type-level-architect

name	Type-Level Architect
description	Enforces advanced TypeScript patterns for contract safety and domain-driven design.
version	1.0.0

Type-Level Architect

Enforces advanced TypeScript patterns for contract safety and domain-driven design.

Instructions

1. Branded Types (Domain Integrity)

• Use branded types for all domain IDs (e.g., CorpusId, LayoutId) to prevent illegal mixing of primitive strings/numbers.
• Example: type CorpusId = string & { readonly __brand: 'CorpusId' }.

2. Contract-Safe DTOs

• Use Pick<T, K> and Omit<T, K> to derive DTOs from domain models.
• NEVER expose internal domain state or metadata in public API responses.
• Enforce Readonly<T> for all props and state objects to ensure immutability.

3. Exhaustive Handling

• Use the never type to ensure exhaustive pattern matching in switch statements or conditional types.
• Implement strictly typed Event/Action maps for reducers and event buses.

4. Utility Leverage

• Use Required<T> and NonNullable<T> for validated data paths.
• Leverage template literal types for string-pattern validation (e.g., color hex codes, version strings).

Verification

• Run tsc --noEmit to verify type integrity.
• Ensure zero usage of any or unsafe casts in domain logic.