inertia

---

name: inertia description: Guidelines for Rails/Inertia projects with React and Zod. Use when working with Inertia.js or Rails frontend components.

Zod Schemas for Props

Use .nullish() instead of .nullable() for optional fields in Zod schemas. Rails/Inertia can return either null or undefined for missing values, and .nullish() handles both:

// Good - handles both null and undefined
const PropsSchema = z.object({
  name: z.string(),
  description: z.string().nullish(),  // string | null | undefined
})

// Bad - only handles null, will fail on undefined
const PropsSchema = z.object({
  name: z.string(),
  description: z.string().nullable(),  // string | null (undefined throws)
})