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
This one installs as part of its plugin. Adding the marketplace and installing the plugin brings it with everything else the plugin ships.
/plugin marketplace add affaan-m/ECC/plugin install 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/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.svg" alt="Measured on agentmods" 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 | $0.00043 | $0.03343 |
| Opus 5 | $0.00022 | $0.01672 |
| Sonnet 5 | $0.00009 | $0.00669 |
| Haiku 4.5 | $0.00004 | $0.00334 |
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 6d 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, 0 lines differ
- tdd-workflow — 100% identical, 0 lines differ
How it starts
The opening of the file, as written. The whole thing — 467 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.
- 6d 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 (250,130 stars, last pushed today), licensed MIT. It adds 43 tokens to every session and 3,343 once invoked, about $0.0002 per session on Opus 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
testing
Testing workflow and quality standards for writing and running tests. Use when: (1) Writing new tests, (2) Adding a new feature that needs tests, (3) Modifying logic that has existing tests, (4) Before claiming a task is complete.
js-in-html-testing
Test JS logic embedded in HTML using two-layer strategy - Python unit tests + Playwright browser integration tests.
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.
knowledge-engineering-quality-and-delivery-unit-integration-and-shared-test-harnesses
覆盖 CLI 与 Web 的 Vitest 分层、全局 mock、共享 fixture、临时存储和测试子进程所有权。 Navigate when: 新增或移动 unit/integration/CLI/E2E/Web 测试，调试并发差异、mock 污染、 超时、残留进程或临时目录清理。 Excludes: 付费 Provider 与发布矩阵（见 ../real-api-qualification-and-e2e/）； 性能、安全和快照专用门禁（见 ../performance-security-and-snapshot-gates/）。 Keywords: Vitest, setup.ts, test.js…
continuous-testing
Continuous test-driven development loop — after every code change, builds the project, starts the server, and runs Unit Tests, Integration Tests, and System Tests. Applies on top of microprofile-server skill. Use during development when you want full verification after each change. Triggers on "continuous testing"…