Treat Type and MemberInfo as well-known types in structural equivalency comparisons

[Copilot]

IsEquivalentTo throws InvalidOperationException when comparing records with Type properties. RuntimeType.DeclaringMethod (among others) throws when accessed on non-generic-parameter types, and the structural comparison walks all public properties.

public record Record(Type Type);

var r = new Record(typeof(string));
await Assert.That(r).IsEquivalentTo(r); // throws InvalidOperationException

Changes

• TypeHelper.IsPrimitiveOrWellKnownType: Added typeof(Type).IsAssignableFrom(type) and typeof(MemberInfo).IsAssignableFrom(type) so reflection types are compared by equality rather than structurally decomposed. Uses IsAssignableFrom to catch runtime subtypes like RuntimeType.
• Regression tests: Added IsEquivalentTo_TypeProperty_Tests covering same-instance, equal, and different Type property scenarios.

Original prompt

---

This section details on the original issue you should resolve

<issue_title>[Bug]: InvalidOperationException when using IsEquivalentTo for records with Type properties</issue_title>
<issue_description>### Description

This will throw InvalidOperationException:

public record Record(Type Type);

public class Foo
{
    [Test]
    public async Task Bar()
    {
        var r = new Record(typeof(string));
        await Assert.That(r).IsEquivalentTo(r);
    }
}

<Project Sdk="Microsoft.NET.Sdk">

    <PropertyGroup>
        <OutputType>Exe</OutputType>
        <TargetFramework>net10.0</TargetFramework>
        <ImplicitUsings>enable</ImplicitUsings>
        <Nullable>enable</Nullable>
    </PropertyGroup>

    <ItemGroup>
      <PackageReference Include="TUnit" Version="1.13.11" />
    </ItemGroup>

</Project>

Expected Behavior

The test should pass

Actual Behavior

Test fails

Steps to Reproduce

See description

TUnit Version

1.13.11

.NET Version

net10.0

Operating System

macOS

IDE / Test Runner

JetBrains Rider

Error Output / Stack Trace

System.Reflection.TargetInvocationException: Exception has been thrown by the target of an invocation.
 ---> System.InvalidOperationException: Method may only be called on a Type for which Type.IsGenericParameter is true.
   at System.RuntimeType.get_DeclaringMethod()
   at InvokeStub_RuntimeType.get_DeclaringMethod(Object, Object, IntPtr*)
   at System.Reflection.MethodBaseInvoker.InvokeWithNoArgs(Object obj, BindingFlags invokeAttr)
   --- End of inner exception stack trace ---
   at System.Reflection.MethodBaseInvoker.InvokeWithNoArgs(Object obj, BindingFlags invokeAttr)
   at System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture)
   at TUnit.Assertions.Conditions.Helpers.ReflectionHelper.GetMemberValue(Object obj, MemberInfo member)
   at TUnit.Assertions.Conditions.StructuralEquivalencyAssertion`1.CompareObjects(Object actual, Object expected, String path, HashSet`1 visitedActual, HashSet`1 visitedExpected)
   at TUnit.Assertions.Conditions.StructuralEquivalencyAssertion`1.CompareObjects(Object actual, Object expected, String path, HashSet`1 visitedActual, HashSet`1 visitedExpected)
   at TUnit.Assertions.Conditions.StructuralEquivalencyAssertion`1.CheckAsync(EvaluationMetadata`1 metadata)
   at TUnit.Assertions.Core.Assertion`1.CreateMetadataAndCheckAsync(TValue value, Exception exception)
   at TUnit.Assertions.Core.Assertion`1.ExecuteCoreAsync()
   at TUnit.Assertions.Core.Assertion`1.AssertAsync()
   at Foo.Bar() in /Users/alex/Projects/ConsoleApp1/ConsoleApp1/Program.cs:line 9

Additional Context

No response

IDE-Specific Issue?

• I've confirmed this issue occurs when running via dotnet test or dotnet run, not just in my IDE</issue_description>

Comments on the Issue (you are @copilot in this section)

• Fixes [Bug]: InvalidOperationException when using IsEquivalentTo for records with Type properties #4700

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[claude]

Code review

No issues found. Checked for bugs and CLAUDE.md compliance.

This is a well-crafted bug fix that:

• Correctly addresses the root cause by treating Type and MemberInfo as well-known types
• Uses IsAssignableFrom appropriately to catch runtime subtypes like RuntimeType
• Includes comprehensive regression tests covering key scenarios
• Makes a minimal, surgical change without over-engineering
• Complies with all CLAUDE.md rules (dual-mode not applicable for assertions, no public API changes requiring snapshots, AOT-compatible, no performance concerns)