fix some issue and cover by test (#669)

tests/FunctionalTests/Web/WebPageHelpers.cs

@@ -0,0 +1,27 @@
+using System.Text.RegularExpressions;
+
+namespace Microsoft.eShopWeb.FunctionalTests.Web;
+
+public static class WebPageHelpers
+{
+    public static string TokenTag = "__RequestVerificationToken";
+
+    public static string GetRequestVerificationToken(string input)
+    {
+        string regexpression = @"name=""__RequestVerificationToken"" type=""hidden"" value=""([-A-Za-z0-9+=/\\_]+?)""";
+        return RegexSearch(regexpression, input);
+    }
+
+    public static string GetId(string input)
+    {
+        string regexpression = @"name=""Items\[0\].Id"" value=""(\d)""";
+        return RegexSearch(regexpression, input);
+    }
+
+    private static string RegexSearch(string regexpression, string input)
+    {
+        var regex = new Regex(regexpression);
+        var match = regex.Match(input);
+        return match.Groups.Values.LastOrDefault().Value;
+    }
+}