Add namespace comment tests

src/EditorFeatures/CSharpTest/CodeActions/MoveType/MoveTypeTests.MoveScope.cs

-using System.Linq;
-using System.Threading;
+using System.Threading;
 using System.Threading.Tasks;
 using Microsoft.CodeAnalysis.CodeRefactorings.MoveType;
 using Microsoft.CodeAnalysis.Formatting;
@@ -34,6 +33,30 @@ class Class1
             return TestNamespaceMove(code, expected, expectOperation: false);
         }
 
+        [WpfFact, Trait(Traits.Feature, Traits.Features.CodeActionsMoveType)]
+        public Task MoveType_NamespaceScope_SingleItemNamespaceComment()
+        {
+            var code =
+@"// Comment on the namespace
+namespace N1
+{
+    class [||]Class1
+    {
+    }
+}";
+
+            var expected =
+@"// Comment on the namespace
+namespace N1
+{
+    class Class1
+    {
+    }
+}";
+
+            return TestNamespaceMove(code, expected, expectOperation: false);
+        }
+
         [WpfFact, Trait(Traits.Feature, Traits.Features.CodeActionsMoveType)]
         public Task MoveType_NamespaceScope_ItemAtTop()
         {
@@ -57,6 +80,41 @@ class Class1
     }
 }
 
+namespace N1
+{
+    class Class2
+    {
+    }
+}";
+
+            return TestNamespaceMove(code, expected);
+        }
+
+        [WpfFact, Trait(Traits.Feature, Traits.Features.CodeActionsMoveType)]
+        public Task MoveType_NamespaceScope_ItemAtTopNamespaceComment()
+        {
+            var code =
+@"// Comment on the namespace
+namespace N1
+{
+    class [||]Class1
+    {
+    }
+
+    class Class2
+    {
+    }
+}";
+
+            var expected =
+@"// Comment on the namespace
+namespace N1
+{
+    class Class1
+    {
+    }
+}
+
 namespace N1
 {
     class Class2
@@ -172,6 +230,41 @@ class Class1
     }
 }
 
+namespace N1
+{
+    class Class2
+    {
+    }
+}";
+
+            return TestNamespaceMove(code, expected);
+        }
+
+        [WpfFact, Trait(Traits.Feature, Traits.Features.CodeActionsMoveType)]
+        public Task MoveType_NamespaceScope_ItemAtBottomNamespaceComments()
+        {
+            var code =
+@"// Comment on the namespace
+namespace N1
+{
+    class Class1
+    {
+    }
+
+    class [||]Class2
+    {
+    }
+}";
+
+            var expected =
+@"// Comment on the namespace
+namespace N1
+{
+    class Class1
+    {
+    }
+}
+
 namespace N1
 {
     class Class2
@@ -310,6 +403,68 @@ class Class3
     }
 }
 
+namespace N1
+{
+    class Class4
+    {
+    }
+
+    class Class5
+    {
+    }
+}";
+
+            return TestNamespaceMove(code, expected);
+        }
+
+        [WpfFact, Trait(Traits.Feature, Traits.Features.CodeActionsMoveType)]
+        public Task MoveType_NamespaceScope_ItemInMiddleNamespaceComment()
+        {
+            var code =
+@"// Comment on the namespace
+namespace N1
+{
+    class Class1
+    {
+    }
+
+    class Class2
+    {
+    }
+
+    class [||]Class3
+    {
+    }
+
+    class Class4
+    {
+    }
+
+    class Class5
+    {
+    }
+}";
+
+            var expected =
+@"// Comment on the namespace
+namespace N1
+{
+    class Class1
+    {
+    }
+
+    class Class2
+    {
+    }
+}
+
+namespace N1
+{
+    class Class3
+    {
+    }
+}
+
 namespace N1
 {
     class Class4