tdd

Drive development with Red-Green-Refactor using isolated test-writer, implementer, and refactorer subagents so tests reflect intent rather than anticipated implementation.

Workflow

1. Specify: restate the desired behavior in 1–2 sentences and identify the testing framework.
2. Red — tdd-test-writer subagent: spec only, no implementation. Returns failing test path + failure output.
3. Green — tdd-implementer subagent: failing test only, no spec or earlier drafts. Smallest implementation that turns it green.
4. Refactor — tdd-refactorer subagent: post-Green code only. Improve clarity without changing behavior. Tests must stay green.
5. Loop for each behavior.

Threat model

Context isolation is honor system: each subagent's prompt forbids reading certain inputs, and tools fields keep the surface narrow. The parent agent must honor the boundary; this is not a sandbox.

Install

gh skill install s-hiraoku/claude-harnesses tdd --scope project

Part of tdd-pack. Slash command: /tdd <behavior spec>.