JS Skills — Schema, Dayjs, Util, Module & Structure Patterns

Consistent Zod schema definition rules, dayjs date/time conventions, guide-driven utility refactoring rules, class-based module patterns, Zustand store patterns, and feature-first architecture patterns extracted from production domain modeling.

When to Apply

Reference these guidelines when:

• Defining new domain model schemas with Zod
• Extending base schemas for entity models
• Integrating const assertion enums with Zod validation
• Composing or deriving schemas from existing ones
• Creating model instances with auto-generated base fields
• Setting up dayjs plugins and locale in a project
• Working with timestamps, time arithmetic, formatting, or durations
• Using or reviewing public APIs from @mj-studio/js-util
• Building a stateful module with internal mutable state and related methods
• Creating standard, persisted, or provider-based Zustand stores
• Organizing code by feature folders with feature/{domain} and feature/common for shared pieces