Add test for GH issue #8127

Confirms this bug was the same as #8165

Fixes #8127

packages/react-router/__tests__/gh-issue-8127-test.tsx

@@ -0,0 +1,32 @@
+import * as React from "react";
+import { act, create as createTestRenderer } from "react-test-renderer";
+import { MemoryRouter, Routes, Route } from "react-router-dom";
+
+describe("GH Issue #8127", () => {
+  it("works", () => {
+    let renderer;
+    act(() => {
+      renderer = createTestRenderer(
+        <MemoryRouter initialEntries={["/availability"]}>
+          <Routes>
+            <Route
+              path="*"
+              element={
+                <Routes>
+                  <Route path="*" element={<h1>sub splat</h1>} />
+                  <Route path="availability" element={<h1>availability</h1>} />
+                </Routes>
+              }
+            />
+          </Routes>
+        </MemoryRouter>
+      );
+    });
+
+    expect(renderer.toJSON()).toMatchInlineSnapshot(`
+      <h1>
+        availability
+      </h1>
+    `);
+  });
+});