BeEquivalentTo will now find and can map subject properties that are …

…implemented through an explicitly-implemented interface

Src/FluentAssertions/Common/TypeExtensions.cs

@@ -15,9 +15,6 @@ internal static class TypeExtensions
     private const BindingFlags PublicInstanceMembersFlag =
         BindingFlags.Public | BindingFlags.Instance;
 
-    private const BindingFlags AllInstanceMembersFlag =
-        BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.Instance;
-
     private const BindingFlags AllStaticAndInstanceMembersFlag =
         PublicInstanceMembersFlag | BindingFlags.NonPublic | BindingFlags.Static;
 
@@ -176,24 +173,21 @@ public static bool OverridesEquals(this Type type)
     }
 
     /// <summary>
-    /// Finds the property by a case-sensitive name.
+    /// Finds the property by a case-sensitive name and with a certain visibility.
     /// </summary>
+    /// <remarks>
+    /// If both a normal property and one that was implemented through an explicit interface implementation with the same name exist,
+    /// then the normal property will be returned.
+    /// </remarks>
     /// <returns>
     /// Returns <see langword="null"/> if no such property exists.
     /// </returns>
-    public static PropertyInfo FindProperty(this Type type, string propertyName)
+    public static PropertyInfo FindProperty(this Type type, string propertyName, MemberVisibility memberVisibility)
     {
-        while (type != typeof(object))
-        {
-            if (type.GetProperty(propertyName, AllInstanceMembersFlag | BindingFlags.DeclaredOnly) is { } property)
-            {
-                return property;
-            }
-
-            type = type.BaseType;
-        }
+        var properties = type.GetNonPrivateProperties(memberVisibility);
 
-        return null;
+        return Array.Find(properties, p =>
+            p.Name == propertyName || p.Name.EndsWith("." + propertyName, StringComparison.OrdinalIgnoreCase));
     }
 
     /// <summary>
@@ -202,19 +196,12 @@ public static PropertyInfo FindProperty(this Type type, string propertyName)
     /// <returns>
     /// Returns <see langword="null"/> if no such property exists.
     /// </returns>
-    public static FieldInfo FindField(this Type type, string fieldName)
+    public static FieldInfo FindField(this Type type, string fieldName, MemberVisibility memberVisibility)
     {
-        while (type != typeof(object))
-        {
-            if (type.GetField(fieldName, AllInstanceMembersFlag | BindingFlags.DeclaredOnly) is { } field)
-            {
-                return field;
-            }
+        var fields = type.GetNonPrivateFields(memberVisibility);
 
-            type = type.BaseType;
-        }
-
-        return null;
+        return Array.Find(fields, p =>
+            p.Name == fieldName || p.Name.EndsWith("." + fieldName, StringComparison.OrdinalIgnoreCase));
     }
 
     public static MemberInfo[] GetNonPrivateMembers(this Type typeToReflect, MemberVisibility visibility)
@@ -318,8 +305,11 @@ public static bool IsIndexer(this PropertyInfo member)
 
     public static ConstructorInfo GetConstructor(this Type type, IEnumerable<Type> parameterTypes)
     {
+        const BindingFlags allInstanceMembersFlag =
+            BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.Instance;
+
         return type
-            .GetConstructors(AllInstanceMembersFlag)
+            .GetConstructors(allInstanceMembersFlag)
             .SingleOrDefault(m => m.GetParameters().Select(p => p.ParameterType).SequenceEqual(parameterTypes));
     }
 

Src/FluentAssertions/Common/TypeMemberReflector.cs

@@ -31,27 +31,45 @@ private static PropertyInfo[] LoadNonPrivateProperties(Type typeToReflect, Membe
     {
         IEnumerable<PropertyInfo> query =
             from propertyInfo in GetPropertiesFromHierarchy(typeToReflect, visibility)
-            where HasNonPrivateGetter(propertyInfo)
+            where HasNonPrivateGetter(propertyInfo, visibility)
             where !propertyInfo.IsIndexer()
             select propertyInfo;
 
         return query.ToArray();
     }
 
-    private static List<PropertyInfo> GetPropertiesFromHierarchy(Type typeToReflect, MemberVisibility memberVisibility)
+    private static PropertyInfo[] GetPropertiesFromHierarchy(Type typeToReflect, MemberVisibility memberVisibility)
     {
-        bool includeInternals = memberVisibility.HasFlag(MemberVisibility.Internal);
+        bool includeInternal = memberVisibility.HasFlag(MemberVisibility.Internal);
 
         return GetMembersFromHierarchy(typeToReflect, type =>
         {
             return type
                 .GetProperties(AllInstanceMembersFlag | BindingFlags.DeclaredOnly)
-                .Where(property => property.GetMethod?.IsPrivate == false)
-                .Where(property => includeInternals || property.GetMethod is { IsAssembly: false, IsFamilyOrAssembly: false })
+                .Where(property => includeInternal || !IsInternal(property))
+                .Select(property => new
+                {
+                    Property = property,
+                    IsExplicit = IsExplicitImplementation(property)
+                })
+                .OrderBy(x => x.IsExplicit)
+                .Select(x => x.Property)
                 .ToArray();
         });
     }
 
+    private static bool IsInternal(PropertyInfo property)
+    {
+        return property.GetMethod is { IsAssembly: true } or { IsFamilyOrAssembly: true };
+    }
+
+    private static bool IsExplicitImplementation(PropertyInfo property)
+    {
+        return property.GetMethod?.IsPrivate == true &&
+            property.SetMethod?.IsPrivate == true &&
+            property.Name.Contains('.', StringComparison.Ordinal);
+    }
+
     private static FieldInfo[] LoadNonPrivateFields(Type typeToReflect, MemberVisibility visibility)
     {
         IEnumerable<FieldInfo> query =
@@ -63,21 +81,26 @@ from fieldInfo in GetFieldsFromHierarchy(typeToReflect, visibility)
         return query.ToArray();
     }
 
-    private static List<FieldInfo> GetFieldsFromHierarchy(Type typeToReflect, MemberVisibility memberVisibility)
+    private static FieldInfo[] GetFieldsFromHierarchy(Type typeToReflect, MemberVisibility memberVisibility)
     {
-        bool includeInternals = memberVisibility.HasFlag(MemberVisibility.Internal);
+        bool includeInternal = memberVisibility.HasFlag(MemberVisibility.Internal);
 
         return GetMembersFromHierarchy(typeToReflect, type =>
         {
             return type
                 .GetFields(AllInstanceMembersFlag)
                 .Where(field => !field.IsPrivate)
-                .Where(field => includeInternals || (!field.IsAssembly && !field.IsFamilyOrAssembly))
+                .Where(field => includeInternal || !IsInternal(field))
                 .ToArray();
         });
     }
 
-    private static List<TMemberInfo> GetMembersFromHierarchy<TMemberInfo>(
+    private static bool IsInternal(FieldInfo field)
+    {
+        return field.IsAssembly || field.IsFamilyOrAssembly;
+    }
+
+    private static TMemberInfo[] GetMembersFromHierarchy<TMemberInfo>(
         Type typeToReflect,
         Func<Type, IEnumerable<TMemberInfo>> getMembers)
         where TMemberInfo : MemberInfo
@@ -90,7 +113,7 @@ private static List<TMemberInfo> GetMembersFromHierarchy<TMemberInfo>(
         return GetClassMembers(typeToReflect, getMembers);
     }
 
-    private static List<TMemberInfo> GetInterfaceMembers<TMemberInfo>(Type typeToReflect,
+    private static TMemberInfo[] GetInterfaceMembers<TMemberInfo>(Type typeToReflect,
         Func<Type, IEnumerable<TMemberInfo>> getMembers)
         where TMemberInfo : MemberInfo
     {
@@ -123,10 +146,10 @@ private static List<TMemberInfo> GetInterfaceMembers<TMemberInfo>(Type typeToRef
             members.InsertRange(0, newPropertyInfos);
         }
 
-        return members;
+        return members.ToArray();
     }
 
-    private static List<TMemberInfo> GetClassMembers<TMemberInfo>(Type typeToReflect,
+    private static TMemberInfo[] GetClassMembers<TMemberInfo>(Type typeToReflect,
         Func<Type, IEnumerable<TMemberInfo>> getMembers)
         where TMemberInfo : MemberInfo
     {
@@ -145,12 +168,18 @@ private static List<TMemberInfo> GetClassMembers<TMemberInfo>(Type typeToReflect
             typeToReflect = typeToReflect.BaseType;
         }
 
-        return members;
+        return members.ToArray();
     }
 
-    private static bool HasNonPrivateGetter(PropertyInfo propertyInfo)
+    private static bool HasNonPrivateGetter(PropertyInfo propertyInfo, MemberVisibility visibility)
     {
         MethodInfo getMethod = propertyInfo.GetGetMethod(nonPublic: true);
+
+        if (visibility.HasFlag(MemberVisibility.ExplicitlyImplemented))
+        {
+            return getMethod is { IsPrivate: false, IsFamily: false } or { IsPrivate: true, IsFinal: true };
+        }
+
         return getMethod is { IsPrivate: false, IsFamily: false };
     }
 }

Src/FluentAssertions/Equivalency/Matching/MustMatchByNameRule.cs

@@ -15,19 +15,20 @@ public IMember Match(IMember expectedMember, object subject, INode parent, IEqui
 
         if (options.IncludedProperties != MemberVisibility.None)
         {
-            PropertyInfo propertyInfo = subject.GetType().FindProperty(expectedMember.Name);
+            PropertyInfo propertyInfo = subject.GetType().FindProperty(
+                expectedMember.Name,
+                options.IncludedProperties | MemberVisibility.ExplicitlyImplemented);
+
             subjectMember = propertyInfo is not null && !propertyInfo.IsIndexer() ? new Property(propertyInfo, parent) : null;
         }
 
         if (subjectMember is null && options.IncludedFields != MemberVisibility.None)
         {
-            FieldInfo fieldInfo = subject.GetType().FindField(expectedMember.Name);
-            subjectMember = fieldInfo is not null ? new Field(fieldInfo, parent) : null;
-        }
+            FieldInfo fieldInfo = subject.GetType().FindField(
+                expectedMember.Name,
+                options.IncludedFields);
 
-        if ((subjectMember is null || !options.UseRuntimeTyping) && ExpectationImplementsMemberExplicitly(subject, expectedMember))
-        {
-            subjectMember = expectedMember;
+            subjectMember = fieldInfo is not null ? new Field(fieldInfo, parent) : null;
         }
 
         if (subjectMember is null)
@@ -49,11 +50,6 @@ public IMember Match(IMember expectedMember, object subject, INode parent, IEqui
         return subjectMember;
     }
 
-    private static bool ExpectationImplementsMemberExplicitly(object expectation, IMember subjectMember)
-    {
-        return subjectMember.DeclaringType.IsInstanceOfType(expectation);
-    }
-
     /// <inheritdoc />
     /// <filterpriority>2</filterpriority>
     public override string ToString()

Src/FluentAssertions/Equivalency/Matching/TryMatchByNameRule.cs

@@ -10,14 +10,17 @@ internal class TryMatchByNameRule : IMemberMatchingRule
 {
     public IMember Match(IMember expectedMember, object subject, INode parent, IEquivalencyAssertionOptions options)
     {
-        PropertyInfo property = subject.GetType().FindProperty(expectedMember.Name);
+        PropertyInfo property = subject.GetType().FindProperty(expectedMember.Name,
+            options.IncludedProperties | MemberVisibility.ExplicitlyImplemented);
 
         if (property is not null && !property.IsIndexer())
         {
             return new Property(property, parent);
         }
 
-        FieldInfo field = subject.GetType().FindField(expectedMember.Name);
+        FieldInfo field = subject.GetType()
+            .FindField(expectedMember.Name, options.IncludedFields);
+
         return field is not null ? new Field(field, parent) : null;
     }
 

Src/FluentAssertions/Equivalency/MemberFactory.cs

@@ -18,14 +18,14 @@ public static IMember Create(MemberInfo memberInfo, INode parent)
 
     internal static IMember Find(object target, string memberName, INode parent)
     {
-        PropertyInfo property = target.GetType().FindProperty(memberName);
+        PropertyInfo property = target.GetType().FindProperty(memberName, MemberVisibility.Public | MemberVisibility.ExplicitlyImplemented);
 
         if (property is not null && !property.IsIndexer())
         {
             return new Property(property, parent);
         }
 
-        FieldInfo field = target.GetType().FindField(memberName);
+        FieldInfo field = target.GetType().FindField(memberName, MemberVisibility.Public);
         return field is not null ? new Field(field, parent) : null;
     }
 }

Src/FluentAssertions/Equivalency/MemberVisibility.cs

@@ -11,5 +11,6 @@ public enum MemberVisibility
 {
     None = 0,
     Internal = 1,
-    Public = 2
+    Public = 2,
+    ExplicitlyImplemented = 4
 }

Tests/Approval.Tests/ApiApproval.cs

@@ -28,10 +28,12 @@ public Task ApproveApi(string frameworkVersion)
         string assemblyPath = Uri.UnescapeDataString(uri.Path);
         var containingDirectory = Path.GetDirectoryName(assemblyPath);
         var configurationName = new DirectoryInfo(containingDirectory).Parent.Name;
+
         var assemblyFile = Path.GetFullPath(
             Path.Combine(
                 GetSourceDirectory(),
-                Path.Combine("..", "..", "Src", "FluentAssertions", "bin", configurationName, frameworkVersion, "FluentAssertions.dll")));
+                Path.Combine("..", "..", "Src", "FluentAssertions", "bin", configurationName, frameworkVersion,
+                    "FluentAssertions.dll")));
 
         var assembly = Assembly.LoadFile(Path.GetFullPath(assemblyFile));
         var publicApi = assembly.GeneratePublicApi(options: null);
@@ -53,6 +55,7 @@ public static Task<CompareResult> OnlyIncludeChanges(string received, string ver
         var diff = InlineDiffBuilder.Diff(verified, received);
 
         var builder = new StringBuilder();
+
         foreach (var line in diff.Lines)
         {
             switch (line.Type)
@@ -79,9 +82,12 @@ private class TargetFrameworksTheoryData : TheoryData<string>
     {
         public TargetFrameworksTheoryData()
         {
-            var csproj = Path.Combine(GetSourceDirectory(), Path.Combine("..", "..", "Src", "FluentAssertions", "FluentAssertions.csproj"));
+            var csproj = Path.Combine(GetSourceDirectory(),
+                Path.Combine("..", "..", "Src", "FluentAssertions", "FluentAssertions.csproj"));
+
             var project = XDocument.Load(csproj);
             var targetFrameworks = project.XPathSelectElement("/Project/PropertyGroup/TargetFrameworks");
+
             foreach (string targetFramework in targetFrameworks!.Value.Split(';'))
             {
                 Add(targetFramework);

Tests/Approval.Tests/ApprovedApi/FluentAssertions/net47.verified.txt

@@ -972,6 +972,7 @@ namespace FluentAssertions.Equivalency
         None = 0,
         Internal = 1,
         Public = 2,
+        ExplicitlyImplemented = 4,
     }
     public class NestedExclusionOptionBuilder<TExpectation, TCurrent>
     {

Tests/Approval.Tests/ApprovedApi/FluentAssertions/net6.0.verified.txt

@@ -985,6 +985,7 @@ namespace FluentAssertions.Equivalency
         None = 0,
         Internal = 1,
         Public = 2,
+        ExplicitlyImplemented = 4,
     }
     public class NestedExclusionOptionBuilder<TExpectation, TCurrent>
     {

Tests/Approval.Tests/ApprovedApi/FluentAssertions/netcoreapp2.1.verified.txt

@@ -972,6 +972,7 @@ namespace FluentAssertions.Equivalency
         None = 0,
         Internal = 1,
         Public = 2,
+        ExplicitlyImplemented = 4,
     }
     public class NestedExclusionOptionBuilder<TExpectation, TCurrent>
     {

Tests/Approval.Tests/ApprovedApi/FluentAssertions/netcoreapp3.0.verified.txt

@@ -972,6 +972,7 @@ namespace FluentAssertions.Equivalency
         None = 0,
         Internal = 1,
         Public = 2,
+        ExplicitlyImplemented = 4,
     }
     public class NestedExclusionOptionBuilder<TExpectation, TCurrent>
     {

Tests/Approval.Tests/ApprovedApi/FluentAssertions/netstandard2.0.verified.txt

@@ -965,6 +965,7 @@ namespace FluentAssertions.Equivalency
         None = 0,
         Internal = 1,
         Public = 2,
+        ExplicitlyImplemented = 4,
     }
     public class NestedExclusionOptionBuilder<TExpectation, TCurrent>
     {

Tests/Approval.Tests/ApprovedApi/FluentAssertions/netstandard2.1.verified.txt

@@ -972,6 +972,7 @@ namespace FluentAssertions.Equivalency
         None = 0,
         Internal = 1,
         Public = 2,
+        ExplicitlyImplemented = 4,
     }
     public class NestedExclusionOptionBuilder<TExpectation, TCurrent>
     {