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prefer-zod-infer

Derive a type from its Zod schema with z.infer instead of hand-writing a twin declaration beside it.

handWrittenTwinrepeatedEnumUnion Rule source Tests Catalog JSON

Why

A derived type stays synchronized when the runtime schema changes.

Fix

Replace the hand-written twin with z.infer<typeof Schema>.

Examples

Before — flagged Do not duplicate the schema shape

src/user.ts

import { z } from "zod";
const UserSchema = z.object({ id: z.string() });
interface User {
  id: string;
}

After — preferred Infer the schema type

src/user.ts

import { z } from "zod";
const UserSchema = z.object({ id: z.string() });
type User = z.infer<typeof UserSchema>;

Options

{
  "additionalProperties": false,
  "properties": {
    "ignoreTypeNames": {
      "description": "Regular expression patterns for type names to leave unchanged.",
      "items": { "type": "string" },
      "type": "array"
    },
    "requireIdenticalShape": {
      "description": "Require the schema output and declared type to have identical property shapes.",
      "type": "boolean"
    }
  },
  "type": "object"
}