fix(router-core): consider __root__ in path parsing of trailing underscores (#5262)

Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>

Author: nlynzaad

e2e/react-start/basic/package.json

@@ -8,7 +8,9 @@
     "dev:e2e": "vite dev",
     "build": "vite build && tsc --noEmit",
     "start": "pnpx srvx --prod -s ../client  dist/server/server.js",
-    "test:e2e": "rm -rf port*.txt; playwright test --project=chromium"
+    "test:e2e:spaMode": "rm -rf port*.txt; MODE=spa playwright test --project=chromium",
+    "test:e2e:ssrMode": "rm -rf port*.txt; playwright test --project=chromium",
+    "test:e2e": "pnpm run test:e2e:spaMode && pnpm run test:e2e:ssrMode"
   },
   "dependencies": {
     "@tanstack/react-router": "workspace:^",

e2e/react-start/basic/playwright.config.ts

@@ -3,19 +3,22 @@ import {
   getDummyServerPort,
   getTestServerPort,
 } from '@tanstack/router-e2e-utils'
+import { isSpaMode } from 'tests/utils/isSpaMode'
 import packageJson from './package.json' with { type: 'json' }
 
 const PORT = await getTestServerPort(packageJson.name)
 const EXTERNAL_PORT = await getDummyServerPort(packageJson.name)
 const baseURL = `http://localhost:${PORT}`
+const spaModeCommand = `pnpm build && pnpm dev:e2e --port=${PORT}`
+const ssrModeCommand = `pnpm build && pnpm start`
 
+console.log('running in spa mode: ', isSpaMode.toString())
 /**
  * See https://playwright.dev/docs/test-configuration.
  */
 export default defineConfig({
   testDir: './tests',
   workers: 1,
-
   reporter: [['line']],
 
   globalSetup: './tests/setup/global.setup.ts',
@@ -27,16 +30,25 @@ export default defineConfig({
   },
 
   webServer: {
-    command: `VITE_NODE_ENV="test" VITE_EXTERNAL_PORT=${EXTERNAL_PORT} pnpm build && VITE_NODE_ENV="test" VITE_EXTERNAL_PORT=${EXTERNAL_PORT} VITE_SERVER_PORT=${PORT} PORT=${PORT} pnpm start`,
+    command: isSpaMode ? spaModeCommand : ssrModeCommand,
     url: baseURL,
     reuseExistingServer: !process.env.CI,
     stdout: 'pipe',
+    env: {
+      MODE: process.env.MODE || '',
+      VITE_NODE_ENV: 'test',
+      VITE_EXTERNAL_PORT: String(EXTERNAL_PORT),
+      VITE_SERVER_PORT: String(PORT),
+      PORT: String(PORT),
+    },
   },
 
   projects: [
     {
       name: 'chromium',
-      use: { ...devices['Desktop Chrome'] },
+      use: {
+        ...devices['Desktop Chrome'],
+      },
     },
   ],
 })