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
It runs from inside its repository, so the clone comes first — what it calls does not travel with the file alone.
git clone --depth 1 https://github.com/affaan-m/ECCnpx agentmods add skills/affaan-m/ecc/tdd-workflowWrote 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/skills/affaan-m/ecc/tdd-workflow)<a href="https://agentmods.dev/skills/affaan-m/ecc/tdd-workflow"><img src="https://agentmods.dev/badge/skills/affaan-m/ecc/tdd-workflow/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/skills/affaan-m/ecc/tdd-workflow"><img src="https://agentmods.dev/badge/skills/affaan-m/ecc/tdd-workflow.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- Socket pass
- Snyk pass
- NVIDIA SkillSpector pass
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 | $0.00043 | $0.03347 |
| Opus 5.5 | $0.00017 | $0.01339 |
| Sonnet 5.5 | $0.00009 | $0.00669 |
| Haiku 4.5 | $0.00004 | $0.00335 |
Grade A, and why
tdd-workflow 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
2 near-identical copies found in the catalogue:
- tdd-workflow — 100% identical, 1 lines differ
- tdd-workflow — 100% identical, 1 lines differ
How it starts
The opening of the file, as written. The whole thing — 468 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Test-Driven Development Workflow
This skill ensures all code development follows TDD principles with comprehensive test coverage.
When to Activate
- Writing new features or functionality
- Fixing bugs or issues
- Refactoring existing code
- Adding API endpoints
- Creating new components
Core Principles
1. Tests BEFORE Code
ALWAYS write tests first, then implement code to make tests pass.
2. Coverage Requirements
- Minimum 80% coverage (unit + integration + E2E)
- All edge cases covered
- Error scenarios tested
- Boundary conditions verified
3. Test Types
Unit Tests
- Individual functions and utilities
- Component logic
- Pure functions
- Helpers and utilities
Integration Tests
- API endpoints
- Database operations
- Service interactions
- External API calls
E2E Tests (Playwright)
- Critical user flows
- Complete workflows
- Browser automation
- UI interactions
TDD Workflow Steps
Step 0: Detect the Test Runner
Do not assume npm test. The commands in the steps and examples below use <test>, <test-watch>, and <coverage> as placeholders for the project's actual runner. Resolve them once before starting:
-
Run the package-manager detector (ships with ECC):
node scripts/setup-package-manager.js --detectIt resolves the package manager (npm / pnpm / yarn / bun) from, in order:
CLAUDE_PACKAGE_MANAGER,.claude/package-manager.json, thepackage.jsonpackageManagerfield, the lockfile, then global config. -
Distinguish the package manager from the test runner — they are not the same. A project can use Bun to install dependencies yet still run Jest or Vitest. Inspect
package.jsonscripts.testand the test files:scripts.testinvokesjest/vitest-> run through the detected PM (npm test,pnpm test,yarn test, orbun run test).scripts.testisbun test, or test filesimport { test, expect } from "bun:test", or there is no jest/vitest config but Bun is present -> use Bun's native runner (bun test). See Bun Native Test Pattern below.
What ships with it
1 file beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
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 Changed · +1 lines e9507695657b
- 1mo ago First seen · 467 lines · 43 tokens per session scan A 5a8868418170
tdd-workflow is a skill published in the GitHub repository affaan-m/ECC (284,906 stars, last pushed today), licensed MIT. It adds 43 tokens to every session and 3,347 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 2026-08-30.
Other skills, from other repositories
dogfood
Exploratory QA of web apps: find bugs, evidence, reports.
memstack-development-test-writer
Use this skill when the user says 'write tests', 'add tests', 'test coverage', 'unit tests', 'integration tests', 'component tests', 'mocking', 'edge cases', or needs to generate tests with proper mocking and edge case coverage. Do NOT use for refactoring plans or database migrations.
testing
Use when writing or reviewing Flutter/Dart tests (unit, widget, golden), fixing flaky tests, adding coverage, or choosing between unit and widget tests.
testing-patterns
Redirect — testing-patterns was split into 5 focused sub-skills. Use when looking for testing-patterns, writing tests, or test automation. Redirects to testing-unit, testing-e2e, testing-integration, testing-llm, or testing-perf.
app-verification
Builds and maintains a repo's own verification harness (verify CLI, doctor, worktree isolation, feature map, seed data) and a reproduce-first bug handoff. Use when asked to "build a verification harness", "add a doctor command", "prove every feature still works", or "reproduce this bug report".
testing-patterns
Testing strategy: pyramid, AAA, mocks/fakes/stubs, flaky tests, coverage. Triggers: test, fixture, mock, stub, e2e, TDD, Playwright, Cypress, flaky, coverage, property-based.