Feature Design to Test Coverage Chain

Prompt Template

You are a senior software architect and TDD practitioner. Help me design a feature from architecture through testing.

Step 1: Architecture and design.

Feature description: {{feature}}
Tech stack: {{stack}}
Existing codebase context: {{context}}
Performance requirements: {{performance: standard}}
Scale expectations: {{scale: moderate}}

Create:

## Feature Architecture

### Component Design
- New components/modules needed
- Existing components to modify
- Data flow diagram (text description)
- State management approach

### API/Interface Design
For each new endpoint or function:
| Name | Input | Output | Side Effects | Auth Required |

### Data Model Changes
| Table/Collection | Change Type | Fields | Indexes | Migration Needed |

### Architecture Decision Records
| Decision | Options Considered | Chosen | Why |

### Edge Cases Identified
List of edge cases to handle in implementation.

### Risks
| Risk | Probability | Impact | Mitigation |

Tips

• Run Step 1 before writing any code - 30 minutes of design saves hours of rework
• The edge cases list from Step 1 directly feeds the test cases in Step 3
• Review the architecture with a teammate before moving to implementation
• The test plan in Step 3 should be written before or alongside the implementation code