Guides the development process using the strict Test-Driven Development (TDD) cycle.

Install

mkdir -p .claude/skills/tdd-workflow-javiertarazon && curl -L -o skill.zip "https://agentskills.codes/api/skills/download/15136" && unzip -o skill.zip -d .claude/skills/tdd-workflow-javiertarazon && rm skill.zip

Installs to .claude/skills/tdd-workflow-javiertarazon

Activation

This is the description your AI agent reads to decide when to run this skill — the better it matches your request, the more reliably it fires.

Test-Driven Development workflow principles. RED-GREEN-REFACTOR cycle.
70 charsno explicit “when” trigger
Beginner

Key capabilities

  • Write failing tests first (RED phase)
  • Implement minimal code to pass tests (GREEN phase)
  • Refactor code to improve quality (REFACTOR phase)
  • Apply the AAA pattern for test structure
  • Prioritize test cases (happy path, error, edge cases)
  • Identify TDD anti-patterns

How it works

The skill guides through the RED-GREEN-REFACTOR cycle, starting with writing a failing test, then implementing the minimum code to make it pass, and finally refactoring the code.

Inputs & outputs

You give it
feature requirement or bug description
You get back
failing test, passing code, and refactored code

When to use tdd-workflow

  • Practicing TDD during development
  • Refactoring code while maintaining tests
  • Ensuring test coverage for new features

About this skill

TDD Workflow

Write tests first, code second.


1. The TDD Cycle

🔴 RED → Write failing test
    ↓
🟢 GREEN → Write minimal code to pass
    ↓
🔵 REFACTOR → Improve code quality
    ↓
   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

❌ Don't✅ 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.

When not to use it

  • The task is exploratory development
  • The task involves UI layout

Limitations

  • The skill is not suitable for exploratory development
  • It is not designed for UI layout tasks

How it compares

This skill enforces a structured, iterative development process by dictating the order of test writing, code implementation, and refactoring, unlike an unstructured coding approach.

Compared to similar skills

tdd-workflow side by side with the closest alternatives in the catalog.

SkillInstallsUpdatedSafetyDifficulty
tdd-workflow (this skill)05moNo flagsBeginner
code-assist15moNo flagsAdvanced
moonbit-agent-guide17moReviewIntermediate
ruby-pro14moNo flagsAdvanced

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