Fix CA1801 false positive with positional records primary ctor

eng/Versions.props

@@ -2,7 +2,7 @@
   <PropertyGroup>
     <VersionPrefix>3.3.2</VersionPrefix>
     <PreReleaseVersionLabel>beta1</PreReleaseVersionLabel>
-    <NetAnalyzersVersionPrefix>5.0.1</NetAnalyzersVersionPrefix>
+    <NetAnalyzersVersionPrefix>6.0.0</NetAnalyzersVersionPrefix>
     <NetAnalyzersPreReleaseVersionLabel>preview1</NetAnalyzersPreReleaseVersionLabel>
     <AnalyzerUtilitiesVersionPrefix>$(VersionPrefix)</AnalyzerUtilitiesVersionPrefix>
     <!--

src/NetAnalyzers/CSharp/Microsoft.CodeQuality.Analyzers/Maintainability/CSharpReviewUnusedParametersAnalyzer.cs

@@ -0,0 +1,35 @@
+// 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 Microsoft.CodeAnalysis;
+using Microsoft.CodeAnalysis.CSharp;
+using Microsoft.CodeAnalysis.Diagnostics;
+using Microsoft.CodeQuality.Analyzers.Maintainability;
+
+namespace Microsoft.CodeQuality.CSharp.Analyzers.Maintainability
+{
+    /// <summary>
+    /// CA1801: Review unused parameters
+    /// </summary>
+    [DiagnosticAnalyzer(LanguageNames.CSharp)]
+    public sealed class CSharpReviewUnusedParametersAnalyzer : ReviewUnusedParametersAnalyzer
+    {
+        private const SyntaxKind RecordDeclaration = (SyntaxKind)9063;
+
+        protected override bool IsPositionalRecordPrimaryConstructor(IMethodSymbol methodSymbol)
+        {
+            if (methodSymbol.MethodKind != MethodKind.Constructor)
+            {
+                return false;
+            }
+
+            if (methodSymbol.DeclaringSyntaxReferences.Length == 0)
+            {
+                return false;
+            }
+
+            return methodSymbol.DeclaringSyntaxReferences[0]
+                .GetSyntax()
+                .IsKind(RecordDeclaration);
+        }
+    }
+}

src/NetAnalyzers/Core/Microsoft.CodeQuality.Analyzers/Maintainability/ReviewUnusedParameters.cs

@@ -15,8 +15,7 @@ namespace Microsoft.CodeQuality.Analyzers.Maintainability
     /// <summary>
     /// CA1801: Review unused parameters
     /// </summary>
-    [DiagnosticAnalyzer(LanguageNames.CSharp, LanguageNames.VisualBasic)]
-    public sealed class ReviewUnusedParametersAnalyzer : DiagnosticAnalyzer
+    public abstract class ReviewUnusedParametersAnalyzer : DiagnosticAnalyzer
     {
         internal const string RuleId = "CA1801";
 
@@ -34,9 +33,9 @@ public sealed class ReviewUnusedParametersAnalyzer : DiagnosticAnalyzer
                                                                              isPortedFxCopRule: true,
                                                                              isDataflowRule: false);
 
-        public override ImmutableArray<DiagnosticDescriptor> SupportedDiagnostics => ImmutableArray.Create(Rule);
+        public sealed override ImmutableArray<DiagnosticDescriptor> SupportedDiagnostics => ImmutableArray.Create(Rule);
 
-        public override void Initialize(AnalysisContext context)
+        public sealed override void Initialize(AnalysisContext context)
         {
             context.EnableConcurrentExecution();
 
@@ -163,7 +162,7 @@ private static void ReportUnusedParameters(
         }
 
 #pragma warning disable RS1012 // Start action has no registered actions.
-        private static bool ShouldAnalyzeMethod(
+        private bool ShouldAnalyzeMethod(
             IMethodSymbol method,
             OperationBlockStartAnalysisContext startOperationBlockContext,
             INamedTypeSymbol? eventsArgSymbol,
@@ -196,6 +195,12 @@ private static bool ShouldAnalyzeMethod(
                 return false;
             }
 
+            // Ignore primary constructor (body-less) of positional records.
+            if (IsPositionalRecordPrimaryConstructor(method))
+            {
+                return false;
+            }
+
             // Ignore serialization special methods
             if (method.IsSerializationConstructor(serializationInfoType, streamingContextType) ||
                 method.IsGetObjectData(serializationInfoType, streamingContextType))
@@ -241,5 +246,7 @@ private static bool ShouldAnalyzeMethod(
 
             return true;
         }
+
+        protected abstract bool IsPositionalRecordPrimaryConstructor(IMethodSymbol methodSymbol);
     }
 }

src/NetAnalyzers/UnitTests/Microsoft.CodeQuality.Analyzers/Maintainability/ReviewUnusedParametersTests.Fixer.cs

@@ -4,10 +4,10 @@
 using Microsoft.CodeAnalysis.Testing;
 using Xunit;
 using VerifyCS = Test.Utilities.CSharpCodeFixVerifier<
-    Microsoft.CodeQuality.Analyzers.Maintainability.ReviewUnusedParametersAnalyzer,
+    Microsoft.CodeQuality.CSharp.Analyzers.Maintainability.CSharpReviewUnusedParametersAnalyzer,
     Microsoft.CodeQuality.CSharp.Analyzers.Maintainability.CSharpReviewUnusedParametersFixer>;
 using VerifyVB = Test.Utilities.VisualBasicCodeFixVerifier<
-    Microsoft.CodeQuality.Analyzers.Maintainability.ReviewUnusedParametersAnalyzer,
+    Microsoft.CodeQuality.VisualBasic.Analyzers.Maintainability.BasicReviewUnusedParametersAnalyzer,
     Microsoft.CodeQuality.VisualBasic.Analyzers.Maintainability.BasicReviewUnusedParametersFixer>;
 
 namespace Microsoft.CodeQuality.Analyzers.Maintainability.UnitTests

src/NetAnalyzers/UnitTests/Microsoft.CodeQuality.Analyzers/Maintainability/ReviewUnusedParametersTests.cs

@@ -9,10 +9,10 @@
 using Test.Utilities;
 using Xunit;
 using VerifyCS = Test.Utilities.CSharpCodeFixVerifier<
-    Microsoft.CodeQuality.Analyzers.Maintainability.ReviewUnusedParametersAnalyzer,
+    Microsoft.CodeQuality.CSharp.Analyzers.Maintainability.CSharpReviewUnusedParametersAnalyzer,
     Microsoft.CodeQuality.CSharp.Analyzers.Maintainability.CSharpReviewUnusedParametersFixer>;
 using VerifyVB = Test.Utilities.VisualBasicCodeFixVerifier<
-    Microsoft.CodeQuality.Analyzers.Maintainability.ReviewUnusedParametersAnalyzer,
+    Microsoft.CodeQuality.VisualBasic.Analyzers.Maintainability.BasicReviewUnusedParametersAnalyzer,
     Microsoft.CodeQuality.VisualBasic.Analyzers.Maintainability.BasicReviewUnusedParametersFixer>;
 
 namespace Microsoft.CodeQuality.Analyzers.Maintainability.UnitTests
@@ -1197,6 +1197,20 @@ public async Task CA1801_TopLevelStatements_NoDiagnostic()
             }.RunAsync();
         }
 
+        [Fact, WorkItem(4462, "https://github.com/dotnet/roslyn-analyzers/issues/4462")]
+        public async Task CA1801_CSharp_ImplicitRecord()
+        {
+            await new VerifyCS.Test
+            {
+                LanguageVersion = CodeAnalysis.CSharp.LanguageVersion.CSharp9,
+                ReferenceAssemblies = ReferenceAssemblies.Net.Net50,
+                TestCode = @"
+public record Person(string Name, int Age = 0);
+
+public record Person2(string Name, int Age = 0) {}",
+            }.RunAsync();
+        }
+
         #endregion
 
         #region Unit tests for analyzer diagnostic(s)
@@ -1371,6 +1385,24 @@ public void InnerM(int [|y|])
 }");
         }
 
+        [Fact, WorkItem(4462, "https://github.com/dotnet/roslyn-analyzers/issues/4462")]
+        public async Task CA1801_CSharp_Record()
+        {
+            await new VerifyCS.Test
+            {
+                LanguageVersion = CodeAnalysis.CSharp.LanguageVersion.CSharp9,
+                ReferenceAssemblies = ReferenceAssemblies.Net.Net50,
+                TestCode = @"
+public record OtherPerson
+{
+    public string Name { get; init; }
+
+    public OtherPerson(string name, int [|age|] = 0)
+        => Name = name;
+}",
+            }.RunAsync();
+        }
+
         #endregion
 
         #region Helpers

src/NetAnalyzers/VisualBasic/Microsoft.CodeQuality.Analyzers/Maintainability/BasicReviewUnusedParametersAnalyzer.vb

@@ -0,0 +1,20 @@
+' Copyright (c) Microsoft.  All Rights Reserved.  Licensed under the Apache License, Version 2.0.  See License.txt in the project root for license information.
+
+Imports Microsoft.CodeAnalysis
+Imports Microsoft.CodeAnalysis.Diagnostics
+Imports Microsoft.CodeQuality.Analyzers.Maintainability
+
+Namespace Microsoft.CodeQuality.VisualBasic.Analyzers.Maintainability
+
+    ''' <summary>
+    ''' CA1801: Review unused parameters
+    ''' </summary>
+    <DiagnosticAnalyzer(LanguageNames.VisualBasic)>
+    Public NotInheritable Class BasicReviewUnusedParametersAnalyzer
+        Inherits ReviewUnusedParametersAnalyzer
+
+        Protected Overrides Function IsPositionalRecordPrimaryConstructor(methodSymbol As IMethodSymbol) As Boolean
+            Return False
+        End Function
+    End Class
+End Namespace