feat: allow path on index routes

packages/react-router/__tests__/index-routes-test.tsx

@@ -1,4 +1,6 @@
-import { matchRoutes } from "react-router";
+import * as React from "react";
+import { create as createTestRenderer } from "react-test-renderer";
+import { matchRoutes, MemoryRouter, Routes, Route, Outlet } from "react-router";
 
 describe("index route matching", () => {
   it("throws when the index route has children", () => {
@@ -21,4 +23,38 @@ describe("index route matching", () => {
       );
     }).toThrow("must not have child routes");
   });
+
+  it("matches path on index route", () => {
+    let renderer = createTestRenderer(
+      <MemoryRouter initialEntries={["/users"]}>
+        <Routes>
+          <Route index path="users" element={<h1>Users</h1>} />
+        </Routes>
+      </MemoryRouter>
+    );
+
+    expect(renderer.toJSON()).toMatchInlineSnapshot(`
+      <h1>
+        Users
+      </h1>
+    `);
+  });
+
+  it("throws when the index route with path has children", () => {
+    expect(() => {
+      matchRoutes(
+        [
+          {
+            path: "/users",
+            index: true,
+            children: [
+              // This config is not valid because index routes cannot have children
+              { path: ":id" }
+            ]
+          }
+        ],
+        "/users/mj"
+      );
+    }).toThrow("must not have child routes");
+  });
 });

packages/react-router/index.tsx

@@ -211,8 +211,10 @@ export interface LayoutRouteProps {
 }
 
 export interface IndexRouteProps {
+  caseSensitive?: boolean;
   element?: React.ReactElement | null;
   index: true;
+  path?: string;
 }
 
 /**