From 1c00e2590199bbf571c70c074f8bf1484ed18bab Mon Sep 17 00:00:00 2001
From: Patrik Oldsberg <poldsberg@gmail.com>
Date: Mon, 16 Mar 2026 19:09:55 +0100
Subject: [PATCH] Preserve app loading fallback in createDevApp.

Only suspend the lazy BUI CSS import so the app root keeps its built-in loading UI, and lock that behavior down in the mocked render test.

Signed-off-by: Patrik Oldsberg <poldsberg@gmail.com>
Made-with: Cursor
---
 packages/frontend-dev-utils/src/createDevApp.test.tsx | 5 +++++
 packages/frontend-dev-utils/src/createDevApp.tsx      | 8 +++++---
 2 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/packages/frontend-dev-utils/src/createDevApp.test.tsx b/packages/frontend-dev-utils/src/createDevApp.test.tsx
index 6624681152..5c0b21ab25 100644
--- a/packages/frontend-dev-utils/src/createDevApp.test.tsx
+++ b/packages/frontend-dev-utils/src/createDevApp.test.tsx
@@ -134,6 +134,11 @@ describe('createDevApp', () => {
       });
       expect(createRoot).toHaveBeenCalledWith(root);
     });
+
+    const renderedNode = render.mock.calls[0][0] as any;
+    expect(renderedNode.props.children).toHaveLength(2);
+    expect(renderedNode.props.children[0].props.fallback).toBeNull();
+    expect(renderedNode.props.children[1].props.children).toBe('Test App Root');
   });
 
   it('should throw a clear error when the root element is missing', () => {
diff --git a/packages/frontend-dev-utils/src/createDevApp.tsx b/packages/frontend-dev-utils/src/createDevApp.tsx
index 112901ed52..80cc95dc22 100644
--- a/packages/frontend-dev-utils/src/createDevApp.tsx
+++ b/packages/frontend-dev-utils/src/createDevApp.tsx
@@ -108,10 +108,12 @@ export function createDevApp(options: CreateDevAppOptions): void {
 
   ReactDOMPromise.then(ReactDOM => {
     const rootNode = (
-      <Suspense fallback={null}>
-        <BuiCss />
+      <>
+        <Suspense fallback={null}>
+          <BuiCss />
+        </Suspense>
         {AppRoot}
-      </Suspense>
+      </>
     );
 
     if ('createRoot' in ReactDOM) {