Add more test cases for code coverage (#127)

Next round of code coverage test cases.  Please review the commit for next iteration.

* Add connection retry tests

* More test coverage

* Update diagnostics end-to-end test

test/Microsoft.SqlTools.ServiceLayer.Test/QueryExecution/DataStorage/StorageDataReaderTests.cs

@@ -0,0 +1,87 @@
+//
+// Copyright (c) Microsoft. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+//
+
+#if LIVE_CONNECTION_TESTS
+
+using System.Data.Common;
+using Microsoft.SqlTools.ServiceLayer.Connection;
+using Microsoft.SqlTools.ServiceLayer.QueryExecution.DataStorage;
+using Microsoft.SqlTools.ServiceLayer.Workspace.Contracts;
+using Microsoft.SqlTools.Test.Utility;
+using Xunit;
+
+namespace Microsoft.SqlTools.ServiceLayer.Test.QueryExecution.DataStorage
+{
+    public class StorageDataReaderTests
+    {
+        private StorageDataReader GetTestStorageDataReader(out DbDataReader reader, string query)
+        {
+            ScriptFile scriptFile;
+            ConnectionInfo connInfo = TestObjects.InitLiveConnectionInfo(out scriptFile);
+
+            var command = connInfo.SqlConnection.CreateCommand();
+            command.CommandText = query;
+            reader = command.ExecuteReader();
+
+            return new StorageDataReader(reader);
+        }
+
+        /// <summary>
+        /// Validate GetBytesWithMaxCapacity
+        /// </summary>
+        [Fact]
+        public void GetBytesWithMaxCapacityTest()
+        {
+            DbDataReader reader;
+            var storageReader = GetTestStorageDataReader(
+                out reader,
+                "SELECT CAST([name] as TEXT) As TextName FROM sys.all_columns");
+
+            reader.Read();
+            Assert.False(storageReader.IsDBNull(0));
+
+            byte[] bytes = storageReader.GetBytesWithMaxCapacity(0, 100);
+            Assert.NotNull(bytes);
+        }
+
+        /// <summary>
+        /// Validate GetCharsWithMaxCapacity
+        /// </summary>
+        [Fact]
+        public void GetCharsWithMaxCapacityTest()
+        {
+            DbDataReader reader;
+            var storageReader = GetTestStorageDataReader(
+                out reader,
+                "SELECT name FROM sys.all_columns");
+
+            reader.Read();
+            Assert.False(storageReader.IsDBNull(0));
+
+            string shortName = storageReader.GetCharsWithMaxCapacity(0, 2);
+            Assert.True(shortName.Length == 2);
+        }
+
+        /// <summary>
+        /// Validate GetXmlWithMaxCapacity
+        /// </summary>
+        [Fact]
+        public void GetXmlWithMaxCapacityTest()
+        {
+            DbDataReader reader;
+            var storageReader = GetTestStorageDataReader(
+                out reader,
+                "SELECT CAST('<xml>Test XML context</xml>' AS XML) As XmlColumn");
+
+            reader.Read();
+            Assert.False(storageReader.IsDBNull(0));
+
+            string shortXml = storageReader.GetXmlWithMaxCapacity(0, 2);
+            Assert.True(shortXml.Length == 3);
+        }
+    }
+}
+
+#endif