Fix typeHint calculation for zod v4 (#71)

Author: fenok

.yarn/versions/5ff6e18d.yml

@@ -0,0 +1,2 @@
+releases:
+  react-router-typesafe-routes: patch

CHANGELOG.md

@@ -5,6 +5,12 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [Unreleased]
+
+### Fixed
+
+- Zod string formats (e.g. `z.uuid()`) are now properly recognized as strings by the `zod()` helper.
+
 ## [2.2.0] - 2025-07-20
 
 ### Added
@@ -209,6 +215,7 @@ setTypedSearchParams((prevParams) => ({
 - Hook dependencies are now properly listed, which is checked by ESLint. This fixes `useTypedSearchParams` for dynamic routes.
 - Prevent access to internal `useUpdatingRef` helper.
 
+[unreleased]: https://github.com/fenok/react-router-typesafe-routes/tree/dev
 [2.2.0]: https://github.com/fenok/react-router-typesafe-routes/tree/v2.2.0
 [2.1.0]: https://github.com/fenok/react-router-typesafe-routes/tree/v2.1.0
 [2.0.0]: https://github.com/fenok/react-router-typesafe-routes/tree/v2.0.0

src/lib/route.test.ts

@@ -1878,6 +1878,39 @@ it("allows to use zod v4", () => {
   });
 });
 
+it("recognizes zod v4 string formats as strings", () => {
+  const TEST_ROUTE = route({
+    path: "",
+
+    searchParams: {
+      a: zod(z4.uuid()),
+    },
+  });
+
+  assert<
+    IsExact<
+      ReturnType<typeof TEST_ROUTE.$deserializeSearchParams>,
+      {
+        a?: string;
+      }
+    >
+  >(true);
+
+  const plainSearchParams = TEST_ROUTE.$serializeSearchParams({
+    searchParams: {
+      a: "6a5158f2-169a-4fbb-a3f2-0565774e59e4",
+    },
+  });
+
+  expect(urlSearchParamsToRecord(plainSearchParams)).toStrictEqual({
+    a: "6a5158f2-169a-4fbb-a3f2-0565774e59e4",
+  });
+
+  expect(TEST_ROUTE.$deserializeSearchParams(plainSearchParams)).toStrictEqual({
+    a: "6a5158f2-169a-4fbb-a3f2-0565774e59e4",
+  });
+});
+
 it("allows to use zod v3", () => {
   const TEST_ROUTE = route({
     path: "",

src/zod/zod.ts

@@ -1,5 +1,5 @@
 import { type, Type, ParserHint, parser, Parser } from "../lib/index.js";
-import { ZodType, ZodOptional, ZodString, ZodDate, ZodNumber, ZodBoolean } from "zod/v4";
+import { ZodType, ZodOptional } from "zod/v4";
 import {
   ZodType as ZodTypeV3,
   ZodOptional as ZodOptionalV3,
@@ -26,13 +26,25 @@ function configure({ parserFactory }: ConfigureOptions) {
 
     let typeHint: ParserHint = "unknown";
 
-    if (unwrappedZodType instanceof ZodString || unwrappedZodType instanceof ZodStringV3) {
+    if (
+      (unwrappedZodType instanceof ZodType && unwrappedZodType.def.type === "string") ||
+      unwrappedZodType instanceof ZodStringV3
+    ) {
       typeHint = "string";
-    } else if (unwrappedZodType instanceof ZodNumber || unwrappedZodType instanceof ZodNumberV3) {
+    } else if (
+      (unwrappedZodType instanceof ZodType && unwrappedZodType.def.type === "number") ||
+      unwrappedZodType instanceof ZodNumberV3
+    ) {
       typeHint = "number";
-    } else if (unwrappedZodType instanceof ZodBoolean || unwrappedZodType instanceof ZodBooleanV3) {
+    } else if (
+      (unwrappedZodType instanceof ZodType && unwrappedZodType.def.type === "boolean") ||
+      unwrappedZodType instanceof ZodBooleanV3
+    ) {
       typeHint = "boolean";
-    } else if (unwrappedZodType instanceof ZodDate || unwrappedZodType instanceof ZodDateV3) {
+    } else if (
+      (unwrappedZodType instanceof ZodType && unwrappedZodType.def.type === "date") ||
+      unwrappedZodType instanceof ZodDateV3
+    ) {
       typeHint = "date";
     }