Add invert conditional code.

src/Features/CSharp/Portable/InvertConditional/CSharpInvertConditionalCodeRefactoringProvider.cs

+// Copyright (c) Microsoft.  All Rights Reserved.  Licensed under the Apache License, Version 2.0.  See License.txt in the project root for license information.
+
+using System;
+using System.Composition;
+using System.Threading;
+using System.Threading.Tasks;
+using Microsoft.CodeAnalysis.CodeActions;
+using Microsoft.CodeAnalysis.CodeRefactorings;
+using Microsoft.CodeAnalysis.CSharp.Syntax;
+using Microsoft.CodeAnalysis.Editing;
+using Microsoft.CodeAnalysis.Shared.Extensions;
+
+namespace Microsoft.CodeAnalysis.CSharp.InvertConditional
+{
+    [ExportCodeRefactoringProvider(LanguageNames.CSharp), Shared]
+    internal class CSharpInvertConditionalCodeRefactoringProvider : CodeRefactoringProvider
+    {
+        public override async Task ComputeRefactoringsAsync(CodeRefactoringContext context)
+        {
+            var document = context.Document;
+            var span = context.Span;
+            var cancellationToken = context.CancellationToken;
+
+            if (span.Length > 0)
+            {
+                return;
+            }
+
+            var position = span.Start;
+            var conditional = await FindConditionalAsync(
+                document, position, cancellationToken).ConfigureAwait(false);
+            if (conditional == null)
+            {
+                return;
+            }
+
+            if (position < conditional.Span.Start || position > conditional.QuestionToken.Span.End)
+            {
+                return;
+            }
+
+            if (conditional.ColonToken.IsMissing)
+            {
+                return;
+            }
+
+            context.RegisterRefactoring(new MyCodeAction(
+                FeaturesResources.Invert_conditional,
+                c => InvertConditionalAsync(document, position, c)));
+        }
+
+        private static async Task<ConditionalExpressionSyntax> FindConditionalAsync(Document document, int position, CancellationToken cancellationToken)
+        {
+            var root = await document.GetSyntaxRootAsync(cancellationToken).ConfigureAwait(false);
+            var token = root.FindToken(position);
+
+            return token.Parent.FirstAncestorOrSelf<ConditionalExpressionSyntax>();
+        }
+
+        private async Task<Document> InvertConditionalAsync(
+            Document document, int position, CancellationToken cancellationToken)
+        {
+            var conditional = await FindConditionalAsync(
+                document, position, cancellationToken).ConfigureAwait(false);
+
+            var semanticModel = await document.GetSemanticModelAsync(cancellationToken).ConfigureAwait(false);
+            var root = await document.GetSyntaxRootAsync(cancellationToken).ConfigureAwait(false);
+
+            var editor = new SyntaxEditor(root, document.Project.Solution.Workspace);
+            var generator = editor.Generator;
+
+            var condition = conditional.Condition;
+            var whenTrue = conditional.WhenTrue;
+            var whenFalse = conditional.WhenFalse;
+            editor.ReplaceNode(
+                condition, generator.Negate(condition, semanticModel, cancellationToken));
+
+            editor.ReplaceNode(whenTrue, whenFalse.WithTriviaFrom(whenTrue));
+            editor.ReplaceNode(whenFalse, whenTrue.WithTriviaFrom(whenFalse));
+
+            return document.WithSyntaxRoot(editor.GetChangedRoot());
+        }
+
+        private class MyCodeAction : CodeAction.DocumentChangeAction
+        {
+            public MyCodeAction(string title, Func<CancellationToken, Task<Document>> createChangedDocument) 
+                : base(title, createChangedDocument)
+            {
+            }
+        }
+    }
+}

src/Features/Core/Portable/FeaturesResources.Designer.cs

@@ -2008,6 +2008,15 @@ internal class FeaturesResources {
             }
         }
         
+        /// <summary>
+        ///   Looks up a localized string similar to Invert conditional.
+        /// </summary>
+        internal static string Invert_conditional {
+            get {
+                return ResourceManager.GetString("Invert_conditional", resourceCulture);
+            }
+        }
+        
         /// <summary>
         ///   Looks up a localized string similar to is.
         /// </summary>

src/Features/Core/Portable/FeaturesResources.resx

@@ -1430,4 +1430,7 @@ This version used in: {2}</value>
   <data name="Type_0_has_a_private_member_1_that_can_be_removed_as_the_value_assigned_to_it_is_never_read" xml:space="preserve">
     <value>Type '{0}' has a private member '{1}' that can be removed as the value assigned to it is never read.</value>
   </data>
+  <data name="Invert_conditional" xml:space="preserve">
+    <value>Invert conditional</value>
+  </data>
 </root>
\ No newline at end of file

src/Features/Core/Portable/xlf/FeaturesResources.cs.xlf

@@ -67,6 +67,11 @@
         <target state="translated">Formátuje se dokument.</target>
         <note />
       </trans-unit>
+      <trans-unit id="Invert_conditional">
+        <source>Invert conditional</source>
+        <target state="new">Invert conditional</target>
+        <note />
+      </trans-unit>
       <trans-unit id="Related_method_signatures_found_in_metadata_will_not_be_updated">
         <source>Related method signatures found in metadata will not be updated.</source>
         <target state="translated">Podpisy souvisejících metod nalezené v metadatech se nebudou aktualizovat.</target>

src/Features/Core/Portable/xlf/FeaturesResources.de.xlf

@@ -67,6 +67,11 @@
         <target state="translated">Dokument wird formatiert</target>
         <note />
       </trans-unit>
+      <trans-unit id="Invert_conditional">
+        <source>Invert conditional</source>
+        <target state="new">Invert conditional</target>
+        <note />
+      </trans-unit>
       <trans-unit id="Related_method_signatures_found_in_metadata_will_not_be_updated">
         <source>Related method signatures found in metadata will not be updated.</source>
         <target state="translated">In Metadaten gefundene ähnliche Methodensignaturen werden nicht aktualisiert.</target>

src/Features/Core/Portable/xlf/FeaturesResources.es.xlf

@@ -67,6 +67,11 @@
         <target state="translated">Aplicando formato al documento</target>
         <note />
       </trans-unit>
+      <trans-unit id="Invert_conditional">
+        <source>Invert conditional</source>
+        <target state="new">Invert conditional</target>
+        <note />
+      </trans-unit>
       <trans-unit id="Related_method_signatures_found_in_metadata_will_not_be_updated">
         <source>Related method signatures found in metadata will not be updated.</source>
         <target state="translated">Las signaturas de método relacionadas encontradas en los metadatos no se actualizarán.</target>

src/Features/Core/Portable/xlf/FeaturesResources.fr.xlf

@@ -67,6 +67,11 @@
         <target state="translated">Mise en forme du document</target>
         <note />
       </trans-unit>
+      <trans-unit id="Invert_conditional">
+        <source>Invert conditional</source>
+        <target state="new">Invert conditional</target>
+        <note />
+      </trans-unit>
       <trans-unit id="Related_method_signatures_found_in_metadata_will_not_be_updated">
         <source>Related method signatures found in metadata will not be updated.</source>
         <target state="translated">Les signatures de méthode associées trouvées dans les métadonnées ne seront pas mises à jour.</target>

src/Features/Core/Portable/xlf/FeaturesResources.it.xlf

@@ -67,6 +67,11 @@
         <target state="translated">Formattazione del documento</target>
         <note />
       </trans-unit>
+      <trans-unit id="Invert_conditional">
+        <source>Invert conditional</source>
+        <target state="new">Invert conditional</target>
+        <note />
+      </trans-unit>
       <trans-unit id="Related_method_signatures_found_in_metadata_will_not_be_updated">
         <source>Related method signatures found in metadata will not be updated.</source>
         <target state="translated">Le firme del metodo correlate trovate nei metadati non verranno aggiornate.</target>

src/Features/Core/Portable/xlf/FeaturesResources.ja.xlf

@@ -67,6 +67,11 @@
         <target state="translated">ドキュメントの書式設定</target>
         <note />
       </trans-unit>
+      <trans-unit id="Invert_conditional">
+        <source>Invert conditional</source>
+        <target state="new">Invert conditional</target>
+        <note />
+      </trans-unit>
       <trans-unit id="Related_method_signatures_found_in_metadata_will_not_be_updated">
         <source>Related method signatures found in metadata will not be updated.</source>
         <target state="translated">メタデータ内に検出される関連するメソッド シグネチャは更新されません。</target>

src/Features/Core/Portable/xlf/FeaturesResources.ko.xlf

@@ -67,6 +67,11 @@
         <target state="translated">문서 서식 지정</target>
         <note />
       </trans-unit>
+      <trans-unit id="Invert_conditional">
+        <source>Invert conditional</source>
+        <target state="new">Invert conditional</target>
+        <note />
+      </trans-unit>
       <trans-unit id="Related_method_signatures_found_in_metadata_will_not_be_updated">
         <source>Related method signatures found in metadata will not be updated.</source>
         <target state="translated">메타데이터에서 찾은 관련 메서드 시그니처가 업데이트되지 않습니다.</target>

src/Features/Core/Portable/xlf/FeaturesResources.pl.xlf

@@ -67,6 +67,11 @@
         <target state="translated">Formatowanie dokumentu</target>
         <note />
       </trans-unit>
+      <trans-unit id="Invert_conditional">
+        <source>Invert conditional</source>
+        <target state="new">Invert conditional</target>
+        <note />
+      </trans-unit>
       <trans-unit id="Related_method_signatures_found_in_metadata_will_not_be_updated">
         <source>Related method signatures found in metadata will not be updated.</source>
         <target state="translated">Sygnatury powiązanych metod znalezione w metadanych nie zostaną zaktualizowane.</target>

src/Features/Core/Portable/xlf/FeaturesResources.pt-BR.xlf

@@ -67,6 +67,11 @@
         <target state="translated">Formatando documento</target>
         <note />
       </trans-unit>
+      <trans-unit id="Invert_conditional">
+        <source>Invert conditional</source>
+        <target state="new">Invert conditional</target>
+        <note />
+      </trans-unit>
       <trans-unit id="Related_method_signatures_found_in_metadata_will_not_be_updated">
         <source>Related method signatures found in metadata will not be updated.</source>
         <target state="translated">As assinaturas de método relacionadas encontradas nos metadados não serão atualizadas.</target>

src/Features/Core/Portable/xlf/FeaturesResources.ru.xlf

@@ -67,6 +67,11 @@
         <target state="translated">Форматирование документа</target>
         <note />
       </trans-unit>
+      <trans-unit id="Invert_conditional">
+        <source>Invert conditional</source>
+        <target state="new">Invert conditional</target>
+        <note />
+      </trans-unit>
       <trans-unit id="Related_method_signatures_found_in_metadata_will_not_be_updated">
         <source>Related method signatures found in metadata will not be updated.</source>
         <target state="translated">Связанные сигнатуры методов, найденные в метаданных, не будут обновлены.</target>

src/Features/Core/Portable/xlf/FeaturesResources.tr.xlf

@@ -67,6 +67,11 @@
         <target state="translated">Belge biçimlendiriliyor</target>
         <note />
       </trans-unit>
+      <trans-unit id="Invert_conditional">
+        <source>Invert conditional</source>
+        <target state="new">Invert conditional</target>
+        <note />
+      </trans-unit>
       <trans-unit id="Related_method_signatures_found_in_metadata_will_not_be_updated">
         <source>Related method signatures found in metadata will not be updated.</source>
         <target state="translated">Meta verilerde bulunan ilgili metot imzaları güncelleştirilmez.</target>

src/Features/Core/Portable/xlf/FeaturesResources.zh-Hans.xlf

@@ -67,6 +67,11 @@
         <target state="translated">设置文档格式</target>
         <note />
       </trans-unit>
+      <trans-unit id="Invert_conditional">
+        <source>Invert conditional</source>
+        <target state="new">Invert conditional</target>
+        <note />
+      </trans-unit>
       <trans-unit id="Related_method_signatures_found_in_metadata_will_not_be_updated">
         <source>Related method signatures found in metadata will not be updated.</source>
         <target state="translated">不更新在元数据中发现的相关方法签名。</target>

src/Features/Core/Portable/xlf/FeaturesResources.zh-Hant.xlf

@@ -67,6 +67,11 @@
         <target state="translated">正在將文件格式化</target>
         <note />
       </trans-unit>
+      <trans-unit id="Invert_conditional">
+        <source>Invert conditional</source>
+        <target state="new">Invert conditional</target>
+        <note />
+      </trans-unit>
       <trans-unit id="Related_method_signatures_found_in_metadata_will_not_be_updated">
         <source>Related method signatures found in metadata will not be updated.</source>
         <target state="translated">將不會更新中繼資料中所找到的相關方法簽章。</target>