How do I install the Testing Patterns skill?

Run npx skillmds@latest add anhvu1107/testing-patterns in your terminal (requires Node.js), paste this page's agent-chat prompt into Claude, Cursor, or any MCP-connected agent, or download the SKILL.md file and copy it into your agent's skills directory.

What does the Testing Patterns skill do?

--- It is listed under AI & ML on SkillMD.

Is Testing Patterns safe to use?

This skill has not completed SkillMD's automated safety review yet. SkillMD never runs a skill's scripts for you; review the SKILL.md before installing.

Which AI agents work with Testing Patterns?

This skill is tagged as working with Claude Code, Claude.ai, OpenAI Codex. SKILL.md is an open format, so most agents that read a skills directory can load it too.

Is Testing Patterns free to use?

Yes. Installing skills from SkillMD is free, and the skill stays under its author's original license.

Who published Testing Patterns?

anhvu1107 (@anhvu1107) published this skill. Their other Agent Skills are listed on their SkillMD profile.

Testing Patterns by anhvu1107 — Agent Skill

Name: Testing Patterns
Author: anhvu1107

File contents

--- name: testing-patterns description: ALWAYS use this when choosing or improving test strategy, test shape, coverage boundaries, or the right mix of unit, integration, and end-to-end checks.

Testing Patterns

Selective Reading Rule

Start with:

references/senior-master-standard.md
references/usage-routing.md
references/quality-checklist.md

Then load only the inherited docs, scripts, assets, or examples that match the user's actual task.

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

Naming

Pattern	Example
Should behavior	"should return error when..."
When condition	"when user not found..."
Given-when-then	"given X, when Y, then Z"

Grouping

Level	Use
describe	Group related tests
it/test	Individual case
beforeEach	Common setup

8. Test Data

Strategies

Approach	Use
Factories	Generate test data
Fixtures	Predefined datasets
Builders	Fluent object creation

Principles

Use realistic data
Randomize non-essential values (faker)
Share common fixtures
Keep data minimal

9. Best Practices

Practice	Why
One assert per test	Clear failure reason
Independent tests	No order dependency
Fast tests	Run frequently
Descriptive names	Self-documenting
Clean up	Avoid side effects

10. Anti-Patterns

âŒ Don't	âœ… Do
Test implementation	Test behavior
Duplicate test code	Use factories
Complex test setup	Simplify or split
Ignore flaky tests	Fix root cause
Skip cleanup	Reset state

Remember: Tests are documentation. If someone can't understand what the code does from the tests, rewrite them.

---name: testing-patternsdescription: ---------name: testing-patternsdescription: ALWAYS use this when choosing or improving test strategy, test shape, coverage boundaries, or the right mix of unit, integration, and end-to-end checks.---# Testing Patterns## Selective Reading RuleStart with:- `references/senior-master-standard.md`- `references/usage-routing.md`- `references/quality-checklist.md`Then load only the inherited docs, scripts, assets, or examples that match the user's actual task.> 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### Naming| Pattern | Example ||---------|---------|| Should behavior | "should return error when..." || When condition | "when user not found..." || Given-when-then | "given X, when Y, then Z" |### Grouping| Level | Use ||-------|-----|| describe | Group related tests || it/test | Individual case || beforeEach | Common setup |---## 8. Test Data### Strategies| Approach | Use ||----------|-----|| Factories | Generate test data || Fixtures | Predefined datasets || Builders | Fluent object creation |### Principles- Use realistic data- Randomize non-essential values (faker)- Share common fixtures- Keep data minimal---## 9. Best Practices| Practice | Why ||----------|-----|| One assert per test | Clear failure reason || Independent tests | No order dependency || Fast tests | Run frequently || Descriptive names | Self-documenting || Clean up | Avoid side effects |---## 10. Anti-Patterns| âŒ Don't | âœ… Do ||----------|-------|| Test implementation | Test behavior || Duplicate test code | Use factories || Complex test setup | Simplify or split || Ignore flaky tests | Fix root cause || Skip cleanup | Reset state |---> **Remember:** Tests are documentation. If someone can't understand what the code does from the tests, rewrite them.

Frequently asked questions

Testing Patterns

File contents

﻿--- name: testing-patterns description: ALWAYS use this when choosing or improving test strategy, test shape, coverage boundaries, or the right mix of unit, integration, and end-to-end checks.

Testing Patterns

Selective Reading Rule

1. Testing Pyramid

2. AAA Pattern

3. Test Type Selection

When to Use Each

4. Unit Test Principles

Good Unit Tests

What to Unit Test

5. Integration Test Principles

What to Test

Setup/Teardown

6. Mocking Principles

When to Mock

Mock Types

7. Test Organization

Naming

Grouping

8. Test Data

Strategies

Principles

9. Best Practices

10. Anti-Patterns

Related skills

Frequently asked questions

How do I install the Testing Patterns skill?

What does the Testing Patterns skill do?

Is Testing Patterns safe to use?

Which AI agents work with Testing Patterns?

Is Testing Patterns free to use?

Who published Testing Patterns?

--- name: testing-patterns description: ALWAYS use this when choosing or improving test strategy, test shape, coverage boundaries, or the right mix of unit, integration, and end-to-end checks.