Consider Brands for Nominal Typing

Overview

Add phantom types to distinguish semantically different values.

TypeScript uses structural typing, but sometimes you need nominal typing - values that are distinct because you SAY they are, not because they have different shapes. Brands let you do this without runtime overhead.

When to Use This Skill

• Distinguishing paths (absolute vs relative)
• Attaching units to numbers (meters, seconds)
• Preventing 2D/3D vector mix-ups
• Marking validated/sanitized strings
• Creating type-safe identifiers

The Iron Rule