form-validation-with-zod_skill

Overview

This skill enforces the use of Zod for form validation across a JavaScript project. I help teams identify missing or inconsistent validation, suggest Zod-based refactors, and provide clear, actionable guidance to standardize form validation patterns. The focus is practical: safer forms, consistent error handling, and predictable runtime behavior.

How this skill works

I scan form-related code paths and configuration to detect validators, validation libraries, and ad-hoc checks. I flag places that do not use Zod or that use mixed patterns, and I recommend concrete Zod schemas, type-safe bindings, and consistent error mapping. I can produce refactor examples, show how to derive TypeScript types from schemas, and explain why Zod patterns are preferred.

When to use it

• When a project has multiple validation approaches or ad-hoc checks in components or API handlers
• When you want a single source of truth for client and server validation
• When migrating from runtime checks or other libraries to a schema-first approach
• When you need to generate typed interfaces from validation logic
• When you want consistent error shapes for forms and API responses

Best practices

• Define reusable Zod schemas near domain models and import them into forms and handlers
• Derive TypeScript types with z.infer for consistent compile-time types
• Validate at the boundary: validate input server-side and revalidate client-side using the same schema
• Map Zod errors to a uniform error shape for UI display and i18n
• Keep schemas small and composed; prefer z.object + .extend over duplicating rules

Example use cases

• Review a React form that uses manual checks and provide a Zod schema plus example resolver for React Hook Form
• Refactor an Express route that performs ad-hoc validation into a middleware using Zod parsing and typed request handlers
• Create shared schemas for signup and profile update flows so client and server share validation rules
• Audit a codebase and produce a checklist of files to migrate to Zod with concrete migration steps