Implemented fix

Author: vweijsters

StyleCop.Analyzers/StyleCop.Analyzers.Test/OrderingRules/UsingCodeFixProviderUnitTests.cs

@@ -441,6 +441,42 @@ namespace TestNamespace2
             Assert.Empty(offeredFixes);
         }
 
+        /// <summary>
+        /// Verifies that the code fix will handle using statements in the else part of a #if directive trivia.
+        /// This is a regression test for #1528
+        /// </summary>
+        /// <returns>A <see cref="Task"/> representing the asynchronous unit test.</returns>
+        [Fact]
+        public async Task VerifyCodefixForElsePartOfDirectiveTriviaAsync()
+        {
+            var testCode = @"namespace NamespaceName
+{
+#if false
+    using System.Runtime.CompilerServices;
+#else
+    using System.Collections.Generic;
+    using System.Collections.Concurrent;
+#endif
+}
+";
+
+            var fixedTestCode = @"namespace NamespaceName
+{
+#if false
+    using System.Runtime.CompilerServices;
+#else
+    using System.Collections.Concurrent;
+    using System.Collections.Generic;
+#endif
+}
+";
+            var expected = this.CSharpDiagnostic(SA1210UsingDirectivesMustBeOrderedAlphabeticallyByNamespace.DiagnosticId).WithLocation(6, 5);
+
+            await this.VerifyCSharpDiagnosticAsync(testCode, expected, CancellationToken.None).ConfigureAwait(false);
+            await this.VerifyCSharpDiagnosticAsync(fixedTestCode, EmptyDiagnosticResults, CancellationToken.None).ConfigureAwait(false);
+            await this.VerifyCSharpFixAsync(testCode, fixedTestCode).ConfigureAwait(false);
+        }
+
         /// <inheritdoc/>
         protected override IEnumerable<string> GetDisabledDiagnostics()
         {

StyleCop.Analyzers/StyleCop.Analyzers/OrderingRules/UsingCodeFixProvider.cs

@@ -53,7 +53,7 @@ public override async Task RegisterCodeFixesAsync(CodeFixContext context)
             var syntaxRoot = await context.Document.GetSyntaxRootAsync(context.CancellationToken).ConfigureAwait(false);
             var compilationUnit = (CompilationUnitSyntax)syntaxRoot;
 
-            foreach (Diagnostic diagnostic in context.Diagnostics.Where(d => FixableDiagnostics.Contains(d.Id)))
+            foreach (Diagnostic diagnostic in context.Diagnostics)
             {
                 // do not offer a code fix for SA1200 when there are multiple namespaces in the source file
                 if ((diagnostic.Id == SA1200UsingDirectivesMustBePlacedWithinNamespace.DiagnosticId)
@@ -525,20 +525,50 @@ private static List<UsingDirectiveSyntax> GenerateUsings(List<UsingDirectiveSynt
                 {
                     var currentUsing = usingsList[i];
 
-                    triviaToMove.AddRange(currentUsing.GetLeadingTrivia().Where(tr => tr.IsDirective));
+                    triviaToMove.AddRange(currentUsing.GetLeadingTrivia().Where(tr => tr.IsDirective || tr.IsKind(SyntaxKind.DisabledTextTrivia)));
 
                     // preserve leading trivia (excluding directive trivia), indenting each line as appropriate
                     var newLeadingTrivia = currentUsing
                         .GetLeadingTrivia()
-                        .WithoutLeadingWhitespace()
-                        .Where(tr => !tr.IsDirective)
+                        .Where(tr => !tr.IsDirective && !tr.IsKind(SyntaxKind.DisabledTextTrivia))
                         .ToList();
 
                     if (i == 0)
                     {
                         newLeadingTrivia = StripFileHeader(newLeadingTrivia);
                     }
 
+                    // strip any leading whitespace on each line (and also all blank lines)
+                    var k = 0;
+                    var startOfLine = true;
+                    while (k < newLeadingTrivia.Count)
+                    {
+                        switch (newLeadingTrivia[k].Kind())
+                        {
+                            case SyntaxKind.WhitespaceTrivia:
+                                newLeadingTrivia.RemoveAt(k);
+                                break;
+
+                            case SyntaxKind.EndOfLineTrivia:
+                                if (startOfLine)
+                                {
+                                    newLeadingTrivia.RemoveAt(k);
+                                }
+                                else
+                                {
+                                    startOfLine = true;
+                                    k++;
+                                }
+
+                                break;
+
+                            default:
+                                startOfLine = newLeadingTrivia[k].IsDirective;
+                                k++;
+                                break;
+                        }
+                    }
+
                     for (var j = newLeadingTrivia.Count - 1; j >= 0; j--)
                     {
                         if (newLeadingTrivia[j].IsKind(SyntaxKind.EndOfLineTrivia))