Add Analyzer to prevent empty ArraySegment collection expression

see 83d04b0

Author: YoshiRulz

Directory.Packages.props

@@ -12,8 +12,8 @@
 		<PackageVersion Include="Meziantou.Polyfill" Version="1.0.50" />
 		<PackageVersion Include="Microsoft.Bcl.HashCode" Version="6.0.0" />
 		<PackageVersion Include="Microsoft.CodeAnalysis.BannedApiAnalyzers" Version="3.3.4" />
-		<PackageVersion Include="Microsoft.CodeAnalysis.CSharp" Version="4.8.0" />
-		<PackageVersion Include="Microsoft.CodeAnalysis.CSharp.Workspaces" Version="4.8.0" />
+		<PackageVersion Include="Microsoft.CodeAnalysis.CSharp" Version="4.14.0" />
+		<PackageVersion Include="Microsoft.CodeAnalysis.CSharp.Workspaces" Version="4.14.0" />
 		<PackageVersion Include="Microsoft.CodeAnalysis.CSharp.Analyzer.Testing" Version="1.1.2" />
 		<PackageVersion Include="Microsoft.CSharp" Version="4.7.0" />
 		<PackageVersion Include="Microsoft.Data.Sqlite.Core" Version="8.0.4" />
@@ -34,7 +34,7 @@
 		<PackageVersion Include="Silk.NET.WGL.Extensions.NV" Version="2.21.0" />
 		<PackageVersion Include="SQLitePCLRaw.provider.e_sqlite3" Version="2.1.8" />
 		<PackageVersion Include="StyleCop.Analyzers" Version="1.2.0-beta.556" /><!-- don't forget to update .stylecop.json at the same time -->
-		<PackageVersion Include="System.Collections.Immutable" Version="8.0.0" />
+		<PackageVersion Include="System.Collections.Immutable" Version="9.0.0" />
 		<PackageVersion Include="System.CommandLine" Version="2.0.0-beta4.22272.1" />
 		<PackageVersion Include="System.ComponentModel.Annotations" Version="5.0.0" />
 		<PackageVersion Include="System.Drawing.Common" Version="6.0.0" />

ExternalProjects/BizHawk.Analyzer/BrokenCollectionExpressionAnalyzer.cs

@@ -0,0 +1,35 @@
+namespace BizHawk.Analyzers;
+
+using System.Collections.Immutable;
+
+[DiagnosticAnalyzer(LanguageNames.CSharp)]
+public sealed class BrokenCollectionExpressionAnalyzer : DiagnosticAnalyzer
+{
+	private static readonly DiagnosticDescriptor DiagBrokenCollectionExpression = new(
+		id: "BHI1234",
+		title: "don't this",
+		messageFormat: "don't this",
+		category: "Usage",
+		defaultSeverity: DiagnosticSeverity.Warning,
+		isEnabledByDefault: true);
+
+	public override ImmutableArray<DiagnosticDescriptor> SupportedDiagnostics { get; }
+		= ImmutableArray.Create(/*HawkSourceAnalyzer.DiagWTF,*/ DiagBrokenCollectionExpression);
+
+	public override void Initialize(AnalysisContext context)
+	{
+		context.ConfigureGeneratedCodeAnalysis(GeneratedCodeAnalysisFlags.None);
+		context.EnableConcurrentExecution();
+		context.RegisterCompilationStartAction(initContext =>
+		{
+			var arraySegmentSym = initContext.Compilation.GetTypeByMetadataName("System.ArraySegment`1")!;
+			initContext.RegisterOperationAction(
+				oac =>
+				{
+					var operation = (ICollectionExpressionOperation) oac.Operation;
+					if (arraySegmentSym.Matches(operation.Type.OriginalDefinition)) DiagBrokenCollectionExpression.ReportAt(operation, oac);
+				},
+				OperationKind.CollectionExpression);
+		});
+	}
+}