not-implementation && 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-behavior-not-implementation" agent skill from https://github.com/fmflurry/settings-opencode/tree/master/skills/test-behavior-not-implementation into .opencode/skills/test-behavior-not-implementation/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "test-behavior-not-implementation", 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-behavior-not-implementation- GitHub stars
- 171
- Token cost
- ~736 tokens
- SKILL.md length
- 341 words
- Files
- 1
- Skills in repo
- 20
- Repo updated
- First seen
- Licence
- MIT
At a glance
A skill your agent uses when writing, reviewing, or keeping a unit/integration test (Jest, Vitest, xUnit).
- Keeping a unit/integration test (Jest
- SKILL.md covers Five Weak Shapes, The Fix and Keep These
- Instructions only: no scripts, shell commands, URLs or credentials in SKILL.md
- Tasks that involve Unit testing
What it does
Test Behavior Not Implementation is an agent skill from fmflurry/settings-opencode. Use when writing, reviewing, or keeping a unit/integration test (Jest, Vitest, xUnit). Detects tests that cannot fail for a defect: mock-only, weak, self-referential, constant-pin, fixture-asserts-fixture.
Its SKILL.md is about 740 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 and Integration testing. It works with Jest and Vitest. The repository describes itself as: Custom OpenCode settings. The licence is MIT.
When your agent uses it
- Keeping a unit/integration test (Jest
- Tasks that involve Unit testing
- Tasks that involve Integration testing
Example prompts
- “/test-behavior-not-implementation”
What it can do on your machine
Read from SKILL.md and the folder at commit 0e6c33c. 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
Test Behavior Not Implementation loads about 736 tokens when it runs. Until then it costs about 60 tokens; SKILL.md has 341 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 fmflurry/settings-opencode at commit 0e6c33c, republished under its MIT licence (© fmflurry). 341 words, ~736 tokens.
Download SKILL.mdSave it as
.claude/skills/test-behavior-not-implementation/SKILL.md (or your agent's skills folder).- name
- test-behavior-not-implementation
- description
- Use when writing, reviewing, or keeping a unit/integration test (Jest, Vitest, xUnit). Detects tests that cannot fail for a defect: mock-only, weak, self-referential, constant-pin, fixture-asserts-fixture.
Test Behavior, Not Implementation
A test calls the code the way its users do and asserts the result they observe against a literal expected value. A test that asserts which calls the code made, or restates a constant the code contains, does neither.
The check: before you keep a test, ask whether it would still pass if every function it imports returned undefined. If yes, it observes no behavior and cannot fail for a defect. Rewrite the assertion or delete the test.
Why: A test that cannot fail for a defect costs CI time and review attention and catches nothing. A constant pin also fails when someone edits the constant or the prompt it restates, so it prevents that edit.
Five Weak Shapes
- Weak or no assertion. No
expect, or onlytoBeDefined,toBeTruthy,not.toThrow,toBeInstanceOf,toBeGreaterThan(0). - Mock or absence only. Only
toHaveBeenCalled,not.toHaveBeenCalled,toHaveBeenCalledTimes(N),toBeUndefined,toEqual([]),toHaveLength(0),not.toBe(wrongValue). - Self-referential. The expected value comes from the code under test:
expect(f(a)).toBe(f(a)),expect(parsed.url).toBe(buildUrl(...)). - Constant pin. The assertion restates a hand-maintained constant:
expect(LIMITS.maxTools).toBe(8),expect(PROMPT).toContain("You are"). - Fixture asserts fixture. The assertion reads data the test built in
beforeEach, and the subject never runs inside the test body.
The Fix
For mock-only: Assert the payload the mock received or the state after the call, not that it was called.
// WRONG
expect(handleClick).toHaveBeenCalledTimes(1)
// RIGHT
expect(handleClick).toHaveBeenCalledWith('item-42')For weak assertion: Call the subject inside the test body with one concrete input and assert the literal output or the observable effect.
// WRONG
expect(slugify("Hello")).toBeDefined()
// RIGHT
expect(slugify("Hello, World!")).toBe("hello-world")For self-referential: Test the mechanism that reads it with one concrete input instead of calling the same function twice.
For constant pin: Test the mechanism that reads the constant, not the constant value itself.
For fixture asserts fixture: Actually call the subject under test with the fixture as input and assert the output.
When no such assertion exists, delete the test.
Keep These
- A test of a relation across a table's rows (a key present in two tables, a parent that exists).
- A compile-time check in a
*.test-d.tsfile. - xUnit:
Assert.NotNull(result)alone or baremock.Verify(...)are weak — assert the returned value or persisted state instead.
© fmflurry, 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 skills/test-behavior-not-implementation of fmflurry/settings-opencode.
Open the folder on GitHubat commit 0e6c33c
Compare with similar skills
Test Behavior Not Implementation 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 Behavior Not Implementation this skillfmflurry/settings-opencode | 171 | — | ~736 | Automated safety check: Pass | MIT | |
| Designing TestsCloudAI-X/claude-workflow-v2 | 1.4k | 1 repos | ~1.5k | Automated safety check: Pass | MIT | |
| Tsed Testingtsedio/tsed | 3.1k | — | ~2k | Automated safety check: Pass | MIT | |
| Test Writing WorkflowiOfficeAI/AionUi | 33k | 1 repos | ~1.2k | Automated safety check: Pass | Apache-2.0 | |
| Vitestsupabase/supabase | 111k | 12 repos | ~1.1k | Automated safety check: Pass | Apache-2.0 | |
| Test GuardamElnagdy/guard-skills | 1.3k | 2 repos | ~2.1k | Automated safety check: Pass | MIT |
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Related
Categories
Questions about Test Behavior Not Implementation
What does Test Behavior Not Implementation do?
A skill your agent uses when writing, reviewing, or keeping a unit/integration test (Jest, Vitest, xUnit). Test Behavior Not Implementation is an agent skill from fmflurry/settings-opencode. Use when writing, reviewing, or keeping a unit/integration test (Jest, Vitest, xUnit).
When should I use Test Behavior Not Implementation?
Test Behavior Not Implementation fits situations like: keeping a unit/integration test (Jest; tasks that involve Unit testing; tasks that involve Integration testing.
How do I install Test Behavior Not Implementation in Claude Code?
Run `npx skills add fmflurry/settings-opencode --skill test-behavior-not-implementation -a claude-code`. Or copy the skill folder (skills/test-behavior-not-implementation in fmflurry/settings-opencode) into .claude/skills/test-behavior-not-implementation in your project. Claude Code loads it when a task matches its description.
How do I install Test Behavior Not Implementation in Codex?
Run `npx skills add fmflurry/settings-opencode --skill test-behavior-not-implementation -a codex`. Or copy the skill folder (skills/test-behavior-not-implementation in fmflurry/settings-opencode) into .agents/skills/test-behavior-not-implementation in your project. Codex loads it when a task matches its description.
Can I use Test Behavior Not Implementation 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 fmflurry/settings-opencode --skill test-behavior-not-implementation -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-behavior-not-implementation, .gemini/skills/test-behavior-not-implementation, .github/skills/test-behavior-not-implementation and .opencode/skills/test-behavior-not-implementation in your project.
What does Test Behavior Not Implementation need to run?
SKILL.md names no scripts, command-line tools or credentials: Test Behavior Not Implementation is instructions for the agent only.
Does Test Behavior Not Implementation 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 Behavior Not Implementation 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 Behavior Not Implementation use?
Test Behavior Not Implementation 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 Behavior Not Implementation use?
About 736 tokens (SKILL.md is roughly 2.9k 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 Behavior Not Implementation?
Skills that share tags, products or a category with Test Behavior Not Implementation: Designing Tests (CloudAI-X/claude-workflow-v2, 1.4k stars), Tsed Testing (tsedio/tsed, 3.1k stars), Test Writing Workflow (iOfficeAI/AionUi, 33k stars) and Vitest (supabase/supabase, 111k stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.
Who maintains Test Behavior Not Implementation?
fmflurry (a GitHub user) maintains it in fmflurry/settings-opencode, which has 171 GitHub stars. The repository holds 20 skills in this directory. The repository was last updated on October 7, 2026.
Source: fmflurry/settings-opencode on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.