Borrowing it
Nothing to install: this file belongs to CES-Ltd/TitanX. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/CES-Ltd/TitanX/main/.claude/skills/testing/SKILL.mdgit clone --depth 1 https://github.com/CES-Ltd/TitanXWrote 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/ces-ltd/titanx/testing)<a href="https://agentmods.dev/skills/ces-ltd/titanx/testing"><img src="https://agentmods.dev/badge/skills/ces-ltd/titanx/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/ces-ltd/titanx/testing"><img src="https://agentmods.dev/badge/skills/ces-ltd/titanx/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 | $0.00055 | $0.01043 |
| Opus 5.5 | $0.00022 | $0.00417 |
| Sonnet 5.5 | $0.00011 | $0.00209 |
| Haiku 4.5 | $0.00006 | $0.00104 |
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.
This is a copy
100% identical to testing — 0 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.
How it starts
The opening of the file, as written. The whole thing — 139 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Testing Skill
Standards and workflow for writing and running tests. Every feature must be tested.
Announce at start: "I'm using testing skill to ensure proper test coverage."
Trigger Conditions
- Writing new tests for a feature or bug fix
- Adding a new feature (must include tests)
- Modifying logic that has existing tests (must update them)
- Before claiming work is complete
- Before committing code
Framework
Vitest 4 — configured in vitest.config.ts.
Test Structure
tests/
├── unit/ # Individual functions, utilities, components
├── integration/ # IPC, database, service interactions
├── regression/ # Regression test cases
└── e2e/ # End-to-end tests (Playwright, playwright.config.ts)
Two Test Environments
| Environment | When | File naming |
|---|---|---|
node (default) |
Main process, utilities, services | *.test.ts |
jsdom |
DOM/browser-dependent code | *.dom.test.ts |
Workflow
Step 1: Identify What to Test
Before writing tests, list the riskiest scenarios first:
- What happens when the dependency returns
undefined/ throws? - What happens at boundaries (empty list, max retries, past timestamp)?
- What is most likely to break in production?
Step 2: Write Tests
Follow these quality rules:
1. Describe behavior, not code structure
// Wrong — describes implementation
it('should call repo.getConversation', ...)
// Correct — describes behavior
it('should return cached task without hitting repo on second call', ...)
it('should reject with error when conversation does not exist', ...)
2. Every describe block must cover at least one failure path
Happy-path-only tests leave the most dangerous code untested.
3. One behavior per test
Keep each it() focused. More than 3 expect() calls in one test is a signal it is testing too much at once.
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 · 139 lines · 55 tokens per session scan A a40418b4bc17
testing is a skill published in the GitHub repository CES-Ltd/TitanX (49 stars, last pushed 6mo ago), licensed Apache-2.0. It adds 55 tokens to every session and 1,043 once invoked, about $0.0002 per session on Opus 5.5. A static security scan graded it A with 0 findings. It is 100% identical to testing, differing in 0 lines, and is treated as a copy.
Other skills, from other repositories
test-automation
Execute Vitest and Playwright test suites with result collection and failure analysis.
performance-engineer
Becomes a senior performance engineer who identifies bottlenecks, designs optimization strategies, and conducts load testing using systematic profiling and benchmarking methodology. Use when the user needs performance analysis, load testing, bottleneck identification, latency optimization, or capacity planning. Do NOT…
qa
QA testing skill with real browser automation. Use when asked to "test this site", "QA this page", "check for visual bugs", "verify the deploy", or when Hydra needs browser validation for UI changes. Requires the browse binary.
testing-tiers
Choose the right test tier for a change and keep the suite meaningful — unit, integration, real-entry-path, end-to-end, and snapshot tiers; test the real entry path rather than a hand-built harness; verify the world rather than the component's self-report; prefer the real implementation over a mock; and treat line…
run-verification
Run the full verification pipeline (lint, unit tests, E2E if UI changed) — invoke after code changes.
verify
Exercise the real app/API/CLI and collect observable evidence; tests alone do not count as end-to-end verification.