fixed issue #5

frontend/lib/provider/quote_provider.dart

@@ -64,7 +64,7 @@ class QuoteProvider extends ChangeNotifier {
     filterController.text = '';
   }
 
-  Quote randomQuote = Quote(id: 0, author: "dummy", body: "text");
+  late Quote randomQuote;
   bool randomQuoteDeterminator = true;
   String get randomQuoteText { 
     if (randomQuoteDeterminator) {
@@ -80,6 +80,7 @@ class QuoteProvider extends ChangeNotifier {
   }
 
   void nextRandomQuote() {
+    if (filteredQuotes.isEmpty) return;
     final random = Random();
     randomQuote = filteredQuotes[random.nextInt(filteredQuotes.length)];
     notifyListeners();
@@ -107,17 +108,20 @@ class QuoteProvider extends ChangeNotifier {
 
   Future<void> readQuotes() async {
     _loading = true;
-    _error = null;
     notifyListeners();
 
     try {
       _quotes = await repo.readQuotes();
+      populateAuthors();
+
+      if (_quotes.isNotEmpty) {
+        nextRandomQuote();
+      }
+
     } catch (e) {
       _error = e.toString();
     }
 
-    populateAuthors();
-
     _loading = false;
     notifyListeners();
   }