Adding more features to restore operation (#420)

* Adding more features to restore operations and added tests

test/Microsoft.SqlTools.ServiceLayer.UnitTests/DisasterRecovery/DatabaseFileInfoTests.cs

@@ -0,0 +1,53 @@
+//
+// Copyright (c) Microsoft. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+//
+
+using System;
+using System.Collections.Generic;
+using System.Text;
+using Microsoft.SqlTools.ServiceLayer.DisasterRecovery.Contracts;
+using Microsoft.SqlTools.ServiceLayer.DisasterRecovery.RestoreOperation;
+using Xunit;
+
+namespace Microsoft.SqlTools.ServiceLayer.UnitTests.DisasterRecovery
+{
+    public class DatabaseFileInfoTests
+    {
+        [Fact]
+        public void DatabaseFileInfoConstructorShouldThrowExceptionGivenNull()
+        {
+            Assert.Throws<ArgumentNullException>(() => new DatabaseFileInfo(null));
+        }
+
+        [Fact]
+        public void DatabaseFileInfoShouldReturnNullGivenEmptyProperties()
+        {
+            LocalizedPropertyInfo[] properties = new LocalizedPropertyInfo[] { };
+            var fileInfo = new DatabaseFileInfo(properties);
+            Assert.True(string.IsNullOrEmpty(fileInfo.Id));
+            Assert.True(string.IsNullOrEmpty(fileInfo.GetPropertyValueAsString(BackupSetInfo.BackupComponentPropertyName)));
+        }
+
+        [Fact]
+        public void DatabaseFileInfoShouldReturnValuesGivenValidProperties()
+        {
+            LocalizedPropertyInfo[] properties = new LocalizedPropertyInfo[] {
+                new LocalizedPropertyInfo
+                { 
+                    PropertyName = "name",
+                    PropertyValue = 1
+                },
+                new LocalizedPropertyInfo
+                {
+                    PropertyName = DatabaseFileInfo.IdPropertyName,
+                    PropertyValue = "id"
+                }
+
+            };
+            var fileInfo = new DatabaseFileInfo(properties);
+            Assert.Equal(fileInfo.Id, "id");
+            Assert.Equal(fileInfo.GetPropertyValueAsString("name"), "1");
+        }
+    }
+}