tdd-workflow
Test-Driven Development workflow principles. RED-GREEN-REFACTOR cycle.
Installation
Details
Usage
After installing, this skill will be available to your AI coding assistant.
Verify installation:
skills listSkill Instructions
name: tdd-workflow description: Test-Driven Development workflow principles. RED-GREEN-REFACTOR cycle.
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
- Write production code only to make a failing test pass
- Write only enough test to demonstrate failure
- Write only enough code to make the test pass
3. RED Phase Principles
What to Write
| Focus | Example |
|---|---|
| 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
| Principle | Meaning |
|---|---|
| YAGNI | You Aren't Gonna Need It |
| Simplest thing | Write the minimum to pass |
| No optimization | Just 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
| Area | Action |
|---|---|
| Duplication | Extract common code |
| Naming | Make intent clear |
| Structure | Improve organization |
| Complexity | Simplify logic |
REFACTOR Rules
- All tests must stay green
- Small incremental changes
- Commit after each refactor
6. AAA Pattern
Every test follows:
| Step | Purpose |
|---|---|
| Arrange | Set up test data |
| Act | Execute code under test |
| Assert | Verify expected outcome |
7. When to Use TDD
| Scenario | TDD Value |
|---|---|
| New feature | High |
| Bug fix | High (write test first) |
| Complex logic | High |
| Exploratory | Low (spike, then TDD) |
| UI layout | Low |
8. Test Prioritization
| Priority | Test Type |
|---|---|
| 1 | Happy path |
| 2 | Error cases |
| 3 | Edge cases |
| 4 | Performance |
9. Anti-Patterns
| ❌ Don't | ✅ Do |
|---|---|
| Skip the RED phase | Watch test fail first |
| Write tests after | Write tests before |
| Over-engineer initial | Keep it simple |
| Multiple asserts | One behavior per test |
| Test implementation | Test behavior |
10. AI-Augmented TDD
Multi-Agent Pattern
| Agent | Role |
|---|---|
| Agent A | Write failing tests (RED) |
| Agent B | Implement to pass (GREEN) |
| Agent C | Optimize (REFACTOR) |
Remember: The test is the specification. If you can't write a test, you don't understand the requirement.
More by xenitV1
View allAPI design principles and decision-making. REST vs GraphQL vs tRPC selection, response formats, versioning, pagination. Teaches thinking, not fixed patterns.
Defines different operational modes for AI behavior. Each mode optimizes for specific scenarios like brainstorming, implementation, or debugging.
Database design principles and decision-making. Schema design, indexing strategy, ORM selection, serverless databases. Teaches thinking, not fixed SQL.
Mobile-first design thinking and decision-making for iOS and Android apps. Touch interaction, performance patterns, platform conventions. Teaches principles, not fixed values. Use when building React Native, Flutter, or native mobile apps.