import { expect, test } from "vitest"; import * as z from "zod/v4"; test("passing validations", () => { const example1 = z.custom((x) => typeof x === "number"); example1.parse(1234); expect(() => example1.parse({})).toThrow(); }); test("string params", () => { const example1 = z.custom((x) => typeof x !== "number", "customerr"); const result = example1.safeParse(1234); expect(result.success).toEqual(false); expect(JSON.stringify(result.error).includes("customerr")).toEqual(true); }); test("instanceof", () => { const fn = (value: string) => Uint8Array.from(Buffer.from(value, "base64")); // Argument of type 'ZodCustom, unknown>' is not assignable to parameter of type '$ZodType>'. z.string().transform(fn).pipe(z.instanceof(Uint8Array)); }); test("non-continuable by default", () => { const A = z .custom((val) => typeof val === "string") .transform((_) => { throw new Error("Invalid input"); }); expect(A.safeParse(123).error!).toMatchInlineSnapshot(` [ZodError: [ { "code": "custom", "path": [], "message": "Invalid input" } ]] `); });