testing.write_unit_tests

testing.write_unit_tests is a skill for Claude Code from causify-ai/helpers. It costs 13 tokens per session (208 once invoked), scanned A, original, Apache-2.0.

A unit-testing workflow that first proposes what a file should be tested for and then implements the approved plan. Unit tests check small pieces of code in isolation.

In plain words
What is it for?
Use it to plan and later write unit tests for a source file, following the project's testing rules.
Why use it?
It gives the developer a chance to review the test plan before any tests are added.

Skill for Claude Code

Written for Claude Code: installed under .claude/. Also seen: model in frontmatter; reads .claude/ paths.

Good fit Use it to plan and later write unit tests for a source file, following the project's testing rules.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/causify-ai/helpers/testing.write_unit_tests
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.

Any agent
npx skills add causify-ai/helpers --skill testing.write_unit_tests
Clone the repo
git clone --depth 1 https://github.com/causify-ai/helpers

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.

agentmods badge for testing.write_unit_tests

README.md
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Your own site
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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.

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Your own site · 80×15
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Per session 13 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 208 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. Third-party audits
  • NVIDIA SkillSpector warn 7 Sept 2026
SkillSpector: 1 finding, up to medium

These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →

  • medium Excessive Agency · line 3
    Skill selects an external model or provider that may use a different account or billing plan than the operator expects. Undisclosed model switches can cause unexpected cost or quota consumption.
    Fix: Remove the model/provider override or disclose it prominently and require explicit operator approval before invoking an external coding CLI or billed model.
How audits are shown
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.

ModelPer sessionOnce invoked
Fable 5.1 $0.00013 $0.00208
Opus 5.5 $0.00005 $0.00083
Sonnet 5.5 $0.00003 $0.00042
Haiku 4.5 $0.00001 $0.00021

Measured 1mo ago against content hash a63ad0678454, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

testing.write_unit_tests 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.

.claude/skills/testing.write_unit_tests/SKILL.md · 30 lines

What it actually says

Goal

  • Propose a unit test plan for a given file, then implement it after the user approves

Workflow

Propose a Unit Test Plan

  • Given a file <FILE>, create a comprehensive unit test plan according to the rules in .claude/skills/testing.rules.md
  • Create a file with a summary of what is going to be tested

Implement the Unit Test Plan

  • Wait for the user to review the plan and approve or modify it
  • Then implement it

Important

  • All invariants and conventions for unit tests are documented in .claude/skills/testing.rules.md
  • For all code you must follow the instructions in .claude/skills/coding.rules.md

Verification

  • Make sure everything in # Verification in .claude/skills/testing.rules.md is verified
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. 1mo ago Changed · +6 lines a63ad0678454
  2. 1mo ago First seen · 24 lines · 13 tokens per session scan A b97aaf13d0fc

Subscribe to this mod's changes

testing.write_unit_tests is a skill published in the GitHub repository causify-ai/helpers (150 stars, last pushed yesterday), licensed Apache-2.0. It adds 13 tokens to every session and 208 once invoked, about $0.0001 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.