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.
npx skills add krzysztofsurdy/code-virtuoso --skill testinggit clone --depth 1 https://github.com/krzysztofsurdy/code-virtuosoWrote 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/krzysztofsurdy/code-virtuoso/testing)<a href="https://agentmods.dev/skills/krzysztofsurdy/code-virtuoso/testing"><img src="https://agentmods.dev/badge/skills/krzysztofsurdy/code-virtuoso/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.
<a href="https://agentmods.dev/skills/krzysztofsurdy/code-virtuoso/testing"><img src="https://agentmods.dev/badge/skills/krzysztofsurdy/code-virtuoso/testing.svg" alt="Reviewed on agentmods" width="80" 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 | $0.00103 | $0.02628 |
| Opus 5.5 | $0.00041 | $0.01051 |
| Sonnet 5.5 | $0.00021 | $0.00526 |
| Haiku 4.5 | $0.00010 | $0.00263 |
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 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.
How it starts
The opening of the file, as written. The whole thing — 276 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Testing
A disciplined approach to verifying that software behaves correctly, remains stable under change, and communicates intent to future developers. Good tests act as living documentation, a safety net for refactoring, and a design feedback mechanism.
This skill covers universal testing concepts that apply regardless of language, framework, or tooling.
When to Use
- Designing a test strategy for a new project or feature
- Deciding what level of testing (unit, integration, e2e) a piece of code needs
- Evaluating whether existing tests are providing value or creating drag
- Applying TDD to drive design decisions
- Debugging a flaky or brittle test suite
- Reviewing test code for quality and maintainability
Testing Pyramid
The testing pyramid describes the ideal distribution of tests across three levels. More tests at the base, fewer at the top.
/ E2E \ Few, slow, expensive
/----------\
/ Integration \ Moderate number, moderate speed
/----------------\
/ Unit Tests \ Many, fast, cheap
/____________________\
Unit Tests (Base)
- Test a single unit of behavior in isolation (a function, a method, a small class)
- No I/O, no database, no network, no file system
- Execute in milliseconds
- Should form the majority of your test suite (roughly 70%)
- Fast feedback loop enables rapid iteration
Integration Tests (Middle)
- Test how multiple units collaborate, or how code interacts with external systems
- May involve a real database, message queue, or HTTP endpoint
- Execute in seconds
- Verify that wiring, configuration, and contracts between components work
- Roughly 20% of your test suite
End-to-End Tests (Top)
- Test complete user journeys through the full system
- Interact with the application as a user would
- Slowest, most brittle, most expensive to maintain
- Reserve for critical business paths only
- Roughly 10% of your test suite
The Ice Cream Cone Antipattern
The inverted pyramid: many e2e tests, few unit tests. Symptoms:
What ships with it
3 files 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.
- 1mo ago First seen · 276 lines · 103 tokens per session scan A 904a18106822
testing is a skill published in the GitHub repository krzysztofsurdy/code-virtuoso (39 stars, last pushed 5mo ago), licensed MIT. It adds 103 tokens to every session and 2,628 once invoked, about $0.0004 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.
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