A TDD command that writes unit tests for a feature before the production code exists, so the tests initially fail. Unit tests check small parts of a program in isolation.

Use it to create one or more tests from a story's acceptance criteria and cover important edge cases.

It turns the requirements into executable checks before implementation begins.

p5-impl-red — Command for Claude Code by jonase47/ccpr

Install

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.

Clone the repo

git clone --depth 1 https://github.com/jonase47/ccpr

Made for: Claude Code.

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.

README.md

[![agentmods](https://agentmods.dev/badge/commands/jonase47/ccpr/p5-impl-red/github.svg)](https://agentmods.dev/commands/jonase47/ccpr/p5-impl-red)

Your own site

<a href="https://agentmods.dev/commands/jonase47/ccpr/p5-impl-red"><img src="https://agentmods.dev/badge/commands/jonase47/ccpr/p5-impl-red/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.

Your own site · 80×15

<a href="https://agentmods.dev/commands/jonase47/ccpr/p5-impl-red"><img src="https://agentmods.dev/badge/commands/jonase47/ccpr/p5-impl-red.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 0 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.

When invoked 519 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 original No closer match found 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.

Model	Per session	Once invoked
Fable 5.1	$0.00000	$0.00519
Opus 5.5	$0.00000	$0.00208
Sonnet 5.5	$0.00000	$0.00104
Haiku 4.5	$0.00000	$0.00052

Measured 1mo ago against content hash def66c3ff5c4, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

p5-impl-red 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.

commands/p5-impl-red.md · 65 lines

How it starts

The opening of the file, as written. The whole thing — 65 lines — stays where its author put it; the contents beside it link to each section on GitHub.

/p5-impl-red – Write Failing Tests (RED)

Writes unit tests for a feature BEFORE production code exists. Tests must fail.

Argument: $ARGUMENTS = [Feature name/Story ID]

If provided: Write tests for the named feature. If not provided: Ask which feature should be tested.

Prerequisites

Story identified in SPRINT.md
Acceptance criteria from BACKLOG.md known

Agent

Type: senior-developer
Model: sonnet

Context (Orchestrator prepares)

Orchestrator reads beforehand and provides inline:

From BACKLOG.md: acceptance criteria of the story (exact lines)
From ARCHITECTURE.md: affected modules/files (relevant section only)
From TEST_STRATEGY.md: test naming convention and framework

Prompt Template

Goal: Write failing unit tests for Story [ID]: [Title]

Acceptance Criteria: [inline from BACKLOG.md]

Affected Modules: [inline from ARCHITECTURE.md]

Output Format:

Test file(s) in the tests/ directory

Naming scheme: "should [behavior] when [condition]"

1 test per acceptance criterion + most important edge cases

Constraints:

Write ONLY tests, NO production code

Tests MUST fail (assert against not-yet-existing code)

Max. 15 test cases

Orchestrator Checkpoint

Tests cover all acceptance criteria?
Tests actually fail (not due to syntax errors)?
Test file is in the correct directory?

Output

Test file(s) in tests/

Handover Epilog

Update docs/HANDOVER.md:

What was created/changed
Open decisions → the ## Open Decisions table; a finding outside this command's scope goes to the ## Open Points inbox instead
Next Steps (according to ~/.claude/docs/NEXT_STEPS_REFERENCE.md)

Recommend 1-3 sensible next commands to the user:

Read docs/HANDOVER.md for the current project status
Consult ~/.claude/docs/NEXT_STEPS_REFERENCE.md for allowed transitions
Only suggest commands that match the current phase/sub-command status
If the current phase appears complete: recommend the gate

Read the full file on GitHub · 65 lines

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.

1mo ago Changed def66c3ff5c4
1mo ago First seen · 65 lines · 0 tokens per session scan A 1264881be139

Subscribe to this mod's changes

p5-impl-red is a command published in the GitHub repository jonase47/ccpr (1 stars, last pushed 26d ago), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 519 tokens. 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.

Claude Code TDD Testing Unit testing agentic-workflows ai-agents anthropic claude claude-code-agents

p5-impl-red