Treat record structs as records

Src/FluentAssertions/Common/TypeExtensions.cs

@@ -584,12 +584,18 @@ private static bool IsAnonymousType(this Type type)
     public static bool IsRecord(this Type type)
     {
         return TypeIsRecordCache.GetOrAdd(type, static t =>
-            t.GetMethod("<Clone>$") is not null &&
-            t.GetTypeInfo()
-                 .DeclaredProperties
-                 .FirstOrDefault(p => p.Name == "EqualityContract")?
-                 .GetMethod?
-                 .GetCustomAttribute(typeof(CompilerGeneratedAttribute)) is not null);
+        {
+            bool isRecord = t.GetMethod("<Clone>$") is not null &&
+                            t.GetTypeInfo()
+                                .DeclaredProperties
+                                .FirstOrDefault(p => p.Name == "EqualityContract")?
+                                .GetMethod?
+                                .GetCustomAttribute(typeof(CompilerGeneratedAttribute)) is not null;
+            bool isRecordStruct = t.BaseType == typeof(ValueType) &&
+                                  t.GetMethods().Where(m => m.Name == "op_Inequality").SelectMany(m => m.GetCustomAttributes(typeof(CompilerGeneratedAttribute))).Any() &&
+                                  t.GetMethods().Where(m => m.Name == "op_Equality").SelectMany(m => m.GetCustomAttributes(typeof(CompilerGeneratedAttribute))).Any();
+            return isRecord || isRecordStruct;
+        });
     }
 
     private static bool IsKeyValuePair(Type type)

Tests/FluentAssertions.Equivalency.Specs/RecordSpecs.cs

@@ -16,6 +16,16 @@ public void When_the_subject_is_a_record_it_should_compare_it_by_its_members()
         actual.Should().BeEquivalentTo(expected);
     }
 
+    [Fact]
+    public void When_the_subject_is_a_readonly_record_struct_it_should_compare_it_by_its_members()
+    {
+        var actual = new MyReadonlyRecordStruct("foo", new[] { "bar", "zip", "foo" });
+
+        var expected = new MyReadonlyRecordStruct("foo", new[] { "bar", "zip", "foo" });
+
+        actual.Should().BeEquivalentTo(expected);
+    }
+
     [Fact]
     public void When_the_subject_is_a_record_it_should_mention_that_in_the_configuration_output()
     {
@@ -90,4 +100,9 @@ private record MyRecord
 
         public string[] CollectionProperty { get; init; }
     }
+
+    private readonly record struct MyReadonlyRecordStruct(string StringField, string[] CollectionProperty)
+    {
+        public readonly string StringField = StringField;
+    }
 }

Tests/FluentAssertions.Specs/Types/TypeExtensionsSpecs.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Collections.Immutable;
 using System.Linq;
 using System.Reflection;
 using FluentAssertions.Common;
@@ -124,6 +125,33 @@ public void When_getting_fake_implicit_conversion_operator_from_a_type_with_fake
         result.Should().NotBeNull();
     }
 
+    [Theory]
+    [InlineData(typeof(MyRecord), true)]
+    [InlineData(typeof(MyRecordStruct), true)]
+    [InlineData(typeof(MyRecordStructWithOverriddenEquality), true)]
+    [InlineData(typeof(MyReadonlyRecordStruct), true)]
+    [InlineData(typeof(MyStruct), false)]
+    [InlineData(typeof(MyStructWithOverriddenEquality), false)]
+    [InlineData(typeof(MyClass), false)]
+    [InlineData(typeof(int), false)]
+    [InlineData(typeof(string), false)]
+    public void IsRecord_should_detect_records_correctly(Type type, bool expected)
+    {
+        type.IsRecord().Should().Be(expected);
+    }
+
+    [Fact]
+    public void When_checking_if_anonymous_type_is_record_it_should_return_false()
+    {
+        new { Value = 42 }.GetType().IsRecord().Should().Be(false);
+    }
+
+    [Fact]
+    public void When_checking_if_class_with_multiple_equality_methods_is_record_it_should_return_false()
+    {
+        typeof(ImmutableArray<int>).IsRecord().Should().Be(false);
+    }
+
     private static MethodInfo GetFakeConversionOperator(Type type, string name, BindingFlags bindingAttr, Type returnType)
     {
         MethodInfo[] methods = type.GetMethods(bindingAttr);
@@ -153,4 +181,42 @@ private TypeWithFakeConversionOperators(int value)
         public static byte op_Explicit(TypeWithFakeConversionOperators typeWithFakeConversionOperators) => (byte)typeWithFakeConversionOperators.value;
 #pragma warning restore SA1300, IDE1006
     }
+
+    private record MyRecord(int Value);
+
+    private record struct MyRecordStruct(int Value);
+
+    private record struct MyRecordStructWithOverriddenEquality(int Value)
+    {
+        public bool Equals(MyRecordStructWithOverriddenEquality other) => Value == other.Value;
+
+        public override int GetHashCode() => Value;
+    }
+
+    private readonly record struct MyReadonlyRecordStruct(int Value);
+
+    private struct MyStruct
+    {
+        public int Value { get; set; }
+    }
+
+    private struct MyStructWithOverriddenEquality : IEquatable<MyStructWithOverriddenEquality>
+    {
+        public int Value { get; set; }
+
+        public bool Equals(MyStructWithOverriddenEquality other) => Value == other.Value;
+
+        public override bool Equals(object obj) => obj is MyStructWithOverriddenEquality other && Equals(other);
+
+        public override int GetHashCode() => Value;
+
+        public static bool operator ==(MyStructWithOverriddenEquality left, MyStructWithOverriddenEquality right) => left.Equals(right);
+
+        public static bool operator !=(MyStructWithOverriddenEquality left, MyStructWithOverriddenEquality right) => !left.Equals(right);
+    }
+
+    private class MyClass
+    {
+        public int Value { get; set; }
+    }
 }