Fix inertia-page check

Author: skryukov

app/frontend/entrypoints/inertia.ts

@@ -38,25 +38,30 @@ void createInertiaApp({
   },
 
   setup({ el, App, props }) {
-    if (el) {
-      // Uncomment the following to enable SSR hydration:
-      // if (el.hasChildNodes()) {
-      //   hydrateRoot(el, createElement(App, props))
-      //   return
-      // }
-      createRoot(el).render(createElement(App, props))
-    } else {
-      console.error(
-        "Missing root element.\n\n" +
-          "If you see this error, it probably means you load Inertia.js on non-Inertia pages.\n" +
-          'Consider moving <%= vite_typescript_tag "inertia" %> to the Inertia-specific layout instead.',
-      )
-    }
+    // Uncomment the following to enable SSR hydration:
+    // if (el.hasChildNodes()) {
+    //   hydrateRoot(el, createElement(App, props))
+    //   return
+    // }
+    createRoot(el).render(createElement(App, props))
   },
 
   progress: {
     color: "#4B5563",
   },
+}).catch((error) => {
+  // This ensures this entrypoint is only loaded on Inertia pages
+  // by checking for the presence of the root element (#app by default).
+  // Feel free to remove this `catch` if you don't need it.
+  if (document.getElementById("app")) {
+    throw error
+  } else {
+    console.error(
+      "Missing root element.\n\n" +
+        "If you see this error, it probably means you loaded Inertia.js on non-Inertia pages.\n" +
+        'Consider moving <%= vite_typescript_tag "inertia" %> to the Inertia-specific layout instead.',
+    )
+  }
 })
 
 // This will set light / dark mode on load...