Merge pull request #1198 from KevinH-MS/master

Minor refactorings:

src/ExpressionEvaluator/CSharp/Test/ExpressionCompiler/ExpressionCompilerTests.cs

@@ -3774,7 +3774,7 @@ static void M()
                 }
             }
 
-            var references = ImmutableArray.Create<MetadataReference>(
+            var references = ImmutableArray.Create(
                     MscorlibRef,
                     referenceD0,
                     referenceN0, // From D0
@@ -3790,11 +3790,11 @@ static void M()
             // Expression references ambiguous modules.
             string error;
             context.CompileExpression("x.F0 + y.F0", out error);
-            Assert.Equal(error, "error CS7079: The type 'A0' is defined in a module that has not been added. You must add the module '" + assemblyName + "_N0.netmodule'.");
+            Assert.Equal("error CS7079: The type 'A0' is defined in a module that has not been added. You must add the module '" + assemblyName + "_N0.netmodule'.", error);
             context.CompileExpression("y.F0", out error);
-            Assert.Equal(error, "error CS7079: The type 'A0' is defined in a module that has not been added. You must add the module '" + assemblyName + "_N0.netmodule'.");
+            Assert.Equal("error CS7079: The type 'A0' is defined in a module that has not been added. You must add the module '" + assemblyName + "_N0.netmodule'.", error);
             context.CompileExpression("z.F1", out error);
-            Assert.Equal(error, "error CS7079: The type 'A1' is defined in a module that has not been added. You must add the module '" + assemblyName + "_N0.netmodule'.");
+            Assert.Equal("error CS7079: The type 'A1' is defined in a module that has not been added. You must add the module '" + assemblyName + "_N0.netmodule'.", error);
 
             // Expression does not reference ambiguous modules.
             var testData = new CompilationTestData();

src/ExpressionEvaluator/Core/Source/ExpressionCompiler/MetadataUtilities.cs

@@ -159,9 +159,10 @@ private static PortableExecutableReference MakeAssemblyMetadata(ModuleMetadata m
         internal static string GetFileNameWithoutExtension(string fileName)
         {
             var lastDotIndex = fileName.LastIndexOf('.');
-            if ((lastDotIndex > 0) && (lastDotIndex + 1 < fileName.Length))
+            var extensionStartIndex = lastDotIndex + 1;
+            if ((lastDotIndex > 0) && (extensionStartIndex < fileName.Length))
             {
-                var extension = fileName.Substring(lastDotIndex + 1);
+                var extension = fileName.Substring(extensionStartIndex);
                 switch (extension)
                 {
                     case "dll":