A guide to writing automated software tests. Tests are programs that check whether other programs behave as expected.

Use it to structure tests, name them clearly, cover empty and boundary inputs, isolate test data, check integrations, and test failure cases.

It helps catch broken behavior, boundary cases, and error handling before changes reach users.

testing — Skill for Claude Code and Codex by AgriciDaniel

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 AgriciDaniel/claude-code-essentials-vs-code --skill testing

Clone the repo

git clone --depth 1 https://github.com/AgriciDaniel/claude-code-essentials-vs-code

Made for: Claude Code, 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.

README.md

[![agentmods](https://agentmods.dev/badge/skills/agricidaniel/claude-code-essentials-vs-code/testing/github.svg)](https://agentmods.dev/skills/agricidaniel/claude-code-essentials-vs-code/testing)

Your own site

<a href="https://agentmods.dev/skills/agricidaniel/claude-code-essentials-vs-code/testing"><img src="https://agentmods.dev/badge/skills/agricidaniel/claude-code-essentials-vs-code/testing/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/skills/agricidaniel/claude-code-essentials-vs-code/testing"><img src="https://agentmods.dev/badge/skills/agricidaniel/claude-code-essentials-vs-code/testing.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 5 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 120 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	$0.00005	$0.00120
Opus 5.5	$0.00002	$0.00048
Sonnet 5.5	$0.00001	$0.00024
Haiku 4.5	$0.00001	$0.00012

Measured 2mo ago against content hash 2fde87db12ae, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

testing 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 2mo 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.

templates/skills/testing/SKILL.md · 17 lines

What it actually says

When writing tests:

Use descriptive names: "should [behavior] when [condition]"
Follow Arrange-Act-Assert (AAA) pattern
Test edge cases: null, empty, boundary values
Mock external dependencies appropriately
Prefer integration tests for critical paths
Aim for 80% coverage minimum
Use test fixtures for complex data setup
Test error scenarios and edge cases
Keep tests independent and isolated
Use parameterized tests for similar scenarios

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.

2mo ago First seen · 17 lines · 5 tokens per session scan A 2fde87db12ae

Subscribe to this mod's changes

testing is a skill published in the GitHub repository AgriciDaniel/claude-code-essentials-vs-code (66 stars, last pushed 2mo ago), licensed MIT. It adds 5 tokens to every session and 120 once invoked, about $0.0000 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.

Claude Code Testing ai claude-code-skill developer-tools open-source

testing next to 6 skills from other repositories
Mod	Type	Stars	Last push	Licence	Scan	Tokens	Works with
testingAgriciDaniel/claude-code-essentials-vs-code	Skill	66	2mo ago	MIT	A	5	Claude Code, Codex
wiki-ingestAgriciDaniel/claude-obsidian	Skill	16k	14d ago	MIT	A	88	Claude Code
autoresearchAgriciDaniel/claude-obsidian	Skill	16k	14d ago	MIT	A	80	Claude Code
obsidian-basesAgriciDaniel/claude-obsidian	Skill	16k	14d ago	MIT	A	75	Claude Code
saveAgriciDaniel/claude-obsidian	Skill	16k	14d ago	MIT	A	80	Claude Code
wiki-retrieveAgriciDaniel/claude-obsidian	Skill	16k	14d ago	MIT	A	81	Claude Code
wikiAgriciDaniel/claude-obsidian	Skill	16k	14d ago	MIT	A	84	Claude Code