next-type-design-analyzer

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name: next-type-design-analyzer description: Analyze type design quality and invariants. Use when introducing new types, during PR creation with data models, or when refactoring type designs.

This skill analyzes type designs to ensure strong, clearly expressed invariants and well-encapsulated interfaces.

Context to Gather

Before analyzing, read:

• The type definitions being reviewed
• Related types and their relationships
• How the types are used throughout the codebase
• Existing type patterns in the project

Core Mission

Evaluate type designs with a critical eye toward invariant strength, encapsulation quality, and practical usefulness. Well-designed types are the foundation of maintainable, bug-resistant software systems.

Analysis Framework

When analyzing a type:

1. Identify Invariants

Examine the type to identify all implicit and explicit invariants:

• Data consistency requirements
• Valid state transitions
• Relationship constraints between fields
• Business logic rules encoded in the type
• Preconditions and postconditions

2. Evaluate Encapsulation (Rate 1-10)

• Are internal implementation details properly hidden?
• Can the type's invariants be violated from outside?
• Are there appropriate access modifiers?
• Is the interface minimal and complete?

3. Assess Invariant Expression (Rate 1-10)

• How clearly are invariants communicated through the type's structure?
• Are invariants enforced at compile-time where possible?
• Is the type self-documenting through its design?
• Are edge cases and constraints obvious from the type definition?

4. Judge Invariant Usefulness (Rate 1-10)

• Do the invariants prevent real bugs?
• Are they aligned with business requirements?
• Do they make the code easier to reason about?
• Are they neither too restrictive nor too permissive?

5. Examine Invariant Enforcement (Rate 1-10)

• Are invariants checked at construction time?
• Are all mutation points guarded?
• Is it impossible to create invalid instances?
• Are runtime checks appropriate and comprehensive?

Output Format

Copy## Type: [TypeName]

### Invariants Identified
- [List each invariant with a brief description]

### Ratings
- **Encapsulation**: X/10
  [Brief justification]

- **Invariant Expression**: X/10
  [Brief justification]

- **Invariant Usefulness**: X/10
  [Brief justification]

- **Invariant Enforcement**: X/10
  [Brief justification]