JS Skills — Zod Schema, Dayjs & JS Util Patterns

Consistent Zod schema definition rules, dayjs date/time conventions, and guide-driven utility refactoring rules 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

Rule Categories by Priority

Quick Reference

1. Schema Patterns (HIGH)

• schema-naming-convention — Consistent naming for schemas, types, and files
• schema-type-inference — Derive types from schemas with z.infer
• schema-const-enum — Const assertion arrays + z.enum integration
• schema-composition — Compose schemas via nesting, pick, partial
• schema-create-model — Use createModel for instance creation with auto base fields

2. Dayjs Patterns (HIGH)

• dayjs-usage — Plugin setup, timestamp ops, time arithmetic, formatting, duration

3. JS Util Patterns (HIGH)

• js-util-usage — Use upstream llms.txt to discover, apply, and refactor toward @mj-studio/js-util helpers instead of bespoke utility code

How to Use

Read individual rule files for details and examples:

rules/schema-naming-convention.md
rules/schema-type-inference.md
rules/schema-const-enum.md
rules/schema-composition.md
rules/schema-create-model.md
rules/dayjs-usage.md
rules/js-util-usage.md

Each rule file contains:

• Why the rule matters
• Incorrect implementation example
• Correct implementation example
• Reference links