TypingMindTypingMindThe best frontend for AI
Principle Test Behavior Not Implementation logo

Principle Test Behavior Not Implementation

Community
koolamusic
principle-test-behavior-not-implementation

Apply when you write, change, or keep a test. Call the code as its users do and assert the exact result they see. Rewrite or delete a test that would pass if every imported function returned undefined.

Overview

Publisherkoolamusic
Repositoryclaudefiles
Skill nameprinciple-test-behavior-not-implementation
Stars
121
Forks
14
Bundled files
Instructions only
LicenseMIT
Links
Skill sourceRepositoryHomepage
  • Markdown instructions

    A SKILL.md file the model loads on demand, so it only costs tokens when a request actually matches.

  • Works with any LLM

    AI skills are plain Markdown, not provider-specific code, so this works with GPT, Claude, Gemini, Grok, or a local model.

  • Self-contained

    Everything the model needs lives in the instructions — no extra files to sync.

  • Open source

    Published by koolamusic on GitHub. Read the source before you install it.

Installation

Install the Principle Test Behavior Not Implementation AI skill in TypingMind to use it with any LLM, or drop it into another agent that reads SKILL.md.

1

Install in TypingMind

TypingMind installs a skill straight from its GitHub folder — it reads SKILL.md, bundles the resource files, and stores the result locally.

  1. Open the app and go to Plugins → Skills.
  2. Choose "Install from GitHub".
  3. Paste the skill folder URL below and confirm.
    https://github.com/koolamusic/claudefiles/tree/main/plugins/pstack/skills/principle-test-behavior-not-implementation
  4. Enable the skill in any chat where you want it available.
Plugins → Skills → Add skill → From GitHub URL, then paste the folder URL and press Continue.
2

Install in another agent

Any agent that reads the Agent Skills format can use this skill — copy the folder into that agent's skills directory.

Claude Code — .claude/skills
git clone --depth 1 https://github.com/koolamusic/claudefiles.git /tmp/claudefiles
mkdir -p .claude/skills
cp -r /tmp/claudefiles/plugins/pstack/skills/principle-test-behavior-not-implementation .claude/skills/principle-test-behavior-not-implementation
Restart Claude Code after copying so it picks up the new skill.

Use it in TypingMind

Enable Principle Test Behavior Not Implementation in any TypingMind chat and the model takes it from there. Its name and description sit in the system prompt, and the moment a request matches, the model loads the full instructions itself — you never invoke it by hand, and it costs no tokens until it is actually used.

The model loads Principle Test Behavior Not Implementation on its own as soon as a request matches it.

Works with any AI model

AI skills are plain Markdown instructions rather than provider-specific code, so Principle Test Behavior Not Implementation is not tied to the model it was written for. Install it once in TypingMind and use it with GPT-5, Claude, Gemini, Grok, DeepSeek, Mistral, Llama, or a local model you run yourself — all on your own API keys.

  • Loaded only when it is needed

    The system prompt carries just the name and description. The instructions are fetched on the first matching request, so an idle skill costs nothing.

  • Switch models mid-chat

    Because the skill is instructions rather than code, changing model does not break it — the next model reads the same SKILL.md.

Skill instructions

This is the SKILL.md content the model loads. Read it before installing — a skill is instructions your model will follow.

Test Behavior, Not Implementation

A test calls the code as its users do and asserts the exact result they see. Rewrite or delete any test that would still pass if every imported function returned undefined or a wrong value.

These shapes fail that check:

  • Loose or no assertion: toBeDefined, toBeTruthy, not.toThrow, toBeGreaterThan(0).
  • Call or absence only: toHaveBeenCalled, not.toHaveBeenCalled, toBeUndefined, toEqual([]).
  • Expected value computed by the code under test: expect(f(a)).toBe(f(a)).
  • Restated constant, config default, table row, or prompt string.
  • Assertions on data the test built, with no call to the subject.

Fix: call the subject in the test body with one concrete input and assert the literal output or effect. For a mock, assert the payload it received. For an absence, also assert the presence on another input. For a constant, test the mechanism that reads it with one input instead of restating the value.

Keep relation checks across table rows (a key in two tables, a parent that exists) and *.test-d.ts type checks.

Frequently asked questions

What does the Principle Test Behavior Not Implementation AI skill do?

Apply when you write, change, or keep a test. Call the code as its users do and assert the exact result they see. Rewrite or delete a test that would pass if every imported function returned undefined.

Why use Principle Test Behavior Not Implementation on TypingMind?

Because you install it once and use it with any model. Principle Test Behavior Not Implementation is plain Markdown rather than provider-specific code, so the same skill runs on GPT-5, Claude, Gemini, Grok, or a local model — and you can switch model mid-chat without it breaking. TypingMind runs on your own API keys, so you pay providers directly instead of a per-seat subscription, and your skills and chats stay in your own storage.

How do I install Principle Test Behavior Not Implementation in TypingMind?

Open Plugins → Skills → Install from GitHub in TypingMind and paste https://github.com/koolamusic/claudefiles/tree/main/plugins/pstack/skills/principle-test-behavior-not-implementation. TypingMind reads its SKILL.md and installs it as a skill you can enable per chat.

Which AI models can use Principle Test Behavior Not Implementation?

Any model you connect in TypingMind. AI skills are plain Markdown instructions rather than provider-specific code, so GPT, Claude, Gemini, Grok, and local models can all load this skill when a request matches it.

How many AI models can I use with Principle Test Behavior Not Implementation?

As many as you like. As long as a model supports skills, you can use Principle Test Behavior Not Implementation with it — GPT, Claude, Gemini, Grok, DeepSeek, Mistral, Llama and more — all on TypingMind with your own API keys.

Is the Principle Test Behavior Not Implementation AI skill free?

Yes. It is published on GitHub by koolamusic under the MIT license. You only pay your own AI provider for the tokens you use.

What are AI skills?

An AI skill is a reusable instruction bundle that teaches an AI model how to do one specific task. It follows the open Agent Skills format: a SKILL.md file with a name and description, plus any scripts, templates or reference files the model may need. The model reads the instructions only when your request matches the skill, so an installed skill costs nothing until it is used.

How are AI skills different from plugins or MCP servers?

A plugin or MCP server gives a model new tools to call — code that runs somewhere and returns a result. An AI skill gives the model knowledge and process instead: how to approach a task, which steps to follow, what good output looks like. Skills are plain Markdown, so they need no server, no API key and no runtime, and they work with any model.

Related AI Skills

View all
ruvnet logo

Plan Change

ruvnet
CommunityPopular

Turn a feature request into a minimal, file-level implementation plan before any code.

12.8K
97.4K
Instructions
View
paperclipai logo

Simplified English

paperclipai
OrganizationPopular

Write user-facing comments, plans, and documents in ASD-STE100 Simplified Technical English — short, unambiguous sentences with approved words and one meaning each — so readers understand them the…

16.2K
95.4K
Instructions
View
tt-a1i logo

Archify Review

tt-a1i
CommunityPopular

Review Archify issues, PRs, or code through value, cost, and impact to support evidence-based maintenance decisions. Use for issue triage, change reviews, and code quality assessments.

5.1K
75.3K
Instructions
View
ruvnet logo

Adr Verify

ruvnet
CommunityPopular

Read back adr-patterns + adr-edges namespaces, surface dangling refs / supersede cycles / status mismatches; exit 1 on cycles

8.6K
72.7K
Instructions
View

Set up your own AI workspace now

Get notified about new features and future giveaways by subscribing to our newsletter 👇