Options for handler style settable via .editorconfig

src/NServiceBus.Core.Analyzer.Fixes/Handlers/AddConventionBasedHandleMethodFixer.cs

@@ -1,9 +1,11 @@
 namespace NServiceBus.Core.Analyzer.Fixes;
 
+using System;
 using System.Collections.Immutable;
 using System.Composition;
 using System.Threading;
 using System.Threading.Tasks;
+using Handlers;
 using Microsoft.CodeAnalysis;
 using Microsoft.CodeAnalysis.CodeActions;
 using Microsoft.CodeAnalysis.CodeFixes;
@@ -12,7 +14,6 @@ namespace NServiceBus.Core.Analyzer.Fixes;
 using Microsoft.CodeAnalysis.Editing;
 using Microsoft.CodeAnalysis.Formatting;
 using Microsoft.CodeAnalysis.Simplification;
-using NServiceBus.Core.Analyzer.Handlers;
 
 [Shared]
 [ExportCodeFixProvider(LanguageNames.CSharp, Name = nameof(AddConventionBasedHandleMethodFixer))]
@@ -25,14 +26,19 @@ public class AddConventionBasedHandleMethodFixer : CodeFixProvider
     public override async Task RegisterCodeFixesAsync(CodeFixContext context)
     {
         var root = await context.Document.GetSyntaxRootAsync(context.CancellationToken).ConfigureAwait(false);
+        if (root is null)
+        {
+            return;
+        }
 
-        foreach (var diagnostic in context.Diagnostics)
+        if (EditorConfigSettings.KeyMatches(context.Document.Project.AnalyzerOptions, root.SyntaxTree, EditorConfigSettings.HandlerStyleKey, EditorConfigSettings.HandlerStyleInterfaces))
         {
-            if (root?.FindNode(diagnostic.Location.SourceSpan, getInnermostNodeForTie: true) is not { } node)
-            {
-                continue;
-            }
+            return;
+        }
 
+        foreach (var diagnostic in context.Diagnostics)
+        {
+            var node = root.FindNode(diagnostic.Location.SourceSpan, getInnermostNodeForTie: true);
             var classDecl = node.FirstAncestorOrSelf<ClassDeclarationSyntax>();
             if (classDecl is null || !HandlerFixerGuards.IsEmptyHandlerShell(classDecl))
             {

src/NServiceBus.Core.Analyzer.Fixes/Handlers/AddIHandleMessagesInterfaceFixer.cs

@@ -1,5 +1,6 @@
 namespace NServiceBus.Core.Analyzer.Fixes;
 
+using System;
 using System.Collections.Immutable;
 using System.Composition;
 using System.Threading;
@@ -25,14 +26,19 @@ public class AddIHandleMessagesInterfaceFixer : CodeFixProvider
     public override async Task RegisterCodeFixesAsync(CodeFixContext context)
     {
         var root = await context.Document.GetSyntaxRootAsync(context.CancellationToken).ConfigureAwait(false);
+        if (root is null)
+        {
+            return;
+        }
 
-        foreach (var diagnostic in context.Diagnostics)
+        if (EditorConfigSettings.KeyMatches(context.Document.Project.AnalyzerOptions, root.SyntaxTree, EditorConfigSettings.HandlerStyleKey, EditorConfigSettings.HandlerStyleConventions))
         {
-            if (root?.FindNode(diagnostic.Location.SourceSpan, getInnermostNodeForTie: true) is not { } node)
-            {
-                continue;
-            }
+            return;
+        }
 
+        foreach (var diagnostic in context.Diagnostics)
+        {
+            var node = root.FindNode(diagnostic.Location.SourceSpan, getInnermostNodeForTie: true);
             var classDecl = node.FirstAncestorOrSelf<ClassDeclarationSyntax>();
             if (classDecl is null || !HandlerFixerGuards.IsEmptyHandlerShell(classDecl))
             {

src/NServiceBus.Core.Analyzer.Fixes/NServiceBus.Core.Analyzer.Fixes.csproj

@@ -20,6 +20,7 @@
 
   <ItemGroup>
     <Compile Include="..\NServiceBus.Core.Analyzer\DiagnosticIds.cs" />
+    <Compile Include="..\NServiceBus.Core.Analyzer\EditorConfigSettings.cs" />
     <Compile Include="..\NServiceBus.Core.Analyzer\Features\FeatureKnownTypes.cs" LinkBase="Features" />
     <Compile Include="..\NServiceBus.Core.Analyzer\TypeSymbolExtensions.cs" />
     <Compile Include="..\NServiceBus.Core.Analyzer\NamespaceSymbolExtensions.cs" />

src/NServiceBus.Core.Analyzer/EditorConfigSettings.cs

@@ -0,0 +1,36 @@
+#nullable enable
+
+namespace NServiceBus.Core.Analyzer;
+
+using System;
+using System.Diagnostics.CodeAnalysis;
+using Microsoft.CodeAnalysis;
+using Microsoft.CodeAnalysis.Diagnostics;
+
+static class EditorConfigSettings
+{
+    /// <summary>
+    /// Get an editorconfig setting in an Analyzer. The AnalyzerOptions should be accessible from an Analyzer through <c>context.Options</c>
+    /// or in a CodeFixProvider from <c>context.Document.Project.AnalyzerOptions</c>.
+    /// </summary>
+    /// <returns></returns>
+    public static bool TryGetValue(AnalyzerOptions analyzerOptions, SyntaxTree? syntaxTree, string settingName, [NotNullWhen(true)] out string? value)
+    {
+        var provider = analyzerOptions.AnalyzerConfigOptionsProvider;
+
+        if (syntaxTree is null)
+        {
+            return provider.GlobalOptions.TryGetValue(settingName, out value);
+        }
+
+        var options = analyzerOptions.AnalyzerConfigOptionsProvider.GetOptions(syntaxTree);
+        return options.TryGetValue(settingName, out value);
+    }
+
+    public static bool KeyMatches(AnalyzerOptions analyzerOptions, SyntaxTree? syntaxTree, string settingName, string matchValue, StringComparison comparison = StringComparison.OrdinalIgnoreCase)
+        => TryGetValue(analyzerOptions, syntaxTree, settingName, out var value) && string.Equals(value, matchValue, comparison);
+
+    public const string HandlerStyleKey = "nservicebus_handler_style";
+    public const string HandlerStyleInterfaces = "interfaces";
+    public const string HandlerStyleConventions = "conventions";
+}