Simplify

src/EditorFeatures/TestUtilities/CodeActions/AbstractCodeActionOrUserDiagnosticTest.cs

@@ -445,9 +445,9 @@ protected Task TestSmartTagGlyphTagsAsync(string initialMarkup, ImmutableArray<s
             string diagnosticTag,
             string markupKey,
             string initialMarkupWithoutSpans,
-            List<Diagnostic> diagnosticsWithTag)
+            ImmutableArray<Diagnostic> diagnosticsWithTag)
         {
-            var message = $"Expected {expectedSpans.Length} diagnostic spans with custom tag '{diagnosticTag}', but there were {diagnosticsWithTag.Count}.";
+            var message = $"Expected {expectedSpans.Length} diagnostic spans with custom tag '{diagnosticTag}', but there were {diagnosticsWithTag.Length}.";
 
             if (expectedSpans.Length == 0)
             {

src/Features/Core/Portable/SimplifyInterpolation/AbstractSimplifyInterpolationCodeFixProvider.cs

@@ -89,11 +89,11 @@ public override Task RegisterCodeFixesAsync(CodeFixContext context)
                     (TInterpolationAlignmentClause)generator.InterpolationAlignmentClause(alignment));
             }
 
-            if (formatString != null)
+            if (!string.IsNullOrEmpty(formatString))
             {
-                result = WithFormatClause(result, formatString == ""
-                    ? null
-                    : (TInterpolationFormatClause?)generator.InterpolationFormatClause(Escape(interpolatedString, formatString)));
+                result = WithFormatClause(
+                    result,
+                    (TInterpolationFormatClause?)generator.InterpolationFormatClause(Escape(interpolatedString, formatString)));
             }
 
             return result;

src/Features/Core/Portable/SimplifyInterpolation/Helpers.cs

@@ -85,6 +85,8 @@ private static IOperation Unwrap(IOperation expression)
 
                 if (invocation.Arguments.Length == 0)
                 {
+                    // A call to `.ToString()` at the end of the interpolation.  This is unnecessary.
+                    // Just remove entirely.
                     unwrapped = invocation.Instance;
                     formatString = "";