From 3a46297ddf46270c8379ad0ba336ccecfde51f9a Mon Sep 17 00:00:00 2001
From: Patrik Oldsberg <poldsberg@gmail.com>
Date: Mon, 22 Jan 2024 13:42:41 +0100
Subject: [PATCH] app: fix auth entry point redirect

Signed-off-by: Patrik Oldsberg <poldsberg@gmail.com>
---
 packages/app/src/auth.tsx | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/packages/app/src/auth.tsx b/packages/app/src/auth.tsx
index e06df51754..9e5f89b4c2 100644
--- a/packages/app/src/auth.tsx
+++ b/packages/app/src/auth.tsx
@@ -28,9 +28,20 @@ import {
   configApiRef,
   createApiFactory,
   discoveryApiRef,
+  useApi,
 } from '@backstage/core-plugin-api';
 import { AuthProxyDiscoveryApi } from '../src/AuthProxyDiscoveryApi';
 
+// TODO(Rugvip): make this available via some util, or maybe Utility API?
+function readBasePath(configApi: typeof configApiRef.T) {
+  let { pathname } = new URL(
+    configApi.getOptionalString('app.baseUrl') ?? '/',
+    'http://sample.dev', // baseUrl can be specified as just a path
+  );
+  pathname = pathname.replace(/\/*$/, '');
+  return pathname;
+}
+
 const app = createApp({
   apis: [
     createApiFactory({
@@ -54,7 +65,7 @@ const app = createApp({
 });
 
 function RedirectToRoot() {
-  window.location.pathname += '/..';
+  window.location.pathname = readBasePath(useApi(configApiRef));
   return <div />;
 }