TDD Workflow
hellangleZ/burn-in-cceverywhere-ralph
A skill your agent uses when writing new features, fixing bugs, or refactoring code.
Collapse test-shaped production boundaries while preserving behavior and coverage.
Install Cohesion Over Testability
$ npx skills add EpicenterHQ/epicenter --skill cohesion-over-testability -a claude-codeProject install by default; add -g for ~/.claude/skills/.
$ gh skill install EpicenterHQ/epicenter cohesion-over-testability --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/EpicenterHQ/epicenter.git skills-src && mkdir -p .claude/skills && cp -r skills-src/.agents/skills/cohesion-over-testability .claude/skills/cohesion-over-testability && 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 "cohesion-over-testability" agent skill from https://github.com/EpicenterHQ/epicenter/tree/main/.agents/skills/cohesion-over-testability into .claude/skills/cohesion-over-testability/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "cohesion-over-testability", 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/EpicenterHQ/epicenter/tree/main/.agents/skills/cohesion-over-testabilityType 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 EpicenterHQ/epicenter --skill cohesion-over-testability -a codexProject install goes to .agents/skills/; add -g for ~/.codex/skills/.
$ gh skill install EpicenterHQ/epicenter cohesion-over-testability --agent codexProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/EpicenterHQ/epicenter.git skills-src && mkdir -p .agents/skills && cp -r skills-src/.agents/skills/cohesion-over-testability .agents/skills/cohesion-over-testability && rm -rf skills-srcUse ~/.agents/skills/ instead of .agents/skills for a personal install.
Codex skills documentation · loads skills from .agents/skills/
Install the "cohesion-over-testability" agent skill from https://github.com/EpicenterHQ/epicenter/tree/main/.agents/skills/cohesion-over-testability into .agents/skills/cohesion-over-testability/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "cohesion-over-testability", 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 EpicenterHQ/epicenter --skill cohesion-over-testability -a cursorProject install goes to .agents/skills/; add -g for ~/.cursor/skills/.
$ gh skill install EpicenterHQ/epicenter cohesion-over-testability --agent cursorProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/EpicenterHQ/epicenter.git skills-src && mkdir -p .cursor/skills && cp -r skills-src/.agents/skills/cohesion-over-testability .cursor/skills/cohesion-over-testability && 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 "cohesion-over-testability" agent skill from https://github.com/EpicenterHQ/epicenter/tree/main/.agents/skills/cohesion-over-testability into .cursor/skills/cohesion-over-testability/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "cohesion-over-testability", 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/EpicenterHQ/epicenter.git --path .agents/skills/cohesion-over-testability--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 EpicenterHQ/epicenter --skill cohesion-over-testability -a gemini-cliProject install goes to .agents/skills/; add -g for ~/.gemini/skills/.
$ gh skill install EpicenterHQ/epicenter cohesion-over-testability --agent gemini-cliProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/EpicenterHQ/epicenter.git skills-src && mkdir -p .gemini/skills && cp -r skills-src/.agents/skills/cohesion-over-testability .gemini/skills/cohesion-over-testability && 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 "cohesion-over-testability" agent skill from https://github.com/EpicenterHQ/epicenter/tree/main/.agents/skills/cohesion-over-testability into .gemini/skills/cohesion-over-testability/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "cohesion-over-testability", 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 EpicenterHQ/epicenter cohesion-over-testabilityInstalls 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 EpicenterHQ/epicenter --skill cohesion-over-testability -a github-copilotProject install goes to .agents/skills/; add -g for ~/.copilot/skills/.
$ git clone --depth 1 https://github.com/EpicenterHQ/epicenter.git skills-src && mkdir -p .github/skills && cp -r skills-src/.agents/skills/cohesion-over-testability .github/skills/cohesion-over-testability && 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 "cohesion-over-testability" agent skill from https://github.com/EpicenterHQ/epicenter/tree/main/.agents/skills/cohesion-over-testability into .github/skills/cohesion-over-testability/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "cohesion-over-testability", 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 EpicenterHQ/epicenter --skill cohesion-over-testability -a opencodeOpenCode documents no install command of its own. Project install goes to .agents/skills/; add -g for ~/.config/opencode/skills/.
$ gh skill install EpicenterHQ/epicenter cohesion-over-testability --agent opencodeProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/EpicenterHQ/epicenter.git skills-src && mkdir -p .opencode/skills && cp -r skills-src/.agents/skills/cohesion-over-testability .opencode/skills/cohesion-over-testability && 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 "cohesion-over-testability" agent skill from https://github.com/EpicenterHQ/epicenter/tree/main/.agents/skills/cohesion-over-testability into .opencode/skills/cohesion-over-testability/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "cohesion-over-testability", 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
cohesion-over-testability- GitHub stars
- 4.8k
- Token cost
- ~2k tokens
- SKILL.md length
- 1,046 words
- Files
- 2 (incl. references)
- Skills in repo
- 65
- Repo updated
- First seen
- Licence
- Custom licence
At a glance
Collapse test-shaped production boundaries while preserving behavior and coverage.
- Works in 3 steps: The split: production code is in two… → The seam: the inner takes injected… → The test: a unit test calls the inner…
- Injected dependency
- SKILL.md covers References, The Signal vs The Reason, The Procedure and When NOT to Inline, plus 3 more sections
- Instructions only: no scripts, shell commands, URLs or credentials in SKILL.md
What it does
Cohesion Over Testability is an agent skill from EpicenterHQ/epicenter. Collapse test-shaped production boundaries while preserving behavior and coverage. Use when a helper, wrapper, injected dependency, or export exists mainly to let a unit test reach internals.
Its SKILL.md is about 2k tokens, which your agent loads only when the skill is triggered. The skill folder holds 2 other files, including reference files (for example `references/sweep-procedure.md`).
It sits in Testing & QA, covering Unit testing. The repository describes itself as: Open-source, local-first apps.
When your agent uses it
- Injected dependency
- Export exists mainly to let a unit test reach internals
Example prompts
- “/cohesion-over-testability”
Workflow steps
3 steps, taken from the first numbered list in SKILL.md.
- The split: production code is in two pieces.
- The seam: the inner takes injected dependencies.
- The test: a unit test calls the inner with fakes.
What it can do on your machine
Read from SKILL.md and the folder at commit 9cc65c3. 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 bash).
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
Cohesion Over Testability loads about 2k tokens when it runs, and up to ~4.4k if it reads all its reference files. Until then it costs about 54 tokens; SKILL.md has 1,046 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
Its licence (Custom licence) doesn't allow us to republish the file, so here is its outline and opening line. It has 1,046 words (~2,048 tokens).
“A unit test is supposed to verify production code. Sometimes the relationship inverts: the test reaches for an invariant the natural API won't surface, so the production code is split into a "pure inner" and a "thin outer", with the…”
- name
- cohesion-over-testability
- metadata.author
- epicenter
- metadata.version
- 1.0
Files
SKILL.md and 1 other file (references) in .agents/skills/cohesion-over-testability of EpicenterHQ/epicenter.
- SKILL.md
- references/sweep-procedure.md
Open the folder on GitHubat commit 9cc65c3
Compare with similar skills
Cohesion Over Testability 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 |
|---|---|---|---|---|---|---|
| Cohesion Over Testability this skillEpicenterHQ/epicenter | 4.8k | — | ~2k | Automated safety check: Pass | Custom licence | |
| TDD WorkflowhellangleZ/burn-in-cceverywhere-ralph | 112 | 11 repos | ~2.4k | Automated safety check: Pass | None | |
| Testing OpenLogi UIAprilNEA/OpenLogi | 23k | — | ~1.1k | Automated safety check: Pass | Apache-2.0 | |
| Go Testingcxuu/golang-skills | 170 | 1 repos | ~1.3k | Automated safety check: Pass | Apache-2.0 | |
| Contractssamchon/nestia | 2.2k | — | ~1.3k | Automated safety check: Pass | MIT | |
| JS-in-HTML Testingliaohch3/claude-tap | 3.3k | — | ~924 | Automated safety check: Pass | MIT |
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Categories
Questions about Cohesion Over Testability
What does Cohesion Over Testability do?
Collapse test-shaped production boundaries while preserving behavior and coverage. Cohesion Over Testability is an agent skill from EpicenterHQ/epicenter. Collapse test-shaped production boundaries while preserving behavior and coverage.
When should I use Cohesion Over Testability?
Cohesion Over Testability fits situations like: injected dependency; export exists mainly to let a unit test reach internals.
How do I install Cohesion Over Testability in Claude Code?
Run `npx skills add EpicenterHQ/epicenter --skill cohesion-over-testability -a claude-code`. Or copy the skill folder (.agents/skills/cohesion-over-testability in EpicenterHQ/epicenter) into .claude/skills/cohesion-over-testability in your project. Claude Code loads it when a task matches its description.
How do I install Cohesion Over Testability in Codex?
Run `npx skills add EpicenterHQ/epicenter --skill cohesion-over-testability -a codex`. Or copy the skill folder (.agents/skills/cohesion-over-testability in EpicenterHQ/epicenter) into .agents/skills/cohesion-over-testability in your project. Codex loads it when a task matches its description.
Can I use Cohesion Over Testability 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 EpicenterHQ/epicenter --skill cohesion-over-testability -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/cohesion-over-testability, .gemini/skills/cohesion-over-testability, .github/skills/cohesion-over-testability and .opencode/skills/cohesion-over-testability in your project.
What does Cohesion Over Testability need to run?
SKILL.md names no scripts, command-line tools or credentials: Cohesion Over Testability is instructions for the agent only.
Does Cohesion Over Testability 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 Cohesion Over Testability 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 Cohesion Over Testability use?
Cohesion Over Testability has a licence file (the repository's licence) that doesn't match a standard licence. Read it on GitHub before reusing the skill.
How many tokens does Cohesion Over Testability use?
About 2k tokens (SKILL.md is roughly 8.2k characters). Agents keep only the skill's name and description in context until a task matches; then they load SKILL.md in full. Its references folder adds about 2.4k tokens, read only when the agent opens those files.
What are the alternatives to Cohesion Over Testability?
Skills that share tags, products or a category with Cohesion Over Testability: TDD Workflow (hellangleZ/burn-in-cceverywhere-ralph, 112 stars), Testing OpenLogi UI (AprilNEA/OpenLogi, 23k stars), Go Testing (cxuu/golang-skills, 170 stars) and Contracts (samchon/nestia, 2.2k stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.
Who maintains Cohesion Over Testability?
EpicenterHQ (a GitHub organization) maintains it in EpicenterHQ/epicenter, which has 4,819 GitHub stars. The repository holds 65 skills in this directory. The repository was last updated on October 8, 2026.
Source: EpicenterHQ/epicenter on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.