TESTING AND RELIABILITY / Jesse Vincent / Superpowers
Superpowers Test-Driven Development
Makes an observed failing behavior test the entry point for implementation and checks that assertions can detect real production mistakes.
“Use when implementing any feature or bugfix, before writing implementation code”
01 / THE REASONING
Why this made the selection.
- Requires verifying why a test fails before changing implementation, then running the project suite after the fix.
- Its test-design reference rejects mirrored expectations, source-text assertions and tests that only prove mocks were installed.
02 / THE REVIEW RECORD
What we actually inspected.
Source review has boundaries.
A clear record is more useful than a “safe” badge.
Material inspected
- skills/test-driven-development/SKILL.md
- skills/test-driven-development/writing-good-tests.md
- LICENSE
Our findings
- The definition separates expected assertion failures from errors caused by broken test setup.
- The reference requires hand-derived expectations and naming the production mutation each test should catch.
- Mock guidance preserves real side effects and reserves test-only cleanup for test utilities.
Not established by this review
- No consuming agent was evaluated for adherence to the process.
- No generated tests or production changes were executed.
The review applies to the material and revision named here. A newer upstream release can change its behavior.
03 / PUT IT TO WORK
Add a skill to your workflow.
DOCUMENTED COMMAND
npx skills add https://github.com/obra/superpowers/tree/5bf4e78011075bcfc0dc295f0724994cd123ee71/skills/test-driven-developmentCopying does not execute this command. It may retrieve a newer version than the reviewed source.
- Install the complete skill directory with its references and helpers; a copied SKILL.md alone may be incomplete.
- Choose the intended agent and project scope in the installer, then review its permissions before using the skill.
Before you start
- Node.js/npm for this installer
- An agent that supports the Agent Skills format
- A working project test command and permission to edit relevant code/tests
04 / FOLLOW THE EVIDENCE
The source trail.
Our notes are separate from the original resource.
Check upstream before adopting a new version.
https://github.com/obra/superpowers/blob/5bf4e78011075bcfc0dc295f0724994cd123ee71/skills/test-driven-development/SKILL.md
Supports: summary, upstreamDescription, whySelected, bestFor, limitations, review, compatibility, access
https://github.com/obra/superpowers/blob/5bf4e78011075bcfc0dc295f0724994cd123ee71/skills/test-driven-development/writing-good-tests.md
Supports: review, limitations, access
https://github.com/obra/superpowers/blob/5bf4e78011075bcfc0dc295f0724994cd123ee71/LICENSE
Supports: license
https://github.com/obra/superpowers/blob/5bf4e78011075bcfc0dc295f0724994cd123ee71/README.md
Supports: install, compatibility, access
https://github.com/vercel-labs/skills/blob/7407f3893ad4dceab546ac002c3ef806e4000c73/README.md
Supports: install
https://github.com/vercel-labs/skills/blob/7407f3893ad4dceab546ac002c3ef806e4000c73/src/git.ts
Supports: install