DependencyAssemblyLoadContext.cs

using System;
using System.Collections.Concurrent;
using System.Collections.Generic;
using System.IO;
using System.Management.Automation;
using System.Reflection;
using System.Runtime.Loader;
using System.Text;

namespace PnP.PowerShell.Commands
{
    public class DependencyAssemblyLoadContext : AssemblyLoadContext
    {
        private static readonly string s_psHome = Path.GetDirectoryName(Assembly.GetEntryAssembly().Location);

        private static readonly ConcurrentDictionary<string, DependencyAssemblyLoadContext> s_dependencyLoadContexts = new ConcurrentDictionary<string, DependencyAssemblyLoadContext>();

        internal static DependencyAssemblyLoadContext GetForDirectory(string directoryPath)
        {
            return s_dependencyLoadContexts.GetOrAdd(directoryPath, (path) => new DependencyAssemblyLoadContext(path));
        }

        private readonly string _dependencyDirPath;

        public DependencyAssemblyLoadContext(string dependencyDirPath)
            : base(nameof(DependencyAssemblyLoadContext))
        {
            _dependencyDirPath = dependencyDirPath;
        }

        protected override Assembly Load(AssemblyName assemblyName)
        {
            string assemblyFileName = $"{assemblyName.Name}.dll";

            // Make sure we allow other common PowerShell dependencies to be loaded by PowerShell
            // But specifically exclude Microsoft.ApplicationInsightssince we want to use a different version here
            if (!assemblyName.Name.Equals("Microsoft.ApplicationInsights", StringComparison.OrdinalIgnoreCase))
            {
                string psHomeAsmPath = Path.Join(s_psHome, assemblyFileName);
                if (File.Exists(psHomeAsmPath))
                {
                    // With this API, returning null means nothing is loaded
                    return null;
                }
            }

            // Now try to load the assembly from the dependency directory
            string dependencyAsmPath = Path.Join(_dependencyDirPath, assemblyFileName);
            if (File.Exists(dependencyAsmPath))
            {
                return LoadFromAssemblyPath(dependencyAsmPath);
            }

            return null;
        }
    }
}