Adjusted crud tests + added auth tests

app/(tabs)/_layout.tsx

@@ -69,4 +69,4 @@ export default function TabLayout() {
       <Tabs.Screen name="timer" options={{title: "Timer"}} />
     </Tabs>
   );
-}
+}

app/(tabs)/subjects.tsx

@@ -4,13 +4,14 @@ import { Subject } from '@/lib/types';
 import { Session } from '@supabase/supabase-js';
 import { router, Stack, useFocusEffect } from 'expo-router';
 import { useCallback, useEffect, useState } from 'react';
-import { Alert, Pressable, ScrollView, Text, View } from 'react-native';
+import { ActivityIndicator, Alert, Pressable, ScrollView, Text, View } from 'react-native';
 
 import type { SubjectColor } from '@/lib/subjectColors';
 
 export default function Subjects() {
   const [subjects, SetSubjects] = useState<Subject[]>([]);
   const [session, SetSession] = useState<Session | null>(null);
+  const [isLoading, SetIsLoading] = useState(false);
 
   useEffect(() => {
     supabase.auth.getSession().then(({ data }) => {
@@ -29,12 +30,16 @@ export default function Subjects() {
   const GetSubjects = async () => {
     if (!session?.user.id) return;
 
+    SetIsLoading(true);
+
     const { data, error } = await supabase
       .from('subjects')
       .select('*')
       .eq('uId', session.user.id)
       .order('lastChanged', { ascending: false });
 
+    SetIsLoading(false);  
+
     if (error) {
       Alert.alert('Subjects could not be fetched, please try again');
       return;
@@ -51,6 +56,14 @@ export default function Subjects() {
     }, [session])
   );
 
+  if (isLoading) {
+    return (
+      <View className="flex-1 items-center justify-center bg-app-bg">
+        <ActivityIndicator size="large" />
+      </View>
+    );
+  }
+
   return (
     <View className="flex-1 bg-app-bg">
       <Stack.Screen