ECC is a toolkit that organizes and improves how coding agents work through skills, memory, security checks, research practices, and related extensions. It is for developers using agents such as Claude Code, Codex, OpenCode, and Cursor.
Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
git clone --depth 1 https://github.com/affaan-m/ECCWrote 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/affaan-m/ecc/tdd-guide)<a href="https://agentmods.dev/agents/affaan-m/ecc/tdd-guide"><img src="https://agentmods.dev/badge/agents/affaan-m/ecc/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/affaan-m/ecc/tdd-guide"><img src="https://agentmods.dev/badge/agents/affaan-m/ecc/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.
Copies of this mod
8 near-identical copies found in the catalogue:
- tdd-guide — 100% identical, 0 lines differ
- tdd-guide — 100% identical, 0 lines differ
- tdd-guide — 100% identical, 0 lines differ
- tdd-guide — 100% identical, 0 lines differ
- tdd-guide — 100% identical, 0 lines differ
- tdd-guide — 95% identical, 6 lines differ
- tdd-guide — 95% identical, 6 lines differ
- tdd-guide — 95% identical, 13 lines differ
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 affaan-m/ECC (284,130 stars, last pushed today), 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. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-03.
Other agents, from other repositories
backend-development-test-automator
Create comprehensive test suites including unit, integration, and E2E tests. Supports TDD/BDD workflows. Use for test creation during feature development.
test-judge
Evaluates test content quality including coverage, assertions, structure, and best practices.
test-engineer
Specialized in Python testing with pytest. Expert in running tests, fixing failures, and ensuring test coverage. Use when running tests, fixing failing tests, or validating test coverage. Does NOT write new tests - focuses on running and fixing.
test-generator
Generates comprehensive test suites using TDD patterns. Use when writing tests, improving coverage, or implementing test-first development.
test-architect
Test stratejisi ve mimarisi agent'i. Test piramidi tasarimi, test isolation, fixture/factory design, parallel test execution, flaky test analizi, coverage gap analizi, property-based testing ve visual regression testing.
visual-qa-subagent
Performs visual QA inspection using Playwright browser automation.