Error when loading external assemblies

[sirosimo]

Working on an app migration form .Net Framework 4.8 to .Net 6, I'm facing an issue when trying to registered external assemblies from a certain folder.

container.Register(
        Classes.FromAssemblyInDirectory(new AssemblyFilter("Peoples"))
        .BasedOn<IPersonBase>()
        .WithServiceFromInterface() );

Here is an example project that highlight the issue: https://github.com/sirosimo/CastleSandBox.git

The external assemblies and classes implementing IPersonBase aren't referenced in the main application and may be in a different namespace.
In the framework version, this code work good, but when switching to .Net 6, I encounter FileNotFoundException when trying to load the assemblies.

Probable Cause:
I think I tracked down the issue to [Core.Internal.ReflectionUtil.cs line 136] (https://github.com/castleproject/Windsor/blob/master/src/Castle.Windsor/Core/Internal/ReflectionUtil.cs#:~:text=var%20assembly%20%3D%20LoadAssembly(assemblyName)%3B) and more precisely System.Reflection.Assembly

The assembly is loaded using the assembly name as opposed to the assembly file path. When using only the assembly name (Assembly.Load(assemblyName)) it results with a FileNotFoundException as the assembly name isn't referenced in the main application

Possible Solution:

Add an extra method to ReflectionUtil, using LoadFrom() instead of Load():

private static Assembly LoadAssembly(string assemblyFilePath){
return Assembly.LoadFrom(assemblyFilePath);
}

And change the way the assembly are being loaded to always refer to the filePath if available:

public static Assembly GetAssemblyNamed(string filePath, Predicate<AssemblyName> nameFilter, Predicate<Assembly> assemblyFilter){
var assemblyName = GetAssemblyName(filePath);
if (nameFilter != null)
	foreach (Predicate<AssemblyName> predicate in nameFilter.GetInvocationList())
		if (predicate(assemblyName) == false) return null;
				
var assembly = LoadAssembly(filePath);
if (assemblyFilter != null)
	foreach (Predicate<Assembly> predicate in assemblyFilter.GetInvocationList())
		if (predicate(assembly) == false) return null;

return assembly;
}

I tested it and it pass all the Castle.Windsor.Test

Thank you

Castle.Windsor 5.1.2
Castle.Core 4.1.1

[Jevonius]

Hey @sirosimo, sounds like a variant of dotnet/runtime#13511 - it appears to be a .Net Core issue rather than .Net 6 specifically from some brief Linqpad testing.

There might be some work to be done around FEATURE_ASSEMBLIES:

FEATURE_ASSEMBLIES - uses AssemblyName.GetAssemblyName() and Assembly.LoadFile().

For the .net standard build (which your .net 6 target will be using), FEATURE_ASSEMBLIES isn't set, but it seems for .net Core/5/6 it perhaps should be.

[Jevonius]

-- Edited out my wrong code :) --

There might be a similar issue with the method public static Assembly GetAssemblyNamed(string assemblyName) - looking at it, this is doing some form of detection for DLLs in the same folder as AppContext.BaseDirectory but that might need checking. There's two different code paths doing very similar things, but differently here, so would be nice to align them.