A utility for building runtime enums which can be validated using Zod

RuntimeEnum.ts

import { ZodEnum, z } from "zod";

interface RuntimeEnumT<T extends Readonly<string[]>> {
  // @ts-ignore
  validator: ZodEnum<T>;
  enums: {
    [key in T[number]]: key;
  };
}

/**
 * A utility for building runtime enums which can be validated using Zod
 * Useful for storing enum strings in the database then using them in the frontend
 * @param enums An array containing strings to be used for the enum **as const**
 * @returns Object with enums and associated validator
 * @example ```tsx
 * export const publishedEnum = RuntimeEnum(["published", "draft", "under_review"] as const);
 * console.log(publishedEnum.enums.draft); // Prints "draft"
 *
 * // parse throws an error if it does not match
 * const validated = publishedEnum.validator.parse("testing");
 * console.log(validated); // type: "published" | "draft" | "under_review"
 * ```
 */
export function RuntimeEnum<T extends Readonly<string[]>>(enums: T): RuntimeEnumT<T> {
  // @ts-ignore
  const validator = z.enum(enums);
  const enumObject = {} as { [key in T[number]]: key };

  enums.forEach((enum_name) => {
    enumObject[enum_name as T[number]] = enum_name;
  });

  // @ts-ignore
  return { validator, enums: enumObject };
}

/**
 * A utility type for extracting all possible values for a RuntimeEnum
 * @example
 * ```tsx
 * export const statusEnum = RuntimeEnum(["published", "draft", "under_review"] as const);
 * type StatusEnum = GetRuntimeEnumValues<typeof statusEnum>;
 *                 = "published" | "draft" | "under_review";
 * ```
 */
export type GetRuntimeEnumValues<T> = T extends RuntimeEnumT<infer U> ? U[number] : never;