Fixes #1

Author: Odotocodot

Constants.cs

@@ -7,7 +7,8 @@ public static class Constants
         public const string SyncIconPath = "Images/refresh.png";
         public const string RecentIconPath = "Images/recent.png";
         public const string RecentPageIconPath = "Images/recent_page.png";
-
+        public const string WarningLogoPath = "Images/warning.png";
+        
         public const string StructureKeyword = "nb:\\";
         public const string RecentKeyword = "rcntpgs:";
     }

Images/warning.png

@@ -112,6 +112,17 @@ public List<Result> Query(Query query)
             if (query.FirstSearch.StartsWith(Constants.StructureKeyword))
                 return notebookExplorer.Explore(query);
 
+            //Check for invalid start of query i.e. symbols
+            if (!char.IsLetterOrDigit(query.Search[0]))
+                return new List<Result>()
+                {
+                    new Result
+                    {
+                        Title = "Invalid query",
+                        SubTitle = "The first character of the search must be a letter or a digit",
+                        IcoPath = Constants.WarningLogoPath,
+                    }
+                };
             //Default search 
             var searches = OneNoteProvider.FindPages(query.Search)
                 .Select(pg => rc.CreatePageResult(pg, context.API.FuzzySearch(query.Search, pg.Name).MatchData));