enum of numbers

This code fails:

import { z } from "zod";

const Multipliers = [1, 2, 3, 4] as const;

const schema = z.enum(Multipliers);

With error

No overload matches this call.
  Overload 1 of 2, '(values: readonly [string, ...string[]]): ZodEnum<[string, ...string[]]>', gave the following error.
    Argument of type '[1, 2, 3, 4, 5, 6]' is not assignable to parameter of type 'readonly [string, ...string[]]'.
      Type at position 0 in source is not compatible with type at position 0 in target.
        Type 'number' is not assignable to type 'string'.
  Overload 2 of 2, '(values: [string, ...string[]]): ZodEnum<[string, ...string[]]>', gave the following error.
    Argument of type '[1, 2, 3, 4, 5, 6]' is not assignable to parameter of type '[string, ...string[]]'.
      Type at position 0 in source is not compatible with type at position 0 in target.
        Type 'number' is not assignable to type 'string'.ts(2769)

Is there any reason why z.enum only expects strings?

https://codesandbox.io/s/zod-number-union-4pqezv

[joshuat]

@colinhacks Would you be open to a PR to add number support to enums? I know it isn’t a 1:1 with the TypeScript definition of an enum, but this is in practice much more akin to a union (that’s even what it infers to) than it is an enum in the TypeScript sense.

[joshuat]

For anyone else running into this problem, this is how I worked around the limitation in z.enum:

import { z } from 'zod';
import type { ZodType } from 'zod';

export const LIMIT_OPTIONS = [10, 25, 50] as const;

export function numericEnum<TValues extends readonly number[]>(
  values: TValues,
) {
  return z.number().superRefine((val, ctx) => {
    if (!values.includes(val)) {
      ctx.addIssue({
        code: z.ZodIssueCode.custom,
        message: `Invalid enum value. Expected ${values.join(
          ' | ',
        )}, received ${val}`,
      });
    }
  }) as ZodType<TValues[number]>;
}

const TestSchema = z.object({
  property: numericEnum(LIMIT_OPTIONS),
});

export type Test = z.infer<typeof TestSchema>;

Playground link