Preserve trivia when converting a numeric literal base

src/EditorFeatures/CSharpTest/CodeActions/ConvertNumericLiteral/ConvertNumericLiteralTests.cs

@@ -26,7 +26,7 @@ private async Task TestFixOneAsync(string initial, string expected, Refactoring
             await TestInRegularAndScriptAsync(CreateTreeText("[||]" + initial), CreateTreeText(expected), index: (int)refactoring);
         }
 
-        private string CreateTreeText(string initial)
+        private static string CreateTreeText(string initial)
         {
             return @"class X { void F() { var x = " + initial + @"; } }";
         }
@@ -96,5 +96,30 @@ public async Task TestTypeCharacter()
         {
             await TestFixOneAsync("0x1e5UL", "0b111100101UL", Refactoring.ChangeBase2);
         }
+
+        [WorkItem(19225, "https://github.com/dotnet/roslyn/issues/19225")]
+        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsConvertNumericLiteral)]
+        public async Task TestPreserveWhitespaces()
+        {
+            await TestInRegularAndScriptAsync(
+@"class Program
+{
+    void M()
+    {
+        var numbers = new int[] {
+            [||]0x1, 0x2
+        };
+    }
+}",
+@"class Program
+{
+    void M()
+    {
+        var numbers = new int[] {
+            0b1, 0x2
+        };
+    }
+}", index: (int)Refactoring.ChangeBase2, ignoreTrivia: false);
+        }
     }
 }

src/EditorFeatures/VisualBasicTest/CodeActions/ConvertNumericLiteral/ConvertNumericLiteralTests.vb

@@ -26,7 +26,7 @@ Namespace Microsoft.CodeAnalysis.Editor.VisualBasic.UnitTests.CodeActions.Conver
             Await TestInRegularAndScriptAsync(CreateTreeText("[||]" + initial), CreateTreeText(expected), index:=DirectCast(refactoring, Integer))
         End Function
 
-        Private Function CreateTreeText(initial As String) As String
+        Private Shared Function CreateTreeText(initial As String) As String
             Return "
 Class X
     Sub M()
@@ -89,5 +89,27 @@ End Class"
         Public Async Function TestTypeCharacter() As Task
             Await TestFixOneAsync("&H1e5UL", "&B111100101UL", Refactoring.ChangeBase2)
         End Function
+
+        <WorkItem(19225, "https://github.com/dotnet/roslyn/issues/19225")>
+        <Fact, Trait(Traits.Feature, Traits.Features.CodeActionsConvertNumericLiteral)>
+        Public Async Function TestPreserveTrivia() As Task
+            Await TestInRegularAndScriptAsync(
+"Class X
+    Sub M()
+        Dim x As Integer() =
+        {
+            [||]&H1, &H2
+        }
+    End Sub
+End Class",
+"Class X
+    Sub M()
+        Dim x As Integer() =
+        {
+            &B1, &H2
+        }
+    End Sub
+End Class", index:=Refactoring.ChangeBase2, ignoreTrivia:=False)
+        End Function
     End Class
 End Namespace

src/Features/Core/Portable/ConvertNumericLiteral/AbstractConvertNumericLiteralCodeRefactoringProvider.cs

@@ -114,7 +114,8 @@ void RegisterRefactoringWithResult(string text, string title)
                 context.RegisterRefactoring(new MyCodeAction(title, c =>
                 {
                     var generator = SyntaxGenerator.GetGenerator(document);
-                    var updatedToken = generator.NumericLiteralToken(text + suffix, (ulong)value);
+                    var updatedToken = generator.NumericLiteralToken(text + suffix, (ulong)value)
+                        .WithTriviaFrom(numericToken);
                     var updatedRoot = root.ReplaceToken(numericToken, updatedToken);
                     return Task.FromResult(document.WithSyntaxRoot(updatedRoot));
                 }));