What is testing-patterns?

A guide to choosing and structuring unit, integration, and end-to-end tests. Unit tests check small pieces of code, while end-to-end tests check complete user flows.

Use it to design test coverage, arrange test steps, choose between test types, and plan mocking strategies.

It helps keep test suites reliable, readable, and appropriately balanced instead of making every test slow or difficult to maintain.

testing-patterns — Skill for Claude Code by bugrabilge

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 bugrabilge/bilge-development-kit --skill testing-patterns

Clone the repo

git clone --depth 1 https://github.com/bugrabilge/bilge-development-kit

Made for: Claude Code.

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/bugrabilge/bilge-development-kit/testing-patterns/github.svg)](https://agentmods.dev/skills/bugrabilge/bilge-development-kit/testing-patterns)

Your own site

<a href="https://agentmods.dev/skills/bugrabilge/bilge-development-kit/testing-patterns"><img src="https://agentmods.dev/badge/skills/bugrabilge/bilge-development-kit/testing-patterns/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/bugrabilge/bilge-development-kit/testing-patterns"><img src="https://agentmods.dev/badge/skills/bugrabilge/bilge-development-kit/testing-patterns.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 16 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 840 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 89% copy Near-identical to another mod 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	$0.00016	$0.00840
Opus 5	$0.00008	$0.00420
Sonnet 5	$0.00003	$0.00168
Haiku 4.5	$0.00002	$0.00084

Measured 5d ago against content hash f229085ad979, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-08, from the pricing page.

Security

Grade A, and why

testing-patterns 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 5d ago.

The scan reads SKILL.md. This mod also ships 1 executable file (scripts/test_runner.py), listed below but not scanned — reading those needs a real analyzer, not pattern matching.

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.

Origin

This is a copy

89% identical to testing-patterns — 4 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.

skills/testing-patterns/SKILL.md · 179 lines

How it starts

The opening of the file, as written. The whole thing — 179 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Testing Patterns

Principles for reliable test suites.

1. Testing Pyramid

        /\          E2E (Few)
       /  \         Critical flows
      /----\
     /      \       Integration (Some)
    /--------\      API, DB queries
   /          \
  /------------\    Unit (Many)
                    Functions, classes

2. AAA Pattern

Step	Purpose
Arrange	Set up test data
Act	Execute code under test
Assert	Verify outcome

3. Test Type Selection

When to Use Each

Type	Best For	Speed
Unit	Pure functions, logic	Fast (<50ms)
Integration	API, DB, services	Medium
E2E	Critical user flows	Slow

4. Unit Test Principles

Good Unit Tests

Principle	Meaning
Fast	< 100ms each
Isolated	No external deps
Repeatable	Same result always
Self-checking	No manual verification
Timely	Written with code

What to Unit Test

Test	Don't Test
Business logic	Framework code
Edge cases	Third-party libs
Error handling	Simple getters

5. Integration Test Principles

What to Test

Area	Focus
API endpoints	Request/response
Database	Queries, transactions
External services	Contracts

Setup/Teardown

Phase	Action
Before All	Connect resources
Before Each	Reset state
After Each	Clean up
After All	Disconnect

6. Mocking Principles

When to Mock

Mock	Don't Mock
External APIs	The code under test
Database (unit)	Simple dependencies
Time/random	Pure functions
Network	In-memory stores

Mock Types

Type	Use
Stub	Return fixed values
Spy	Track calls
Mock	Set expectations
Fake	Simplified implementation

7. Test Organization

Read the full file on GitHub · 179 lines

Files

What ships with it

1 file 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.

scripts/test_runner.py 6.9 KB runs code

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.

5d ago First seen · 179 lines · 16 tokens per session scan A f229085ad979

Subscribe to this mod's changes

testing-patterns is a skill published in the GitHub repository bugrabilge/bilge-development-kit (10 stars, last pushed 4mo ago), licensed MIT. It adds 16 tokens to every session and 840 once invoked, about $0.0001 per session on Opus 5. A static security scan graded it A with 0 findings. It is 89% identical to testing-patterns, differing in 4 lines, and is treated as a copy.

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