What is test-strategy?

A plan for testing a code change or feature, including risks, edge cases, test data, and which tests should be written first.

It helps developers examine existing code and tests, choose unit, integration, or end-to-end tests, and produce prioritized test cases for later implementation.

It prevents important behaviors and unusual inputs from being missed when deciding what to test.

test-strategy — Skill for Claude Code and Codex by NickPolyder

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 NickPolyder/NP.CoPilot.Config --skill test-strategy

Clone the repo

git clone --depth 1 https://github.com/NickPolyder/NP.CoPilot.Config

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/nickpolyder/np.copilot.config/test-strategy/github.svg)](https://agentmods.dev/skills/nickpolyder/np.copilot.config/test-strategy)

Your own site

<a href="https://agentmods.dev/skills/nickpolyder/np.copilot.config/test-strategy"><img src="https://agentmods.dev/badge/skills/nickpolyder/np.copilot.config/test-strategy/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/nickpolyder/np.copilot.config/test-strategy"><img src="https://agentmods.dev/badge/skills/nickpolyder/np.copilot.config/test-strategy.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 42 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 3,225 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	$0.00042	$0.03225
Opus 5.5	$0.00017	$0.01290
Sonnet 5.5	$0.00008	$0.00645
Haiku 4.5	$0.00004	$0.00323

Measured 1mo ago against content hash f2075ca34b76, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

test-strategy 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.

skills/test-strategy/SKILL.md · 404 lines

How it starts

The opening of the file, as written. The whole thing — 404 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Purpose

Shared policy: Follow instructions/coordination.instructions.md for precedence, invocation, delegation, and handoffs. Apply instructions/workflow.instructions.md for proportional work and verification.

You are creating a forward-looking test strategy for a feature or code change.

Your goals are to:

Analyze the feature/code to understand what needs testing.
Design a test pyramid — allocate unit, integration, and E2E tests appropriately.
Discover edge cases systematically using structured techniques.
Define test data strategy — how test data is created, managed, and cleaned up.
Produce prioritized test cases that developers can implement later.
Identify coverage risks and existing test signals that should shape the plan.

When to use this skill

Use this skill whenever:

A new feature needs a test plan before or during implementation.
The user asks for a test strategy, test plan, or coverage analysis.
Existing tests need context for planning upcoming work, without retroactive gap filling.
A critical upcoming module needs comprehensive test coverage.

Do not use this skill for:

Writing individual test implementations (developers do that; this skill plans the strategy).
Pre-commit reviews (use the git-commit-review skill).
General code reviews (use the code-reviewer agent).
Retroactively auditing existing code/tests or filling discovered gaps — use test-gap-analysis.

Strategy process

Step 1: Analyze the target

Understand what you're creating a test strategy for:

Read the code — understand the components, services, and data flow.
Identify the domain — what business logic is involved?
Map the dependencies — what does this code depend on? What depends on it?
Check existing tests — what's already tested? What's missing?
Identify risk areas — where would bugs cause the most damage?

Step 2: Risk-based prioritization

Categorize areas by risk level:

Read the full file on GitHub · 404 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 · -3 lines f2075ca34b76
1mo ago First seen · 407 lines · 42 tokens per session scan A 3c7ade2edc62

Subscribe to this mod's changes

test-strategy is a skill published in the GitHub repository NickPolyder/NP.CoPilot.Config (2 stars, last pushed 1mo ago), licensed MIT. It adds 42 tokens to every session and 3,225 once invoked, about $0.0002 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 2026-08-31.

Testing

research-engineer

An uncompromising Academic Research Engineer. Operates with absolute scientific rigor, objective criticism, and zero flair. Focuses on theoretical correctness, formal verification, and optimal implementation across any required technology.

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Compare extracts from two Tika builds over a corpus to detect regressions in content, encoding, exceptions, and embedded-document handling. Use for "compare before/after extracts", "eval this change against the corpus".

apache/tika · 50 tokens

cua-driver

Use Cua Driver for desktop or browser tasks that are awkward or unavailable through Bash/APIs, or when the user explicitly wants GUI interaction: app testing, visual bug reproduction, form filling, calendar entry, screenshots, and demo recording. Also covers Cua setup; not OpenAI Codex Computer Use or web research.

davidondrej/skills · 68 tokens

test-strategy