Openspec Plus TDD
elastic/terraform-provider-elasticstack
MANDATORY skill that activates whenever code is written to implement an OpenSpec change task.
Agent skill
Superpowers Test Driven Development
by christopherarter in christopherarter/superpowers-reasonix
Writing or fixing any code?. An agent skill from christopherarter/superpowers-reasonix.
Install Superpowers Test Driven Development
$ npx skills add christopherarter/superpowers-reasonix --skill superpowers-test-driven-development -a claude-codeProject install by default; add -g for ~/.claude/skills/.
$ gh skill install christopherarter/superpowers-reasonix superpowers-test-driven-development --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/christopherarter/superpowers-reasonix.git skills-src && mkdir -p .claude/skills && cp -r skills-src/skills/superpowers-test-driven-development .claude/skills/superpowers-test-driven-development && 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 "superpowers-test-driven-development" agent skill from https://github.com/christopherarter/superpowers-reasonix/tree/main/skills/superpowers-test-driven-development into .claude/skills/superpowers-test-driven-development/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "superpowers-test-driven-development", 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/christopherarter/superpowers-reasonix/tree/main/skills/superpowers-test-driven-developmentType 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 christopherarter/superpowers-reasonix --skill superpowers-test-driven-development -a codexProject install goes to .agents/skills/; add -g for ~/.codex/skills/.
$ gh skill install christopherarter/superpowers-reasonix superpowers-test-driven-development --agent codexProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/christopherarter/superpowers-reasonix.git skills-src && mkdir -p .agents/skills && cp -r skills-src/skills/superpowers-test-driven-development .agents/skills/superpowers-test-driven-development && rm -rf skills-srcUse ~/.agents/skills/ instead of .agents/skills for a personal install.
Codex skills documentation · loads skills from .agents/skills/
Install the "superpowers-test-driven-development" agent skill from https://github.com/christopherarter/superpowers-reasonix/tree/main/skills/superpowers-test-driven-development into .agents/skills/superpowers-test-driven-development/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "superpowers-test-driven-development", 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 christopherarter/superpowers-reasonix --skill superpowers-test-driven-development -a cursorProject install goes to .agents/skills/; add -g for ~/.cursor/skills/.
$ gh skill install christopherarter/superpowers-reasonix superpowers-test-driven-development --agent cursorProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/christopherarter/superpowers-reasonix.git skills-src && mkdir -p .cursor/skills && cp -r skills-src/skills/superpowers-test-driven-development .cursor/skills/superpowers-test-driven-development && 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 "superpowers-test-driven-development" agent skill from https://github.com/christopherarter/superpowers-reasonix/tree/main/skills/superpowers-test-driven-development into .cursor/skills/superpowers-test-driven-development/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "superpowers-test-driven-development", 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/christopherarter/superpowers-reasonix.git --path skills/superpowers-test-driven-development--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 christopherarter/superpowers-reasonix --skill superpowers-test-driven-development -a gemini-cliProject install goes to .agents/skills/; add -g for ~/.gemini/skills/.
$ gh skill install christopherarter/superpowers-reasonix superpowers-test-driven-development --agent gemini-cliProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/christopherarter/superpowers-reasonix.git skills-src && mkdir -p .gemini/skills && cp -r skills-src/skills/superpowers-test-driven-development .gemini/skills/superpowers-test-driven-development && 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 "superpowers-test-driven-development" agent skill from https://github.com/christopherarter/superpowers-reasonix/tree/main/skills/superpowers-test-driven-development into .gemini/skills/superpowers-test-driven-development/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "superpowers-test-driven-development", 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 christopherarter/superpowers-reasonix superpowers-test-driven-developmentInstalls 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 christopherarter/superpowers-reasonix --skill superpowers-test-driven-development -a github-copilotProject install goes to .agents/skills/; add -g for ~/.copilot/skills/.
$ git clone --depth 1 https://github.com/christopherarter/superpowers-reasonix.git skills-src && mkdir -p .github/skills && cp -r skills-src/skills/superpowers-test-driven-development .github/skills/superpowers-test-driven-development && 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 "superpowers-test-driven-development" agent skill from https://github.com/christopherarter/superpowers-reasonix/tree/main/skills/superpowers-test-driven-development into .github/skills/superpowers-test-driven-development/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "superpowers-test-driven-development", 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 christopherarter/superpowers-reasonix --skill superpowers-test-driven-development -a opencodeOpenCode documents no install command of its own. Project install goes to .agents/skills/; add -g for ~/.config/opencode/skills/.
$ gh skill install christopherarter/superpowers-reasonix superpowers-test-driven-development --agent opencodeProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/christopherarter/superpowers-reasonix.git skills-src && mkdir -p .opencode/skills && cp -r skills-src/skills/superpowers-test-driven-development .opencode/skills/superpowers-test-driven-development && 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 "superpowers-test-driven-development" agent skill from https://github.com/christopherarter/superpowers-reasonix/tree/main/skills/superpowers-test-driven-development into .opencode/skills/superpowers-test-driven-development/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "superpowers-test-driven-development", 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
superpowers-test-driven-development- GitHub stars
- 102
- Token cost
- ~1.9k tokens
- SKILL.md length
- 669 words
- Files
- 2 (incl. references)
- Skills in repo
- 11
- Repo updated
- First seen
- Licence
- MIT
At a glance
Writing or fixing any code?. An agent skill from christopherarter/superpowers-reasonix.
- Tasks that involve Test-driven development
- SKILL.md covers Overview, When to Use, The Iron Law and Red-Green-Refactor, plus 9 more sections
- Calls npm
- Tasks that involve Failing and flaky tests
What it does
Superpowers Test Driven Development is an agent skill from christopherarter/superpowers-reasonix. Writing or fixing any code? Load first — write the failing test before the code.
Its SKILL.md is about 1.9k tokens, which your agent loads only when the skill is triggered. The skill folder holds 2 other files, including reference files (for example `references/testing-anti-patterns.md`).
It sits in Testing & QA, covering Test-driven development and Failing and flaky tests. The repository describes itself as: Superpowers skill port to Reasonix coding harness. The licence is MIT.
When your agent uses it
- Tasks that involve Test-driven development
- Tasks that involve Failing and flaky tests
Example prompts
- “/superpowers-test-driven-development”
What it can do on your machine
Read from SKILL.md and the folder at commit d202ba4. 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
Shell commands in SKILL.md call:
npm
From the folder's file list and the shell code blocks in SKILL.md.
Network
No URLs in SKILL.md. Its commands use npm, which can reach the network depending on how they are called.
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
Superpowers Test Driven Development loads about 1.9k tokens when it runs, and up to ~3.4k if it reads all its reference files. Until then it costs about 29 tokens; SKILL.md has 669 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 christopherarter/superpowers-reasonix at commit d202ba4, republished under its MIT licence (© christopherarter). 669 words, ~1,881 tokens.
Download SKILL.mdSave it as
.claude/skills/superpowers-test-driven-development/SKILL.md (or your agent's skills folder). This skill also uses 1 other file; get the full folder from GitHub.- name
- superpowers-test-driven-development
- description
- Writing or fixing any code? Load first — write the failing test before the code.
Test-Driven Development (TDD)
Overview
Test first. Watch it fail. Write minimal code to pass.
Core principle: Didn't watch the test fail? You don't know it tests the right thing.
Break the letter of the rules = break the spirit.
When to Use
Always: new features, bug fixes, refactors, behavior changes.
Exceptions (ask your human partner): throwaway prototypes, generated code, config files.
"Skip TDD just this once"? Stop. That's rationalization.
The Iron Law
NO PRODUCTION CODE WITHOUT A FAILING TEST FIRSTCode before the test? Delete it. Start over. Don't keep it as "reference", don't "adapt" it, don't look at it. Delete means delete. Implement fresh from tests.
Red-Green-Refactor
digraph tdd_cycle {
rankdir=LR;
red [label="RED\nWrite failing test", shape=box, style=filled, fillcolor="#ffcccc"];
verify_red [label="Verify fails\ncorrectly", shape=diamond];
green [label="GREEN\nMinimal code", shape=box, style=filled, fillcolor="#ccffcc"];
verify_green [label="Verify passes\nAll green", shape=diamond];
refactor [label="REFACTOR\nClean up", shape=box, style=filled, fillcolor="#ccccff"];
next [label="Next", shape=ellipse];
red -> verify_red;
verify_red -> green [label="yes"];
verify_red -> red [label="wrong\nfailure"];
green -> verify_green;
verify_green -> refactor [label="yes"];
verify_green -> green [label="no"];
refactor -> verify_green [label="stay\ngreen"];
verify_green -> next;
next -> red;
}RED — write failing test
One minimal test. Shows what should happen.
<Good>
```typescript
test('retries failed operations 3 times', async () => {
let attempts = 0;
const operation = () => {
attempts++;
if (attempts < 3) throw new Error('fail');
return 'success';
};const result = await retryOperation(operation);
expect(result).toBe('success'); expect(attempts).toBe(3); });
Clear name, real behavior, one thing
</Good>
<Bad>
```typescript
test('retry works', async () => {
const mock = jest.fn()
.mockRejectedValueOnce(new Error())
.mockRejectedValueOnce(new Error())
.mockResolvedValueOnce('success');
await retryOperation(mock);
expect(mock).toHaveBeenCalledTimes(3);
});Vague name, tests mock not code
</Bad>
One behavior. Clear name. Real code (no mocks unless unavoidable).
Verify RED — watch it fail
MANDATORY. Never skip. Run via bash:
npm test path/to/test.test.tsConfirm: fails (not errors), failure message is the expected one, fails because feature missing (not a typo).
Passes? Testing existing behavior — fix the test. Errors? Fix, rerun till it fails right.
GREEN — minimal code
Simplest code that passes.
<Good>
```typescript
async function retryOperation<T>(fn: () => Promise<T>): Promise<T> {
for (let i = 0; i < 3; i++) {
try {
return await fn();
} catch (e) {
if (i === 2) throw e;
}
}
throw new Error('unreachable');
}
```
Just enough to pass
</Good><Bad>
```typescript
async function retryOperation<T>(
fn: () => Promise<T>,
options?: {
maxRetries?: number;
backoff?: 'linear' | 'exponential';
onRetry?: (attempt: number) => void;
}
): Promise<T> {
// YAGNI
}
```
Over-engineered
</Bad>Don't add features, refactor other code, or "improve" past the test.
Verify GREEN — watch it pass
MANDATORY.
npm test path/to/test.test.tsConfirm: passes, other tests still pass, output pristine (no errors/warnings).
Fails? Fix code, not test. Other tests fail? Fix now.
REFACTOR — clean up
After green only: kill duplication, improve names, extract helpers. Stay green. Don't add behavior.
Repeat
Next failing test, next feature.
Good Tests
| Quality | Good | Bad |
|---|---|---|
| Minimal | One thing. "and" in name? Split it. | test('validates email and domain and whitespace') |
| Clear | Name describes behavior | test('test1') |
| Shows intent | Demonstrates desired API | Obscures what code should do |
Common Rationalizations
| Excuse | Reality |
|---|---|
| "Too simple to test" | Simple code breaks. Test takes 30 seconds. |
| "I'll test after" | Tests passing immediately prove nothing. |
| "Tests after achieve same goals" | Tests-after = "what does this do?" Tests-first = "what should this do?" |
| "Already manually tested" | Ad-hoc ≠ systematic. No record, can't re-run. |
| "Deleting X hours is wasteful" | Sunk cost. Keeping unverified code is tech debt. |
| "Keep as reference, write tests first" | You'll adapt it. That's testing after. Delete means delete. |
| "Need to explore first" | Fine. Throw away exploration, start with TDD. |
| "Test hard = design unclear" | Listen to the test. Hard to test = hard to use. |
| "TDD will slow me down" | TDD faster than debugging. Pragmatic = test-first. |
| "Manual test faster" | Manual doesn't prove edge cases. You'll re-test every change. |
| "Existing code has no tests" | You're improving it. Add tests for it. |
Show full SKILL.md (246 more words)Show less
Red Flags — STOP and Start Over
- Code before test
- Test passes immediately, or you can't explain why it failed
- "I'll test after" / "tests after achieve the same purpose"
- "Keep as reference" / "adapt existing code"
- "Already spent X hours, deleting is wasteful"
- "TDD is dogmatic, I'm being pragmatic" / "this is different because…"
All mean: delete code, start over with TDD.
Example: Bug Fix
Bug: empty email accepted.
RED
test('rejects empty email', async () => {
const result = await submitForm({ email: '' });
expect(result.error).toBe('Email required');
});Verify RED
$ npm test
FAIL: expected 'Email required', got undefinedGREEN
function submitForm(data: FormData) {
if (!data.email?.trim()) {
return { error: 'Email required' };
}
// ...
}Verify GREEN
$ npm test
PASSREFACTOR — extract validation for more fields if needed.
Verification Checklist
- Every new function/method has a test
- Watched each test fail before implementing
- Each test failed for the expected reason (feature missing, not a typo)
- Wrote minimal code to pass
- All tests pass, output pristine
- Tests use real code (mocks only if unavoidable)
- Edge cases and errors covered
Can't check all? You skipped TDD. Start over.
When Stuck
| Problem | Solution |
|---|---|
| Don't know how to test | Write the wished-for API. Assertion first. Ask your human partner. |
| Test too complicated | Design too complicated. Simplify the interface. |
| Must mock everything | Code too coupled. Use dependency injection. |
| Test setup huge | Extract helpers. Still complex? Simplify design. |
Debugging Integration
Bug? Write a failing test reproducing it. Follow the cycle — the test proves the fix and blocks regression. Never fix bugs without a test. (See superpowers-systematic-debugging.)
Testing Anti-Patterns
Adding mocks/test utils? Consult the Testing Anti-Patterns reference (auto-included below): testing mock not real behavior; test-only methods in prod classes; mocking without understanding deps.
Final Rule
Production code → test exists and failed first
Otherwise → not TDDNo exceptions without your human partner's permission.
© christopherarter, MIT. Rendered from Markdown: HTML in the file is shown as text, images as links, and headings moved down two levels. Raw file
Files
SKILL.md and 1 other file (references) in skills/superpowers-test-driven-development of christopherarter/superpowers-reasonix.
- SKILL.md
- references/testing-anti-patterns.md
Open the folder on GitHubat commit d202ba4
Compare with similar skills
Superpowers Test Driven Development 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 |
|---|---|---|---|---|---|---|
| Superpowers Test Driven Development this skillchristopherarter/superpowers-reasonix | 102 | — | ~1.9k | Automated safety check: Pass | MIT | |
| Openspec Plus TDDelastic/terraform-provider-elasticstack | 210 | 1 repos | ~4.7k | Automated safety check: Pass | Apache-2.0 | |
| Fix BugMelbourneDeveloper/dart_node | 113 | 1 repos | ~709 | Automated safety check: Notes | None | |
| Evanflow Debugevanklem/evanflow | 418 | — | ~760 | Automated safety check: Pass | Custom licence | |
| TDDcodeaholicguy/ai-devkit | 1.6k | — | ~838 | Automated safety check: Pass | Apache-2.0 | |
| TDD Workflows TDD Greenaiskillstore/marketplace | 430 | 6 repos | ~568 | Automated safety check: Pass | None |
Similar skills
- Official
Fix Bug
MelbourneDeveloper/dart_node
Fix a bug using test-driven development. An agent skill from MelbourneDeveloper/dart_node.
Evanflow Debug
evanklem/evanflow
Root-cause discipline for bugs, test failures, and unexpected behavior.
TDD
codeaholicguy/ai-devkit
AI DevKit · Test-driven development — write a failing test before writing production code.
TDD Workflows TDD Green
aiskillstore/marketplace
Implement the minimal code needed to make failing tests pass in the TDD green phase.
Test First Changes
pdparchitect/noodle
Test-first procedure for every behaviour change in Noodle. An agent skill from pdparchitect/noodle.
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Superpowers Brainstorming
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Superpowers Receiving Code Review
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Superpowers Using Git Worktrees
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Related
Categories
Questions about Superpowers Test Driven Development
What does Superpowers Test Driven Development do?
Writing or fixing any code?. An agent skill from christopherarter/superpowers-reasonix. Superpowers Test Driven Development is an agent skill from christopherarter/superpowers-reasonix. Writing or fixing any code?
When should I use Superpowers Test Driven Development?
Superpowers Test Driven Development fits situations like: tasks that involve Test-driven development; tasks that involve Failing and flaky tests.
How do I install Superpowers Test Driven Development in Claude Code?
Run `npx skills add christopherarter/superpowers-reasonix --skill superpowers-test-driven-development -a claude-code`. Or copy the skill folder (skills/superpowers-test-driven-development in christopherarter/superpowers-reasonix) into .claude/skills/superpowers-test-driven-development in your project. Claude Code loads it when a task matches its description.
How do I install Superpowers Test Driven Development in Codex?
Run `npx skills add christopherarter/superpowers-reasonix --skill superpowers-test-driven-development -a codex`. Or copy the skill folder (skills/superpowers-test-driven-development in christopherarter/superpowers-reasonix) into .agents/skills/superpowers-test-driven-development in your project. Codex loads it when a task matches its description.
Can I use Superpowers Test Driven Development 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 christopherarter/superpowers-reasonix --skill superpowers-test-driven-development -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/superpowers-test-driven-development, .gemini/skills/superpowers-test-driven-development, .github/skills/superpowers-test-driven-development and .opencode/skills/superpowers-test-driven-development in your project.
What does Superpowers Test Driven Development need to run?
Going by SKILL.md and its folder, Superpowers Test Driven Development needs the command-line tools its instructions call (npm).
Does Superpowers Test Driven Development access the network?
SKILL.md contains no URLs. Its commands use npm, which can reach the network depending on how they are called. This is read from the text; nothing was executed.
Is Superpowers Test Driven Development 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 Superpowers Test Driven Development use?
Superpowers Test Driven Development 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 Superpowers Test Driven Development use?
About 1.9k tokens (SKILL.md is roughly 7.5k 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 1.5k tokens, read only when the agent opens those files.
What are the alternatives to Superpowers Test Driven Development?
Skills that share tags, products or a category with Superpowers Test Driven Development: Openspec Plus TDD (elastic/terraform-provider-elasticstack, 210 stars), Fix Bug (MelbourneDeveloper/dart_node, 113 stars), Evanflow Debug (evanklem/evanflow, 418 stars) and TDD (codeaholicguy/ai-devkit, 1.6k stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.
Who maintains Superpowers Test Driven Development?
christopherarter (a GitHub user) maintains it in christopherarter/superpowers-reasonix, which has 102 GitHub stars. The repository holds 11 skills in this directory. The repository was last updated on August 20, 2026.
Source: christopherarter/superpowers-reasonix on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.