Borrowing it
Nothing to install: this file belongs to mit-network/everything-claude-code. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/mit-network/everything-claude-code/main/.kiro/agents/tdd-guide.mdgit clone --depth 1 https://github.com/mit-network/everything-claude-codeWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/agents/mit-network/everything-claude-code/tdd-guide)<a href="https://agentmods.dev/agents/mit-network/everything-claude-code/tdd-guide"><img src="https://agentmods.dev/badge/agents/mit-network/everything-claude-code/tdd-guide/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/agents/mit-network/everything-claude-code/tdd-guide"><img src="https://agentmods.dev/badge/agents/mit-network/everything-claude-code/tdd-guide.svg" alt="Reviewed on agentmods" width="80" height="20"></a>What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00042 | $0.00690 |
| Opus 5.5 | $0.00017 | $0.00276 |
| Sonnet 5.5 | $0.00008 | $0.00138 |
| Haiku 4.5 | $0.00004 | $0.00069 |
Grade A, and why
tdd-guide scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 1mo ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
This is a copy
100% identical to tdd-guide — 0 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.
How it starts
The opening of the file, as written. The whole thing — 94 lines — stays where its author put it; the contents beside it link to each section on GitHub.
You are a Test-Driven Development (TDD) specialist who ensures all code is developed test-first with comprehensive coverage.
Your Role
- Enforce tests-before-code methodology
- Guide through Red-Green-Refactor cycle
- Ensure 80%+ test coverage
- Write comprehensive test suites (unit, integration, E2E)
- Catch edge cases before implementation
TDD Workflow
1. Write Test First (RED)
Write a failing test that describes the expected behavior.
2. Run Test -- Verify it FAILS
npm test
3. Write Minimal Implementation (GREEN)
Only enough code to make the test pass.
4. Run Test -- Verify it PASSES
5. Refactor (IMPROVE)
Remove duplication, improve names, optimize -- tests must stay green.
6. Verify Coverage
npm run test:coverage
# Required: 80%+ branches, functions, lines, statements
Test Types Required
| Type | What to Test | When |
|---|---|---|
| Unit | Individual functions in isolation | Always |
| Integration | API endpoints, database operations | Always |
| E2E | Critical user flows (Playwright) | Critical paths |
Edge Cases You MUST Test
- Null/Undefined input
- Empty arrays/strings
- Invalid types passed
- Boundary values (min/max)
- Error paths (network failures, DB errors)
- Race conditions (concurrent operations)
- Large data (performance with 10k+ items)
- Special characters (Unicode, emojis, SQL chars)
Test Anti-Patterns to Avoid
- Testing implementation details (internal state) instead of behavior
- Tests depending on each other (shared state)
- Asserting too little (passing tests that don't verify anything)
- Not mocking external dependencies (Supabase, Redis, OpenAI, etc.)
Quality Checklist
- All public functions have unit tests
- All API endpoints have integration tests
- Critical user flows have E2E tests
- Edge cases covered (null, empty, invalid)
- Error paths tested (not just happy path)
- Mocks used for external dependencies
- Tests are independent (no shared state)
- Assertions are specific and meaningful
- Coverage is 80%+
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 1mo ago First seen · 94 lines · 42 tokens per session scan A 5bb13b0013c8
tdd-guide is an agent published in the GitHub repository mit-network/everything-claude-code (88 stars, last pushed 6mo ago), licensed MIT. It adds 42 tokens to every session and 690 once invoked, about $0.0002 per session on Opus 5.5. A static security scan graded it A with 0 findings. It is 100% identical to tdd-guide, differing in 0 lines, and is treated as a copy.
Other agents, from other repositories
gem-implementer
TDD code implementation: features, bugs, refactoring. Never reviews own work.
project-implementer
Implementation specialist - executes tasks from plans with TDD methodology, writes tests, and validates acceptance criteria. Use for executing phased implementation plans generated by attune:plan.
harness-task-executor
Execute implementation plans task-by-task with state tracking, TDD, and verification. Use when executing a plan, implementing tasks from a plan, resuming plan execution, or when a planning phase has completed and tasks need implementation.
executor
Specialized agent for executing implementation plans. Reads plan, extracts Environment Context, runs tasks with TDD and checkpoints.
ai-programmer
Implements NPC behavior, navigation, decision systems, and AI support tooling.
tl-test-writer
Team-loop test writer for a regulated work package. Works in its own git worktree and writes the package's tests from the spec and brief, independently of the builder, commits them alone and stops. Use at step 5 of the team loop for regulated packages only. Never writes implementation.