Check for LimitProcessingConcurrencyTo

Author: mikeminutillo

src/NServiceBus.AzureFunctions.Analyzer.Tests/AzureFunctionsConfigurationAnalyzerTests.cs

@@ -6,23 +6,47 @@ namespace NServiceBus.AzureFunctions.Analyzer.Tests
     [TestFixture]
     public class AzureFunctionsConfigurationAnalyzerTests : AnalyzerTestFixture<AzureFunctionsConfigurationAnalyzer>
     {
-        // IEndpointInstance
-        [TestCase("ServiceBusTriggeredEndpointConfiguration", "obj.AdvancedConfiguration.PurgeOnStartup(true)")]
-        public Task DiagnosticIsReportedForCorePublicMethods(string type, string call)
+        [Test]
+        public Task DiagnosticIsReportedForPurgeOnStartup()
         {
             var source =
                 $@"using NServiceBus; 
 using System;
 using System.Threading.Tasks; 
 class Foo
 {{
-    void Bar({type} obj)
+    void Bar(ServiceBusTriggeredEndpointConfiguration endpointConfig)
     {{
-        [|{call}|];
+        [|endpointConfig.AdvancedConfiguration.PurgeOnStartup(true)|];
+
+        var advancedConfig = endpointConfig.AdvancedConfiguration;
+        [|advancedConfig.PurgeOnStartup(true)|];
     }}
 }}";
 
             return Assert(AzureFunctionsDiagnostics.PurgeOnStartupNotAllowedId, source);
         }
+
+        [Test]
+        public Task DiagnosticIsReportedForLimitMessageProcessingConcurrencyTo()
+        {
+            var source =
+                $@"using NServiceBus; 
+using System;
+using System.Threading.Tasks; 
+class Foo
+{{
+    void Bar(ServiceBusTriggeredEndpointConfiguration endpointConfig)
+    {{
+        [|endpointConfig.AdvancedConfiguration.LimitMessageProcessingConcurrencyTo(5)|];
+
+        var advancedConfig = endpointConfig.AdvancedConfiguration;
+        [|advancedConfig.LimitMessageProcessingConcurrencyTo(5)|];
+    }}
+}}";
+
+            return Assert(AzureFunctionsDiagnostics.LimitMessageProcessingToNotAllowedId, source);
+        }
+
     }
 }

src/NServiceBus.AzureFunctions.Analyzer/AzureFunctionsConfigurationAnalyzer.cs

@@ -1,5 +1,6 @@
 namespace NServiceBus.AzureFunctions.Analyzer
 {
+    using System.Collections.Generic;
     using System.Collections.Immutable;
     using Microsoft.CodeAnalysis;
     using Microsoft.CodeAnalysis.CSharp;
@@ -11,7 +12,8 @@ namespace NServiceBus.AzureFunctions.Analyzer
     public class AzureFunctionsConfigurationAnalyzer : DiagnosticAnalyzer
     {
         public override ImmutableArray<DiagnosticDescriptor> SupportedDiagnostics { get; } = ImmutableArray.Create(
-            AzureFunctionsDiagnostics.PurgeOnStartupNotAllowed
+            AzureFunctionsDiagnostics.PurgeOnStartupNotAllowed,
+            AzureFunctionsDiagnostics.LimitMessageProcessingToNotAllowed
         );
 
         public override void Initialize(AnalysisContext context)
@@ -33,7 +35,7 @@ static void Analyze(SyntaxNodeAnalysisContext context)
                 return;
             }
 
-            if (memberAccessExpression.Name.Identifier.Text != "PurgeOnStartup")
+            if (!NotAllowedEndpointConfigurationMethods.TryGetValue(memberAccessExpression.Name.Identifier.Text, out var diagnosticDescriptor))
             {
                 return;
             }
@@ -47,8 +49,15 @@ static void Analyze(SyntaxNodeAnalysisContext context)
 
             if (methodSymbol.ReceiverType.ToString() == "NServiceBus.EndpointConfiguration")
             {
-                context.ReportDiagnostic(AzureFunctionsDiagnostics.PurgeOnStartupNotAllowed, invocationExpression);
+                context.ReportDiagnostic(diagnosticDescriptor, invocationExpression);
             }
         }
+
+        static readonly Dictionary<string, DiagnosticDescriptor> NotAllowedEndpointConfigurationMethods
+            = new Dictionary<string, DiagnosticDescriptor>
+            {
+                ["PurgeOnStartup"] = AzureFunctionsDiagnostics.PurgeOnStartupNotAllowed,
+                ["LimitMessageProcessingConcurrencyTo"] = AzureFunctionsDiagnostics.LimitMessageProcessingToNotAllowed
+            };
     }
 }

src/NServiceBus.AzureFunctions.Analyzer/AzureFunctionsDiagnostics.cs

@@ -5,6 +5,7 @@
     public static class AzureFunctionsDiagnostics
     {
         public const string PurgeOnStartupNotAllowedId = "NSBAF0001";
+        public const string LimitMessageProcessingToNotAllowedId = "NSBAF0002";
 
         const string DiagnosticCategory = "NServiceBus.AzureFunctions";
 
@@ -16,5 +17,15 @@ public static class AzureFunctionsDiagnostics
              defaultSeverity: DiagnosticSeverity.Error,
              isEnabledByDefault: true
             );
+
+        internal static readonly DiagnosticDescriptor LimitMessageProcessingToNotAllowed = new DiagnosticDescriptor(
+             id: LimitMessageProcessingToNotAllowedId,
+             title: "LimitMessageProcessing is not supported in Azure Functions",
+             messageFormat: "Azure Functions endpoints do not control the message receiver and cannot limit message processing concurrency.",
+             category: DiagnosticCategory,
+             defaultSeverity: DiagnosticSeverity.Error,
+             isEnabledByDefault: true
+            );
+
     }
 }