feat(typescript): add branded type for creating routes

src/js/index.d.ts

@@ -23,6 +23,11 @@ type RouteName = KnownRouteName | (string & {});
 // which would prevent intellisense from autocompleting known route names.
 // See https://stackoverflow.com/a/61048124/6484459.
 
+/**
+ * A generated route URL string.
+ */
+export type RouteUrl = string;
+
 /**
  * A valid route name to pass to `route()` to generate a URL.
  */
@@ -201,14 +206,14 @@ export function route<T extends ValidRouteName>(
     params?: RouteParams<T> | undefined,
     absolute?: boolean,
     config?: Config,
-): string;
+): RouteUrl;
 
 export function route<T extends ValidRouteName>(
     name: T,
     params?: ParameterValue | undefined,
     absolute?: boolean,
     config?: Config,
-): string;
+): RouteUrl;
 
 /**
  * Ziggy's Vue plugin.

tests/js/route.test-d.ts

@@ -1,5 +1,5 @@
 import { assertType } from 'vitest';
-import { Config, route, Router } from '../../src/js';
+import { Config, route, Router, RouteUrl } from '../../src/js';
 
 // Add generated routes to use for testing inside this file. In a real app these declarations
 // would be in a separate file generated by running `php artisan ziggy:generate --types`.
@@ -111,6 +111,7 @@ assertType(route().current('posts.comments.show', 'foo'));
 // Test route function return types
 assertType<string>(route('optional', { maybe: 'foo' }));
 assertType<string>(route('optional', 'foo'));
+assertType<RouteUrl>(route('posts.comments.show', 'foo'));
 assertType<Router>(route(undefined, undefined, undefined, {} as Config));
 
 // Uncomment to test strict route name checking - invalid route names in this file should error