Use type symbols for lookup in new analyzers

Author: Sergio0694

src/CommunityToolkit.Mvvm.SourceGenerators/Diagnostics/Analyzers/InvalidClassLevelNotifyDataErrorInfoAttributeAnalyzer.cs

@@ -35,13 +35,15 @@ public override void Initialize(AnalysisContext context)
             }
 
             // Only inspect classes that are using [NotifyDataErrorInfo]
-            if (!classSymbol.HasAttributeWithFullyQualifiedMetadataName("CommunityToolkit.Mvvm.ComponentModel.NotifyDataErrorInfoAttribute"))
+            if (context.Compilation.GetTypeByMetadataName("CommunityToolkit.Mvvm.ComponentModel.NotifyDataErrorInfoAttribute") is not INamedTypeSymbol notifyDataErrorInfoAttributeSymbol ||
+                !classSymbol.HasAttributeWithType(notifyDataErrorInfoAttributeSymbol))
             {
                 return;
             }
 
             // If the containing type is not valid, emit a diagnostic
-            if (!classSymbol.InheritsFromFullyQualifiedMetadataName("CommunityToolkit.Mvvm.ComponentModel.ObservableValidator"))
+            if (context.Compilation.GetTypeByMetadataName("CommunityToolkit.Mvvm.ComponentModel.ObservableValidator") is not INamedTypeSymbol observableValidatorSymbol ||
+                !classSymbol.InheritsFromType(observableValidatorSymbol))
             {
                 context.ReportDiagnostic(Diagnostic.Create(
                     InvalidTypeForNotifyDataErrorInfoError,

src/CommunityToolkit.Mvvm.SourceGenerators/Diagnostics/Analyzers/InvalidClassLevelNotifyPropertyChangedRecipientsAttributeAnalyzer.cs

@@ -35,14 +35,17 @@ public override void Initialize(AnalysisContext context)
             }
 
             // Only inspect classes that are using [NotifyPropertyChangedRecipients]
-            if (!classSymbol.HasAttributeWithFullyQualifiedMetadataName("CommunityToolkit.Mvvm.ComponentModel.NotifyPropertyChangedRecipientsAttribute"))
+            if (context.Compilation.GetTypeByMetadataName("CommunityToolkit.Mvvm.ComponentModel.NotifyPropertyChangedRecipientsAttribute") is not INamedTypeSymbol notifyPropertyChangedRecipientsAttributeSymbol ||
+                !classSymbol.HasAttributeWithType(notifyPropertyChangedRecipientsAttributeSymbol))
             {
                 return;
             }
 
             // If the containing type is not valid, emit a diagnostic
-            if (!classSymbol.InheritsFromFullyQualifiedMetadataName("CommunityToolkit.Mvvm.ComponentModel.ObservableRecipient") &&
-                !classSymbol.HasOrInheritsAttributeWithFullyQualifiedMetadataName("CommunityToolkit.Mvvm.ComponentModel.ObservableRecipientAttribute"))
+            if (context.Compilation.GetTypeByMetadataName("CommunityToolkit.Mvvm.ComponentModel.ObservableRecipient") is INamedTypeSymbol observableRecipientSymbol &&
+                context.Compilation.GetTypeByMetadataName("CommunityToolkit.Mvvm.ComponentModel.ObservableRecipientAttribute") is INamedTypeSymbol observableRecipientAttributeSymbol &&
+                !classSymbol.InheritsFromType(observableRecipientSymbol) &&
+                !classSymbol.HasOrInheritsAttributeWithType(observableRecipientAttributeSymbol))
             {
                 context.ReportDiagnostic(Diagnostic.Create(
                     InvalidTypeForNotifyPropertyChangedRecipientsError,

src/CommunityToolkit.Mvvm.SourceGenerators/Extensions/ISymbolExtensions.cs

@@ -2,7 +2,6 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-using System.Collections.Immutable;
 #if !ROSLYN_4_3_1_OR_GREATER
 using System.Diagnostics.CodeAnalysis;
 #endif
@@ -54,9 +53,7 @@ public static bool HasFullyQualifiedName(this ISymbol symbol, string name)
     /// <returns>Whether or not <paramref name="symbol"/> has an attribute with the specified name.</returns>
     public static bool HasAttributeWithFullyQualifiedMetadataName(this ISymbol symbol, string name)
     {
-        ImmutableArray<AttributeData> attributes = symbol.GetAttributes();
-
-        foreach (AttributeData attribute in attributes)
+        foreach (AttributeData attribute in symbol.GetAttributes())
         {
             if (attribute.AttributeClass?.HasFullyQualifiedMetadataName(name) == true)
             {
@@ -67,6 +64,25 @@ public static bool HasAttributeWithFullyQualifiedMetadataName(this ISymbol symbo
         return false;
     }
 
+    /// <summary>
+    /// Checks whether or not a given symbol has an attribute with the specified fully qualified metadata name.
+    /// </summary>
+    /// <param name="symbol">The input <see cref="ISymbol"/> instance to check.</param>
+    /// <param name="typeSymbol">The <see cref="ITypeSymbol"/> instance for the attribute type to look for.</param>
+    /// <returns>Whether or not <paramref name="symbol"/> has an attribute with the specified type.</returns>
+    public static bool HasAttributeWithType(this ISymbol symbol, ITypeSymbol typeSymbol)
+    {
+        foreach (AttributeData attribute in symbol.GetAttributes())
+        {
+            if (SymbolEqualityComparer.Default.Equals(attribute.AttributeClass, typeSymbol))
+            {
+                return true;
+            }
+        }
+
+        return false;
+    }
+
 #if !ROSLYN_4_3_1_OR_GREATER
     /// <summary>
     /// Tries to get an attribute with the specified fully qualified metadata name.
@@ -77,9 +93,7 @@ public static bool HasAttributeWithFullyQualifiedMetadataName(this ISymbol symbo
     /// <returns>Whether or not <paramref name="symbol"/> has an attribute with the specified name.</returns>
     public static bool TryGetAttributeWithFullyQualifiedMetadataName(this ISymbol symbol, string name, [NotNullWhen(true)] out AttributeData? attributeData)
     {
-        ImmutableArray<AttributeData> attributes = symbol.GetAttributes();
-
-        foreach (AttributeData attribute in attributes)
+        foreach (AttributeData attribute in symbol.GetAttributes())
         {
             if (attribute.AttributeClass?.HasFullyQualifiedMetadataName(name) == true)
             {

src/CommunityToolkit.Mvvm.SourceGenerators/Extensions/ITypeSymbolExtensions.cs

@@ -43,7 +43,7 @@ public static bool InheritsFromFullyQualifiedMetadataName(this ITypeSymbol typeS
     {
         INamedTypeSymbol? baseType = typeSymbol.BaseType;
 
-        while (baseType != null)
+        while (baseType is not null)
         {
             if (baseType.HasFullyQualifiedMetadataName(name))
             {
@@ -56,6 +56,29 @@ public static bool InheritsFromFullyQualifiedMetadataName(this ITypeSymbol typeS
         return false;
     }
 
+    /// <summary>
+    /// Checks whether or not a given <see cref="ITypeSymbol"/> inherits from a specified type.
+    /// </summary>
+    /// <param name="typeSymbol">The target <see cref="ITypeSymbol"/> instance to check.</param>
+    /// <param name="baseTypeSymbol">The <see cref="ITypeSymbol"/> instane to check for inheritance from.</param>
+    /// <returns>Whether or not <paramref name="typeSymbol"/> inherits from <paramref name="baseTypeSymbol"/>.</returns>
+    public static bool InheritsFromType(this ITypeSymbol typeSymbol, ITypeSymbol baseTypeSymbol)
+    {
+        INamedTypeSymbol? currentBaseTypeSymbol = typeSymbol.BaseType;
+
+        while (currentBaseTypeSymbol is not null)
+        {
+            if (SymbolEqualityComparer.Default.Equals(currentBaseTypeSymbol, baseTypeSymbol))
+            {
+                return true;
+            }
+
+            currentBaseTypeSymbol = currentBaseTypeSymbol.BaseType;
+        }
+
+        return false;
+    }
+
     /// <summary>
     /// Checks whether or not a given <see cref="ITypeSymbol"/> implements an interface with a specified name.
     /// </summary>
@@ -113,6 +136,25 @@ public static bool HasOrInheritsAttributeWithFullyQualifiedMetadataName(this ITy
         return false;
     }
 
+    /// <summary>
+    /// Checks whether or not a given <see cref="ITypeSymbol"/> has or inherits a specified attribute.
+    /// </summary>
+    /// <param name="typeSymbol">The target <see cref="ITypeSymbol"/> instance to check.</param>
+    /// <param name="baseTypeSymbol">The <see cref="ITypeSymbol"/> instane to check for inheritance from.</param>
+    /// <returns>Whether or not <paramref name="typeSymbol"/> has or inherits an attribute of type <paramref name="baseTypeSymbol"/>.</returns>
+    public static bool HasOrInheritsAttributeWithType(this ITypeSymbol typeSymbol, ITypeSymbol baseTypeSymbol)
+    {
+        for (ITypeSymbol? currentType = typeSymbol; currentType is not null; currentType = currentType.BaseType)
+        {
+            if (currentType.HasAttributeWithType(baseTypeSymbol))
+            {
+                return true;
+            }
+        }
+
+        return false;
+    }
+
     /// <summary>
     /// Checks whether or not a given <see cref="ITypeSymbol"/> inherits a specified attribute.
     /// If the type has no base type, this method will automatically handle that and return <see langword="false"/>.