Add test for GenerateUniqueName, revert 1 change

src/VisualStudio/Core/Def/Implementation/TaskList/AbstractVisualStudioErrorTaskList.TaskItem.cs

@@ -98,7 +98,7 @@ private int InfoCompareTo(IErrorTaskItem left, IErrorTaskItem right)
             {
                 if (left.DocumentId == null && right.DocumentId == null)
                 {
-                    return string.Compare(left.Message, right.Message, StringComparison.Ordinal);
+                    return string.Compare(left.Message, right.Message);
                 }
 
                 Contract.Requires(left.DocumentId != null && right.DocumentId != null);
@@ -114,7 +114,7 @@ private int InfoCompareTo(IErrorTaskItem left, IErrorTaskItem right)
                     return column;
                 }
 
-                return string.Compare(left.Message, right.Message, StringComparison.Ordinal);
+                return string.Compare(left.Message, right.Message);
             }
 
             private int NullCompareTo(object left, object right)

src/Workspaces/CoreTest/WorkspaceTests/AdhocWorkspaceTests.cs

@@ -8,6 +8,8 @@
 using System.Threading;
 using System.Threading.Tasks;
 using Xunit;
+using Microsoft.CodeAnalysis.Shared.Utilities;
+using System;
 
 namespace Microsoft.CodeAnalysis.UnitTests
 {
@@ -327,5 +329,24 @@ public void TestOpenCloseAdditionalDocument()
                 Assert.Equal(false, doc.TryGetText(out currentText));
             }
         }
+
+        [Fact]
+        public void TestGenerateUniqueName()
+        {
+            var a = NameGenerator.GenerateUniqueName("ABC", "txt", _ => true);
+            Assert.True(a.StartsWith("ABC", StringComparison.Ordinal));
+            Assert.True(a.EndsWith(".txt", StringComparison.Ordinal));
+            Assert.False(a.EndsWith("..txt", StringComparison.Ordinal));
+
+            var b = NameGenerator.GenerateUniqueName("ABC", ".txt", _ => true);
+            Assert.True(b.StartsWith("ABC", StringComparison.Ordinal));
+            Assert.True(b.EndsWith(".txt", StringComparison.Ordinal));
+            Assert.False(b.EndsWith("..txt", StringComparison.Ordinal));
+
+            var c = NameGenerator.GenerateUniqueName("ABC", "\u0640.txt", _ => true);
+            Assert.True(c.StartsWith("ABC", StringComparison.Ordinal));
+            Assert.True(c.EndsWith(".\u0640.txt", StringComparison.Ordinal));
+            Assert.False(c.EndsWith("..txt", StringComparison.Ordinal));
+        }
     }
 }