Use GetNestedType.Match

Author: JohanLarsson

ReflectionAnalyzers/Helpers/Reflection/Filters/Types.cs

@@ -130,7 +130,7 @@ static bool ByNull(ISymbol? first, ISymbol? other, [NotNullWhen(true)] out ISymb
                 return false;
             }
 
-            static ImmutableArray<IParameterSymbol> Parameters(ISymbol symbol)
+            static ImmutableArray<IParameterSymbol> Parameters(ISymbol? symbol)
             {
                 return symbol switch
                 {

ReflectionAnalyzers/Helpers/Reflection/GetNestedType.cs

@@ -0,0 +1,58 @@
+namespace ReflectionAnalyzers;
+
+using System.Threading;
+using Gu.Roslyn.AnalyzerExtensions;
+using Microsoft.CodeAnalysis;
+using Microsoft.CodeAnalysis.CSharp.Syntax;
+
+internal readonly struct GetNestedType
+{
+    internal readonly InvocationExpressionSyntax Invocation;
+    internal readonly IMethodSymbol Target;
+    internal readonly ReflectedMember Member;
+    internal readonly Name Name;
+    internal readonly Flags Flags;
+
+    private GetNestedType(InvocationExpressionSyntax invocation, IMethodSymbol target, ReflectedMember member, Name name, Flags flags)
+    {
+        this.Invocation = invocation;
+        this.Target = target;
+        this.Member = member;
+        this.Name = name;
+        this.Flags = flags;
+    }
+
+    internal INamedTypeSymbol? Single => this.Member.Match == FilterMatch.Single ? (INamedTypeSymbol)this.Member.Symbol! : null;
+
+    /// <summary>
+    /// Check if <paramref name="candidate"/> is a call to Type.GetField.
+    /// </summary>
+    internal static GetNestedType? Match(ExpressionSyntax candidate, SemanticModel semanticModel, CancellationToken cancellationToken)
+    {
+        if (GetX.FindInvocation(candidate, semanticModel, cancellationToken) is { } invocation)
+        {
+            return Match(invocation, semanticModel, cancellationToken);
+        }
+
+        return null;
+    }
+
+    /// <summary>
+    /// Check if <paramref name="candidate"/> is a call to Type.GetField.
+    /// </summary>
+    internal static GetNestedType? Match(InvocationExpressionSyntax candidate, SemanticModel semanticModel, CancellationToken cancellationToken)
+    {
+        if (candidate.TryGetTarget(KnownSymbol.Type.GetNestedType, semanticModel, cancellationToken, out var target))
+        {
+            if (ReflectedMember.TryGetType(candidate, semanticModel, cancellationToken, out var type, out var typeSource) &&
+                Name.TryCreate(candidate, target, semanticModel, cancellationToken, out var name) &&
+                Flags.TryCreate(candidate, target, semanticModel, cancellationToken, out var flags) &&
+                ReflectedMember.TryCreate(target, candidate, type, typeSource, name, flags.Effective, Types.Any, semanticModel.Compilation, out var member))
+            {
+                return new GetNestedType(candidate, target, member, name, flags);
+            }
+        }
+
+        return null;
+    }
+}

ReflectionAnalyzers/Helpers/Reflection/GetX.cs

@@ -13,14 +13,6 @@
     /// </summary>
     internal static class GetX
     {
-        /// <summary>
-        /// Check if <paramref name="invocation"/> is a call to Type.GetNestedType.
-        /// </summary>
-        internal static bool TryMatchGetNestedType(InvocationExpressionSyntax invocation, SemanticModel semanticModel, CancellationToken cancellationToken, out ReflectedMember member, out Name name, out Flags flags)
-        {
-            return TryMatchGetX(invocation, KnownSymbol.Type.GetNestedType, semanticModel, cancellationToken, out member, out name, out flags);
-        }
-
         internal static InvocationExpressionSyntax? FindInvocation(ExpressionSyntax candidate, SemanticModel semanticModel, CancellationToken cancellationToken)
         {
             return candidate switch
@@ -40,36 +32,5 @@ when semanticModel.TryGetSymbol(identifierName, cancellationToken, out ILocalSym
                 _ => null,
             };
         }
-
-        /// <summary>
-        /// Handles GetField, GetEvent, GetMember, GetMethod...
-        /// </summary>
-        private static bool TryMatchGetX(InvocationExpressionSyntax invocation, QualifiedMethod getXMethod, SemanticModel semanticModel, CancellationToken cancellationToken, out ReflectedMember member, out Name name, out Flags flags)
-        {
-            if (invocation.TryGetTarget(getXMethod, semanticModel, cancellationToken, out var getX))
-            {
-                if (ReflectedMember.TryGetType(invocation, semanticModel, cancellationToken, out var type, out var typeSource) &&
-                    Name.TryCreate(invocation, getX, semanticModel, cancellationToken, out name) &&
-                    Flags.TryCreate(invocation, getX, semanticModel, cancellationToken, out flags) &&
-                    ReflectedMember.TryCreate(getX, invocation, type, typeSource, name, flags.Effective, Types.Any, semanticModel.Compilation, out member))
-                {
-                    return true;
-                }
-
-                if (getXMethod.Name != "GetNestedType" &&
-                    Flags.TryCreate(invocation, getX, semanticModel, cancellationToken, out flags) &&
-                    flags.AreInSufficient)
-                {
-                    _ = Name.TryCreate(invocation, getX, semanticModel, cancellationToken, out name);
-                    member = new ReflectedMember(type, typeSource, null, getX, invocation, FilterMatch.InSufficientFlags);
-                    return true;
-                }
-            }
-
-            member = default;
-            name = default;
-            flags = default;
-            return false;
-        }
     }
 }

ReflectionAnalyzers/Helpers/Reflection/Type.cs

@@ -227,10 +227,10 @@ when invocation.TryGetTarget(KnownSymbol.Type.GetGenericTypeDefinition, recursio
                     return true;
 
                 case InvocationExpressionSyntax invocation
-                    when GetX.TryMatchGetNestedType(invocation, recursion.SemanticModel, recursion.CancellationToken, out var reflectedMember, out _, out _):
+                    when GetNestedType.Match(invocation, recursion.SemanticModel, recursion.CancellationToken) is { Single: { } type }:
                     source = invocation;
-                    result = reflectedMember.Symbol as ITypeSymbol;
-                    return result != null && reflectedMember.Match == FilterMatch.Single;
+                    result = type;
+                    return true;
                 case InvocationExpressionSyntax { Expression: MemberAccessExpressionSyntax memberAccess } invocation
                     when invocation.TryGetTarget(KnownSymbol.Type.MakeGenericType, recursion.SemanticModel, recursion.CancellationToken, out _) &&
                          TypeArguments.Find(invocation, recursion.SemanticModel, recursion.CancellationToken) is { } typeArguments &&

ReflectionAnalyzers/NodeAnalzers/GetXAnalyzer.cs

@@ -301,8 +301,14 @@ private static bool TryGetX(SyntaxNodeAnalysisContext context, out ReflectedMemb
                     return true;
                 }
 
-                types = default;
-                return GetX.TryMatchGetNestedType(candidate, context.SemanticModel, context.CancellationToken, out member, out name, out flags);
+                if (GetNestedType.Match(candidate, context.SemanticModel, context.CancellationToken) is { } getNestedType)
+                {
+                    member = getNestedType.Member;
+                    name = getNestedType.Name;
+                    flags = getNestedType.Flags;
+                    types = default;
+                    return true;
+                }
             }
 
             member = default;