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Skill ยท Testing

Tdd workflow

Test-Driven Development workflow principles. RED-GREEN-REFACTOR cycle.

Agentic Awesome SkillsAdded Sep 5, 2026
Use it in my AI

How to use it

  1. Start your plan and connect your AI once
  2. Add the skill to your AI, one time only: press Copy skill and paste it into your AI's instructions: a project in ChatGPT, Claude or Grok, a Gem in Gemini, an agent in Microsoft 365 Copilot, or a rule in Cursor. It stays there for every new chat. In Kimi, paste it at the start of a new chat.
  3. Ask for the task in your own words, or say it directly:
Use the Tdd workflow skill to help me with this.
SKILL.md

TDD Workflow

Write tests first, code second.

1. The TDD Cycle

๐Ÿ”ด RED โ†’ Write failing test
    โ†“
๐ŸŸข GREEN โ†’ Write minimal code to pass
    โ†“
๐Ÿ”ต REFACTOR โ†’ Improve code quality
    โ†“
   Repeat...

2. The Three Laws of TDD

  1. Write production code only to make a failing test pass
  2. Write only enough test to demonstrate failure
  3. Write only enough code to make the test pass

3. RED Phase Principles

What to Write

FocusExample
Behavior"should add two numbers"
Edge cases"should handle empty input"
Error states"should throw for invalid data"

RED Phase Rules

  • Test must fail first
  • Test name describes expected behavior
  • One assertion per test (ideally)

4. GREEN Phase Principles

Minimum Code

PrincipleMeaning
YAGNIYou Aren't Gonna Need It
Simplest thingWrite the minimum to pass
No optimizationJust make it work

GREEN Phase Rules

  • Don't write unneeded code
  • Don't optimize yet
  • Pass the test, nothing more

5. REFACTOR Phase Principles

What to Improve

AreaAction
DuplicationExtract common code
NamingMake intent clear
StructureImprove organization
ComplexitySimplify logic

REFACTOR Rules

  • All tests must stay green
  • Small incremental changes
  • Commit after each refactor

6. AAA Pattern

Every test follows:

StepPurpose
ArrangeSet up test data
ActExecute code under test
AssertVerify expected outcome

7. When to Use TDD

ScenarioTDD Value
New featureHigh
Bug fixHigh (write test first)
Complex logicHigh
ExploratoryLow (spike, then TDD)
UI layoutLow

8. Test Prioritization

PriorityTest Type
1Happy path
2Error cases
3Edge cases
4Performance

9. Anti-Patterns

โŒ Don'tโœ… Do
Skip the RED phaseWatch test fail first
Write tests afterWrite tests before
Over-engineer initialKeep it simple
Multiple assertsOne behavior per test
Test implementationTest behavior

10. AI-Augmented TDD

Multi-Agent Pattern

AgentRole
Agent AWrite failing tests (RED)
Agent BImplement to pass (GREEN)
Agent COptimize (REFACTOR)

Remember: The test is the specification. If you can't write a test, you don't understand the requirement.

When to Use

This skill is applicable to execute the workflow or actions described in the overview.

Limitations

  • Use this skill only when the task clearly matches the scope described above.
  • Do not treat the output as a substitute for environment-specific validation, testing, or expert review.
  • Stop and ask for clarification if required inputs, permissions, safety boundaries, or success criteria are missing.