Implemented SA1134 (incl. tests + code fix)

Author: vweijsters

StyleCop.Analyzers/StyleCop.Analyzers.CodeFixes/ReadabilityRules/SA1134CodeFixProvider.cs

@@ -0,0 +1,93 @@
+// Copyright (c) Tunnel Vision Laboratories, LLC. All Rights Reserved.
+// Licensed under the Apache License, Version 2.0. See LICENSE in the project root for license information.
+
+namespace StyleCop.Analyzers.ReadabilityRules
+{
+    using System.Collections.Generic;
+    using System.Collections.Immutable;
+    using System.Composition;
+    using System.Threading;
+    using System.Threading.Tasks;
+    using Helpers;
+    using Microsoft.CodeAnalysis;
+    using Microsoft.CodeAnalysis.CodeActions;
+    using Microsoft.CodeAnalysis.CodeFixes;
+    using Microsoft.CodeAnalysis.CSharp;
+    using Microsoft.CodeAnalysis.CSharp.Syntax;
+
+    /// <summary>
+    /// Implements a code fix for <see cref="SA1134AttributesMustNotShareLine"/>.
+    /// </summary>
+    [ExportCodeFixProvider(LanguageNames.CSharp, Name = nameof(SA1134CodeFixProvider))]
+    [Shared]
+    internal class SA1134CodeFixProvider : CodeFixProvider
+    {
+        /// <inheritdoc/>
+        public override ImmutableArray<string> FixableDiagnosticIds { get; } =
+            ImmutableArray.Create(SA1134AttributesMustNotShareLine.DiagnosticId);
+
+        /// <inheritdoc/>
+        public override FixAllProvider GetFixAllProvider()
+        {
+            return CustomFixAllProviders.BatchFixer;
+        }
+
+        /// <inheritdoc/>
+        public override Task RegisterCodeFixesAsync(CodeFixContext context)
+        {
+            foreach (var diagnostic in context.Diagnostics)
+            {
+                context.RegisterCodeFix(
+                    CodeAction.Create(
+                        ReadabilityResources.SA1134CodeFix,
+                        cancellationToken => GetTransformedDocumentAsync(context.Document, diagnostic, cancellationToken),
+                        nameof(SA1134CodeFixProvider)),
+                    diagnostic);
+            }
+
+            return SpecializedTasks.CompletedTask;
+        }
+
+        private static async Task<Document> GetTransformedDocumentAsync(Document document, Diagnostic diagnostic, CancellationToken cancellationToken)
+        {
+            var syntaxRoot = await document.GetSyntaxRootAsync(cancellationToken).ConfigureAwait(false);
+            var indentationOptions = IndentationOptions.FromDocument(document);
+
+            var attributeListSyntax = (AttributeListSyntax)syntaxRoot.FindNode(diagnostic.Location.SourceSpan);
+
+            // use the containing type to determine the indentation level, anything else is less reliable.
+            var containingType = attributeListSyntax.Parent?.Parent;
+            var indentationSteps = (containingType != null) ? IndentationHelper.GetIndentationSteps(indentationOptions, containingType) + 1 : 0;
+            var indentationTrivia = IndentationHelper.GenerateWhitespaceTrivia(indentationOptions, indentationSteps);
+
+            var tokensToReplace = new Dictionary<SyntaxToken, SyntaxToken>();
+
+            if (diagnostic.Properties.ContainsKey(SA1134AttributesMustNotShareLine.FixWithNewLineBeforeKey))
+            {
+                var token = attributeListSyntax.OpenBracketToken;
+                var prevToken = token.GetPreviousToken();
+
+                tokensToReplace[prevToken] = prevToken.WithTrailingTrivia(prevToken.TrailingTrivia.WithoutTrailingWhitespace().Add(SyntaxFactory.CarriageReturnLineFeed));
+
+                var newLeadingTrivia = token.LeadingTrivia.Insert(0, indentationTrivia);
+                tokensToReplace[token] = token.WithLeadingTrivia(newLeadingTrivia);
+            }
+
+            if (diagnostic.Properties.ContainsKey(SA1134AttributesMustNotShareLine.FixWithNewLineAfterKey))
+            {
+                var token = attributeListSyntax.CloseBracketToken;
+                var nextToken = token.GetNextToken();
+
+                tokensToReplace[token] = token.WithTrailingTrivia(token.TrailingTrivia.WithoutTrailingWhitespace().Add(SyntaxFactory.CarriageReturnLineFeed));
+
+                var newLeadingTrivia = nextToken.LeadingTrivia.Insert(0, indentationTrivia);
+                tokensToReplace[nextToken] = nextToken.WithLeadingTrivia(newLeadingTrivia);
+            }
+
+            var newSyntaxRoot = syntaxRoot.ReplaceTokens(tokensToReplace.Keys, (original, rewritten) => tokensToReplace[original]);
+            var newDocument = document.WithSyntaxRoot(newSyntaxRoot.WithoutFormatting());
+
+            return newDocument;
+        }
+    }
+}

StyleCop.Analyzers/StyleCop.Analyzers.CodeFixes/StyleCop.Analyzers.CodeFixes.csproj

@@ -128,6 +128,7 @@
     <Compile Include="ReadabilityRules\SA1131CodeFixProvider.cs" />
     <Compile Include="ReadabilityRules\SA1132CodeFixProvider.cs" />
     <Compile Include="ReadabilityRules\SA1133CodeFixProvider.cs" />
+    <Compile Include="ReadabilityRules\SA1134CodeFixProvider.cs" />
     <Compile Include="ReadabilityRules\SX1101CodeFixProvider.cs" />
     <Compile Include="Settings\SettingsFileCodeFixProvider.cs" />
     <Compile Include="SpacingRules\SA1003CodeFixProvider.cs" />