Function stripOuter

packages/zod/src/v4/classic/tests/generics.test.ts:21–30

(schema: TData, data: unknown)

test("generics with optional", () => {
  async function stripOuter<TData extends z.ZodType>(schema: TData, data: unknown) {
    return z
      .object({
        nested: schema.optional(),
      })
      .transform((data) => {
        return data.nested;
      })
      .parse({ nested: data });
  }

  const result = stripOuter(z.object({ a: z.string() }), { a: "asdf" });
  expectTypeOf<typeof result>().toEqualTypeOf<Promise<{ a: string } | undefined>>();