[release/10.0.2xx] Fix CA1869 false positive in top-level statements (#51483)

Author: eiriktsarpalis

src/Microsoft.CodeAnalysis.NetAnalyzers/src/Microsoft.CodeAnalysis.NetAnalyzers/Microsoft.NetCore.Analyzers/Performance/AvoidSingleUseOfLocalJsonSerializerOptions.cs

@@ -1,15 +1,15 @@
 // Copyright (c) Microsoft.  All Rights Reserved.  Licensed under the MIT license.  See License.txt in the project root for license information.
 
-using Microsoft.CodeAnalysis.Diagnostics;
-using Microsoft.CodeAnalysis;
+using System;
+using System.Collections.Generic;
 using System.Collections.Immutable;
+using System.Diagnostics;
+using System.Diagnostics.CodeAnalysis;
 using Analyzer.Utilities;
 using Analyzer.Utilities.Extensions;
+using Microsoft.CodeAnalysis;
+using Microsoft.CodeAnalysis.Diagnostics;
 using Microsoft.CodeAnalysis.Operations;
-using System.Diagnostics.CodeAnalysis;
-using System;
-using System.Collections.Generic;
-using System.Diagnostics;
 
 namespace Microsoft.NetCore.Analyzers.Performance
 {
@@ -60,6 +60,12 @@ private static void OnCompilationStart(CompilationStartAnalysisContext context)
                     INamedTypeSymbol? typeSymbol = operation.Constructor?.ContainingType;
                     if (SymbolEqualityComparer.Default.Equals(typeSymbol, jsonSerializerOptionsSymbol))
                     {
+                        // Don't report diagnostic for top-level statements as caching there is less impactful
+                        if (context.ContainingSymbol is IMethodSymbol method && method.IsTopLevelStatementsEntryPointMethod())
+                        {
+                            return;
+                        }
+
                         if (IsCtorUsedAsArgumentForJsonSerializer(operation, jsonSerializerSymbol) ||
                             IsLocalUsedAsArgumentForJsonSerializerOnly(operation, jsonSerializerSymbol, jsonSerializerOptionsSymbol))
                         {

src/Microsoft.CodeAnalysis.NetAnalyzers/src/RulesMissingDocumentation.md

@@ -2,3 +2,7 @@
 
 Rule ID | Missing Help Link | Title |
 --------|-------------------|-------|
+CA1873 | <https://learn.microsoft.com/dotnet/fundamentals/code-analysis/quality-rules/ca1873> | Avoid potentially expensive logging |
+CA1874 | <https://learn.microsoft.com/dotnet/fundamentals/code-analysis/quality-rules/ca1874> | Use 'Regex.IsMatch' |
+CA1875 | <https://learn.microsoft.com/dotnet/fundamentals/code-analysis/quality-rules/ca1875> | Use 'Regex.Count' |
+CA2023 | <https://learn.microsoft.com/dotnet/fundamentals/code-analysis/quality-rules/ca2023> | Invalid braces in message template |

src/Microsoft.CodeAnalysis.NetAnalyzers/tests/Microsoft.CodeAnalysis.NetAnalyzers.UnitTests/Microsoft.NetCore.Analyzers/Performance/AvoidSingleUseOfLocalJsonSerializerOptionsTests.cs

@@ -3,6 +3,7 @@
 using System.Collections.Generic;
 using System.Linq;
 using System.Threading.Tasks;
+using Microsoft.CodeAnalysis;
 using Microsoft.CodeAnalysis.CSharp;
 using Xunit;
 using VerifyCS = Test.Utilities.CSharpCodeFixVerifier<
@@ -820,6 +821,81 @@ Shared Function Serialize(Of T)(values As T()) As String
                     End Function
                 End Class
                 """);
+
+        [Fact]
+        public Task CS_TopLevelStatements_UseNewOptionsAsArgument_NoWarn()
+        {
+            var test = new VerifyCS.Test
+            {
+                TestState =
+                {
+                    OutputKind = OutputKind.ConsoleApplication,
+                    Sources =
+                    {
+                        """
+                        using System.Text.Json;
+
+                        string json = JsonSerializer.Serialize(new[] { 1, 2, 3 }, new JsonSerializerOptions { AllowTrailingCommas = true });
+                        """
+                    }
+                },
+                LanguageVersion = CodeAnalysis.CSharp.LanguageVersion.CSharp9
+            };
+            return test.RunAsync();
+        }
+
+        [Fact]
+        public Task CS_TopLevelStatements_UseNewLocalOptionsAsArgument_NoWarn()
+        {
+            var test = new VerifyCS.Test
+            {
+                TestState =
+                {
+                    OutputKind = OutputKind.ConsoleApplication,
+                    Sources =
+                    {
+                        """
+                        using System.Text.Json;
+
+                        JsonSerializerOptions options = new()
+                        {
+                            PropertyNameCaseInsensitive = true,
+                            ReadCommentHandling = JsonCommentHandling.Skip
+                        };
+
+                        var output = JsonSerializer.Deserialize<int[]>("[1,2,3]", options);
+                        """
+                    }
+                },
+                LanguageVersion = CodeAnalysis.CSharp.LanguageVersion.CSharp9
+            };
+            return test.RunAsync();
+        }
+
+        [Fact]
+        public Task CS_TopLevelStatements_UseNewLocalOptionsAsArgument_Assignment_NoWarn()
+        {
+            var test = new VerifyCS.Test
+            {
+                TestState =
+                {
+                    OutputKind = OutputKind.ConsoleApplication,
+                    Sources =
+                    {
+                        """
+                        using System.Text.Json;
+
+                        JsonSerializerOptions options;
+                        options = new JsonSerializerOptions();
+
+                        var output = JsonSerializer.Deserialize<int[]>("[1,2,3]", options);
+                        """
+                    }
+                },
+                LanguageVersion = CodeAnalysis.CSharp.LanguageVersion.CSharp9
+            };
+            return test.RunAsync();
+        }
         #endregion
     }
 }