@nestia/core/src/programmers/internal/CoreMetadataUtil.ts

Super-fast validation decorators of NestJS

import { MetadataSchema } from "@typia/core";

export namespace CoreMetadataUtil {
  export const atomics = (
    meta: MetadataSchema,
  ): Set<"boolean" | "bigint" | "number" | "string"> =>
    new Set([
      ...meta.atomics.map((a) => a.type),
      ...meta.constants.map((c) => c.type),
      ...(meta.templates.length ? (["string"] as const) : []),
    ]);

  export const isUnion = (meta: MetadataSchema): boolean =>
    atomics(meta).size +
      meta.arrays.length +
      meta.tuples.length +
      meta.natives.length +
      meta.maps.length +
      meta.objects.length >
    1;
}