Replace reflection only load context with shared metadataLoadContext for publishing packages. Solution 1.

src/DynamoCoreWpf/DynamoCoreWpf.csproj

@@ -148,6 +148,7 @@
 	<PackageReference Include="SharpDX.Direct3D9" Version="4.2.0" />
 	<PackageReference Include="SharpDX.DXGI" Version="4.2.0" />
 	<PackageReference Include="SharpDX.Mathematics" Version="4.2.0" />
+	<PackageReference Include="System.Reflection.MetadataLoadContext" Version="6.0.0" />
     <Reference Include="Dynamo.Microsoft.Xaml.Behaviors">
       <HintPath>..\..\extern\Microsoft.Xaml.Behaviors\$(TargetFramework)\Dynamo.Microsoft.Xaml.Behaviors.dll</HintPath>
     </Reference> 

src/DynamoCoreWpf/ViewModels/PackageManager/PublishPackageViewModel.cs

@@ -25,6 +25,7 @@
 using String = System.String;
 using NotificationObject = Dynamo.Core.NotificationObject;
 using Prism.Commands;
+using System.Runtime.InteropServices;
 
 namespace Dynamo.PackageManager
 {
@@ -738,6 +739,22 @@ public string CurrentWarningMessage
             }
         }
 
+        private static MetadataLoadContext sharedMetaDataLoadContext = null;
+        /// <summary>
+        /// A shared MetaDataLoadContext that is used for assembly inspection during package publishing.
+        /// This member is shared so the behavior is similar to the ReflectionOnlyLoadContext this is replacing.
+        /// TODO - eventually it would be good to move to separate publish load contexts that are cleaned up at the appropriate time(?).
+        /// </summary>
+        private static MetadataLoadContext SharedPublishLoadContext
+        {
+            get
+            {
+                sharedMetaDataLoadContext ??= InitSharedPublishLoadContext();
+                return sharedMetaDataLoadContext;
+            }
+        }
+
+
         #endregion
 
         internal PublishPackageViewModel()
@@ -865,11 +882,11 @@ private void ThisPropertyChanged(object sender, PropertyChangedEventArgs e)
             }
         }
 
-        public static PublishPackageViewModel FromLocalPackage(DynamoViewModel dynamoViewModel, Package l)
+        public static PublishPackageViewModel FromLocalPackage(DynamoViewModel dynamoViewModel, Package pkg)
         {
             var defs = new List<CustomNodeDefinition>();
 
-            foreach (var x in l.LoadedCustomNodes)
+            foreach (var x in pkg.LoadedCustomNodes)
             {
                 CustomNodeDefinition def;
                 if (dynamoViewModel.Model.CustomNodeManager.TryGetFunctionDefinition(
@@ -881,44 +898,43 @@ public static PublishPackageViewModel FromLocalPackage(DynamoViewModel dynamoVie
                 }
             }
 
-            var vm = new PublishPackageViewModel(dynamoViewModel)
+            var pkgViewModel = new PublishPackageViewModel(dynamoViewModel)
             {
-                Group = l.Group,
-                Description = l.Description,
-                Keywords = l.Keywords != null ? String.Join(" ", l.Keywords) : "",
+                Group = pkg.Group,
+                Description = pkg.Description,
+                Keywords = pkg.Keywords != null ? String.Join(" ", pkg.Keywords) : "",
                 CustomNodeDefinitions = defs,
-                Name = l.Name,
-                RepositoryUrl = l.RepositoryUrl ?? "",
-                SiteUrl = l.SiteUrl ?? "",
-                Package = l,
-                License = l.License,
-                SelectedHosts = l.HostDependencies as List<string>,
-                CopyrightHolder = l.CopyrightHolder,
-                CopyrightYear = l.CopyrightYear
+                Name = pkg.Name,
+                RepositoryUrl = pkg.RepositoryUrl ?? "",
+                SiteUrl = pkg.SiteUrl ?? "",
+                Package = pkg,
+                License = pkg.License,
+                SelectedHosts = pkg.HostDependencies as List<string>,
+                CopyrightHolder = pkg.CopyrightHolder,
+                CopyrightYear = pkg.CopyrightYear
             };
 
             // add additional files
-            l.EnumerateAdditionalFiles();
-            foreach (var file in l.AdditionalFiles)
+            pkg.EnumerateAdditionalFiles();
+            foreach (var file in pkg.AdditionalFiles)
             {
-                vm.AdditionalFiles.Add(file.Model.FullName);
+                pkgViewModel.AdditionalFiles.Add(file.Model.FullName);
             }
 
-            var nodeLibraryNames = l.Header.node_libraries;
+            var nodeLibraryNames = pkg.Header.node_libraries;
 
             var assembliesLoadedTwice = new List<string>();
-            // load assemblies into reflection only context
-            foreach (var file in l.EnumerateAssemblyFilesInBinDirectory())
+            foreach (var file in pkg.EnumerateAssemblyFilesInPackage())
             {
                 Assembly assem;
-                var result = PackageLoader.TryReflectionOnlyLoadFrom(file, out assem);
+                var result = PackageLoader.TryMetaDataContextLoad(file, SharedPublishLoadContext, out assem);
 
                 switch (result)
                 {
                     case AssemblyLoadingState.Success:
                         {
                             var isNodeLibrary = nodeLibraryNames == null || nodeLibraryNames.Contains(assem.FullName);
-                            vm.Assemblies.Add(new PackageAssembly()
+                            pkgViewModel.Assemblies.Add(new PackageAssembly()
                             {
                                 IsNodeLibrary = isNodeLibrary,
                                 Assembly = assem
@@ -928,7 +944,7 @@ public static PublishPackageViewModel FromLocalPackage(DynamoViewModel dynamoVie
                     case AssemblyLoadingState.NotManagedAssembly:
                         {
                             // if it's not a .NET assembly, we load it as an additional file
-                            vm.AdditionalFiles.Add(file);
+                            pkgViewModel.AdditionalFiles.Add(file);
                             break;
                         }
                     case AssemblyLoadingState.AlreadyLoaded:
@@ -940,24 +956,24 @@ public static PublishPackageViewModel FromLocalPackage(DynamoViewModel dynamoVie
             }
 
             //after dependencies are loaded refresh package contents
-            vm.RefreshPackageContents();
-            vm.UpdateDependencies();
+            pkgViewModel.RefreshPackageContents();
+            pkgViewModel.UpdateDependencies();
 
             if (assembliesLoadedTwice.Any())
             {
-                vm.UploadState = PackageUploadHandle.State.Error;
-                vm.ErrorString = Resources.OneAssemblyWasLoadedSeveralTimesErrorMessage + string.Join("\n", assembliesLoadedTwice);
+                pkgViewModel.UploadState = PackageUploadHandle.State.Error;
+                pkgViewModel.ErrorString = Resources.OneAssemblyWasLoadedSeveralTimesErrorMessage + string.Join("\n", assembliesLoadedTwice);
             }
 
-            if (l.VersionName == null) return vm;
+            if (pkg.VersionName == null) return pkgViewModel;
 
-            var parts = l.VersionName.Split('.');
-            if (parts.Count() != 3) return vm;
+            var parts = pkg.VersionName.Split('.');
+            if (parts.Count() != 3) return pkgViewModel;
 
-            vm.MajorVersion = parts[0];
-            vm.MinorVersion = parts[1];
-            vm.BuildVersion = parts[2];
-            return vm;
+            pkgViewModel.MajorVersion = parts[0];
+            pkgViewModel.MinorVersion = parts[1];
+            pkgViewModel.BuildVersion = parts[2];
+            return pkgViewModel;
 
         }
 
@@ -1868,5 +1884,14 @@ internal void EnableInvalidNameWarningState(string warningMessage)
             CurrentWarningMessage = warningMessage;
             IsWarningEnabled = true;
         }
+
+        private static MetadataLoadContext InitSharedPublishLoadContext()
+        {
+            // Retrieve the location of the assembly and the referenced assemblies used by the domain
+            var runtimeAssemblies = Directory.GetFiles(RuntimeEnvironment.GetRuntimeDirectory(), "*.dll");
+            // Create PathAssemblyResolver that can resolve assemblies using the created list.
+            var resolver = new PathAssemblyResolver(runtimeAssemblies);
+             return new MetadataLoadContext(resolver);
+        }
     }
 }

src/DynamoPackages/DynamoPackages.csproj

@@ -33,6 +33,7 @@
     <PackageReference Include="Greg" Version="3.0.0.2955" />
     <PackageReference Include="Newtonsoft.Json" Version="13.0.1" />
     <PackageReference Include="RestSharp" Version="109.0.1" />
+    <PackageReference Include="System.Reflection.MetadataLoadContext" Version="6.0.0" />
   </ItemGroup>
   <ItemGroup>
     <Compile Update="Properties\Resources.Designer.cs">

src/DynamoPackages/Package.cs

@@ -327,7 +327,8 @@ public void EnumerateAdditionalFiles()
             AdditionalFiles.AddRange(nonDyfDllFiles);
         }
 
-        public IEnumerable<string> EnumerateAssemblyFilesInBinDirectory()
+        //TODO can we make this internal?
+        public IEnumerable<string> EnumerateAssemblyFilesInPackage()
         {
             if (String.IsNullOrEmpty(RootDirectory) || !Directory.Exists(RootDirectory)) 
                 return new List<string>();

src/DynamoPackages/PackageLoader.cs

@@ -743,28 +743,38 @@ private void CheckPackageNodeLibraryCertificates(string packageDirectoryPath, Pa
         }
 
         /// <summary>
-        ///     Attempt to load a managed assembly in to ReflectionOnlyLoadFrom context. 
+        ///     Attempt to load a managed assembly in to MetaDataLoad context. 
         /// </summary>
         /// <param name="filename">The filename of a DLL</param>
+        /// <param name="mlc">The MetaDataLoadContext to load the package assemblies into for inspection.</param>
         /// <param name="assem">out Assembly - the passed value does not matter and will only be set if loading succeeds</param>
         /// <returns>Returns Success if success, NotManagedAssembly if BadImageFormatException, AlreadyLoaded if FileLoadException</returns>
-        internal static AssemblyLoadingState TryReflectionOnlyLoadFrom(string filename, out Assembly assem)
+        internal static AssemblyLoadingState TryMetaDataContextLoad(string filename,MetadataLoadContext mlc, out Assembly assem)
         {
-            try
-            {
-                assem = Assembly.ReflectionOnlyLoadFrom(filename);
-                return AssemblyLoadingState.Success;
-            }
-            catch (BadImageFormatException)
-            {
-                assem = null;
-                return AssemblyLoadingState.NotManagedAssembly;
-            }
-            catch (FileLoadException)
-            {
-                assem = null;
-                return AssemblyLoadingState.AlreadyLoaded;
-            }
+                try
+                {
+                    var mlcAssemblies = mlc.GetAssemblies();
+                    assem = mlc.LoadFromAssemblyPath(filename);
+                    var mlcAssemblies2 = mlc.GetAssemblies();
+                    //if loading the assembly did not actually add a new assembly to the MLC
+                    //then we've loaded it already, and our current behavior is to
+                    //disable publish when a package contains the same assembly twice.
+                    if (mlcAssemblies2.Count() == mlcAssemblies.Count())
+                    {
+                        throw new FileLoadException(filename);
+                    }
+                    return AssemblyLoadingState.Success;
+                }
+                catch (BadImageFormatException)
+                {
+                    assem = null;
+                    return AssemblyLoadingState.NotManagedAssembly;
+                }
+                catch (FileLoadException)
+                {
+                    assem = null;
+                    return AssemblyLoadingState.AlreadyLoaded;
+                }
         }
 
         /// <summary>

test/DynamoCoreWpfTests/PackagePathTests.cs

@@ -1,4 +1,4 @@
-
+
 using System.IO;
 using System.Linq;
 using System.Reflection;
@@ -233,17 +233,17 @@ public void InstalledPackagesContainsCorrectNumberOfPackages()
             vm.packageLoader.PackagesLoaded += pkgsLoadedDelegate;
 
             vm.packageLoader.LoadAll(vm.loadPackageParams);
-            Assert.AreEqual(19, vm.packageLoader.LocalPackages.Count());
+            Assert.AreEqual(20, vm.packageLoader.LocalPackages.Count());
             Assert.AreEqual(true, packagesLoaded);
 
             var installedPackagesViewModel = new InstalledPackagesViewModel(ViewModel, vm.packageLoader);
-            Assert.AreEqual(19, installedPackagesViewModel.LocalPackages.Count);
+            Assert.AreEqual(20, installedPackagesViewModel.LocalPackages.Count);
 
             var installedPackagesView = new Dynamo.Wpf.Controls.InstalledPackagesControl();
             installedPackagesView.DataContext = installedPackagesViewModel;
             DispatcherUtil.DoEvents();
 
-            Assert.AreEqual(19, installedPackagesView.SearchResultsListBox.Items.Count);
+            Assert.AreEqual(20, installedPackagesView.SearchResultsListBox.Items.Count);
             Assert.AreEqual(2, installedPackagesView.Filters.Items.Count);
 
             vm.packageLoader.PackagesLoaded -= libraryLoader.LoadPackages;
@@ -267,7 +267,7 @@ public void RemoveAddPackagePathChangesInstalledPackageState()
             // Load packages in package path.
             vm.packageLoader.LoadAll(vm.loadPackageParams);
 
-            Assert.AreEqual(19, vm.packageLoader.LocalPackages.Count());
+            Assert.AreEqual(20, vm.packageLoader.LocalPackages.Count());
             // Remove package path.
             vm.DeletePathCommand.Execute(0);
 
@@ -323,7 +323,7 @@ public void EnableCustomPackagePathsLoadsPackagesOnClosingPreferences()
             vm.SaveSettingCommand.Execute(null);
 
             // packages are expected to load from 'PackagesDirectory' above when toggle is turned off
-            Assert.AreEqual(19, vm.packageLoader.LocalPackages.Count());
+            Assert.AreEqual(20, vm.packageLoader.LocalPackages.Count());
 
             vm.packageLoader.PackagesLoaded -= libraryLoader.LoadPackages;
             vm.packageLoader.RequestLoadNodeLibrary -= libraryLoader.LoadLibraryAndSuppressZTSearchImport;

test/DynamoCoreWpfTests/PublishPackageViewModelTests.cs

@@ -2,6 +2,7 @@
 using System.Collections.Generic;
 using System.IO;
 using System.Linq;
+using System.Reflection;
 using Dynamo;
 using Dynamo.Graph.Nodes.CustomNodes;
 using Dynamo.Graph.Workspaces;
@@ -17,7 +18,7 @@ namespace DynamoCoreWpfTests
     public class PublishPackageViewModelTests: DynamoViewModelUnitTest
     {
 
-        [Test, Category("Failure")]
+        [Test]
         public void AddingDyfRaisesCanExecuteChangeOnDelegateCommand()
         {
 
@@ -99,7 +100,34 @@ public void CanPublishLateInitializedJsonCustomNode()
         }
 
 
-        [Test, Category("Failure")]
+        [Test]
+        public void NewPackageDoesNotThrow_NativeBinaryIsAddedAsAdditionalFile_NotBinary()
+        {
+            string packagesDirectory = Path.Combine(TestDirectory, "pkgs");
+
+            var pathManager = new Mock<Dynamo.Interfaces.IPathManager>();
+            pathManager.SetupGet(x => x.PackagesDirectories).Returns(() => new List<string> { packagesDirectory });
+
+            var loader = new PackageLoader(pathManager.Object);
+            loader.LoadAll(new LoadPackageParams
+            {
+                Preferences = ViewModel.Model.PreferenceSettings
+            });
+
+            PublishPackageViewModel vm = null;
+            var package = loader.LocalPackages.FirstOrDefault(x => x.Name == "package with native assembly");
+            Assert.DoesNotThrow(() =>
+            {
+                vm = PublishPackageViewModel.FromLocalPackage(ViewModel, package);
+            });
+
+            Assert.AreEqual(1, vm.AdditionalFiles.Count);
+            Assert.AreEqual(0, vm.Assemblies.Count);
+
+            Assert.AreEqual(PackageUploadHandle.State.Ready, vm.UploadState);
+        }
+
+        [Test]
         public void NewPackageVersionUpload_DoesNotThrowExceptionWhenDLLIsLoadedSeveralTimes()
         {
             string packagesDirectory = Path.Combine(TestDirectory, "pkgs");
@@ -123,7 +151,7 @@ public void NewPackageVersionUpload_DoesNotThrowExceptionWhenDLLIsLoadedSeveralT
             Assert.AreEqual(PackageUploadHandle.State.Error, vm.UploadState);
         }
 
-        [Test, Category("Failure")]
+        [Test]
         public void NewPackageVersionUpload_CanAddAndRemoveFiles()
         {
             string packagesDirectory = Path.Combine(TestDirectory, "pkgs");