EGC: Skill for Codex

.agents/skills/tdd-workflow/SKILL.md

tdd-workflow is a skill for Codex from Fmarzochi/EGC. It costs 43 tokens per session (2,431 once invoked), scanned A, a copy of tdd-workflow, Apache-2.0.

A test-driven development workflow, where tests are written before the code and checked at several levels. TDD is a way of building software by first describing the expected behavior with tests.

In plain words
What is it for?
Use it when adding features, fixing bugs, refactoring code, creating API endpoints, or building components, with unit, integration, and browser tests.
Why use it?
It reduces the risk of breaking existing behavior and requires edge cases, errors, and important user flows to be tested rather than assumed to work.

Skill for Codex

Written for Codex: agents/openai.yaml present. Also seen: installed under .agents/ (shared by several agents).

This is Fmarzochi/EGC's own configuration. It tells Codex how to work on EGC itself, so it is not a mod to install elsewhere. Copy it as a starting point and replace the rules that are about this project. Everything EGC configures →

Reuse

Borrowing it

Nothing to install: this file belongs to Fmarzochi/EGC. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file
curl -O https://raw.githubusercontent.com/Fmarzochi/EGC/main/.agents/skills/tdd-workflow/SKILL.md
Clone the repo
git clone --depth 1 https://github.com/Fmarzochi/EGC

Made for: Codex.

Wrote 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.

agentmods badge for tdd-workflow

README.md
[![agentmods](https://agentmods.dev/badge/skills/fmarzochi/egc/tdd-workflow.svg)](https://agentmods.dev/skills/fmarzochi/egc/tdd-workflow)
Your own site
<a href="https://agentmods.dev/skills/fmarzochi/egc/tdd-workflow"><img src="https://agentmods.dev/badge/skills/fmarzochi/egc/tdd-workflow.svg" alt="Measured on agentmods" height="20"></a>
Per session 43 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,431 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin 88% copy Near-identical to another mod in the catalogue.
Token cost

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.

ModelPer sessionOnce invoked
Fable 5.1 $0.00043 $0.02431
Opus 5 $0.00022 $0.01215
Sonnet 5 $0.00009 $0.00486
Haiku 4.5 $0.00004 $0.00243

Measured 7d ago against content hash 27cfe7148aeb, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-07, from the pricing page.

Security

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 7d 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.

Origin

This is a copy

88% identical to tdd-workflow — 12 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.

.agents/skills/tdd-workflow/SKILL.md · 410 lines

How it starts

The opening of the file, as written. The whole thing — 410 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 1: Write User Journeys

As a [role], I want to [action], so that [benefit]

Example:
As a user, I want to search for markets semantically,
so that I can find relevant markets even without exact keywords.

Step 2: Generate Test Cases

For each user journey, create comprehensive test cases:

describe('Semantic Search', () => {
  it('returns relevant markets for query', async () => {
    // Test implementation
  })

  it('handles empty query gracefully', async () => {
    // Test edge case
  })

  it('falls back to substring search when Redis unavailable', async () => {
    // Test fallback behavior
  })

  it('sorts results by similarity score', async () => {
    // Test sorting logic
  })
})

Step 3: Run Tests (They Should Fail)

npm test
# Tests should fail - we haven't implemented yet

Step 4: Implement Code

Write minimal code to make tests pass:

// Implementation guided by tests
export async function searchMarkets(query: string) {
  // Implementation here
}

Step 5: Run Tests Again

npm test
# Tests should now pass

Read the full file on GitHub · 410 lines

Files

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.

Changes

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.

  1. 7d ago First seen · 410 lines · 43 tokens per session scan A 27cfe7148aeb

Subscribe to this mod's changes

tdd-workflow is a skill published in the GitHub repository Fmarzochi/EGC (49 stars, last pushed today), licensed Apache-2.0. It adds 43 tokens to every session and 2,431 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 0 findings. It is 88% identical to tdd-workflow, differing in 12 lines, and is treated as a copy.

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