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prefer-module-level-schema

Declare a Zod schema at module scope when it closes over nothing in the enclosing function

hoistSchema Rule source Tests Catalog JSON

Why

A schema created inside a function is rebuilt on each call. Module scope can enable reuse across callers; local schemas already support local type inference.

Fix

Move the closed schema declaration to module scope and reference it from the function.

Examples

Before — flagged Do not rebuild a closed schema

src/handler.ts

import { z } from "zod";
export function handle(raw: unknown) {
  const ZBody = z.object({ id: z.string(), name: z.string() });
  return ZBody.parse(raw);
}

After — preferred Declare the schema once

src/handler.ts

import { z } from "zod";
const ZBody = z.object({ id: z.string(), name: z.string() });
export function handle(raw: unknown) {
  return ZBody.parse(raw);
}

Options

{
  "additionalProperties": false,
  "properties": {
    "factories": {
      "description": "Zod factory names to check. Defaults to the object-like composites; add `array` / `enum` to widen.",
      "items": { "type": "string" },
      "type": "array"
    },
    "ignoreTestFiles": {
      "description": "Skip test files, where a fixture schema belongs next to its assertion.",
      "type": "boolean"
    },
    "memoCallees": {
      "description": "Wrappers that construct their callback at most once. Defaults to lazy, memo, once, and useMemo.",
      "items": { "type": "string" },
      "type": "array"
    },
    "minProperties": {
      "description": "Minimum key count before an object-like schema is reported.",
      "minimum": 0,
      "type": "number"
    }
  },
  "type": "object"
}