Test that namespace can be deleted in EnC

src/EditorFeatures/CSharpTest/EditAndContinue/ActiveStatementTests.cs

@@ -622,6 +622,28 @@ static void Foo(int a)
             edits.VerifyRudeDiagnostics(active);
         }
 
+        [WpfFact]
+        public void Delete_Entire_Namespace()
+        {
+            string src1 = @"
+namespace N {
+    class C
+    {
+        static void Main(String[] args)
+        {
+            <AS:0>Console.WriteLine(1);</AS:0>
+        }
+    }
+}";
+            string src2 = @"<AS:0></AS:0>";
+
+            var edits = GetTopEdits(src1, src2);
+            var active = GetActiveStatements(src1, src2);
+
+            edits.VerifyRudeDiagnostics(active,
+                Diagnostic(RudeEditKind.Delete, null, "namespace"));
+        }
+
         #endregion
 
         #region Constructors

src/EditorFeatures/Test/EditAndContinue/ActiveStatementDescription.cs

@@ -112,7 +112,8 @@ internal static int[] GetIds(string ids)
                 var ids = GetIds(match.Groups["Id"].Value);
                 int absoluteOffset = offset + markedSyntax.Index;
 
-                yield return ValueTuple.Create(new TextSpan(absoluteOffset, markedSyntax.Length), ids);
+                var span = markedSyntax.Length != 0 ? new TextSpan(absoluteOffset, markedSyntax.Length) : new TextSpan();
+                yield return ValueTuple.Create(span, ids);
 
                 foreach (var nestedSpan in GetSpansRecursive(regex, contentGroupName, markedSyntax.Value, absoluteOffset))
                 {