fix: update useBlocker behavior and eslint config for 404 page handling

Author: jiji-hoon96

packages/react-router/eslint.config.ts

@@ -19,6 +19,7 @@ export default [
       '@eslint-react/dom/no-missing-button-type': 'off',
       'react-hooks/exhaustive-deps': 'error',
       'react-hooks/rules-of-hooks': 'error',
+      '@typescript-eslint/no-unnecessary-condition': 'off',
     },
   },
 ]

packages/react-router/src/useBlocker.tsx

@@ -185,7 +185,7 @@ export function useBlocker(
             routeId: '__notFound__',
             fullPath: pathname,
             pathname: pathname,
-            params: matchedRoutes.routeParams || {},
+            params: matchedRoutes.routeParams,
             search: router.options.parseSearch(location.search),
           }
         }

packages/react-router/tests/useBlocker.test.tsx

@@ -444,7 +444,7 @@ describe('useBlocker', () => {
 
   test('should allow navigation from 404 page when blocker is active', async () => {
     const rootRoute = createRootRoute({
-      notFoundComponent: () => {
+      notFoundComponent: function NotFoundComponent() {
         const navigate = useNavigate()
 
         useBlocker({ shouldBlockFn: () => true })
@@ -512,7 +512,7 @@ describe('useBlocker', () => {
 
   test('should handle blocker navigation from 404 to another 404', async () => {
     const rootRoute = createRootRoute({
-      notFoundComponent: () => {
+      notFoundComponent: function NotFoundComponent() {
         const navigate = useNavigate()
 
         useBlocker({ shouldBlockFn: () => true })