Abstracting Assembly Resolver

src/Microsoft.TestPlatform.Common/ExtensionFramework/TestPluginCache.cs

@@ -10,16 +10,16 @@ namespace Microsoft.VisualStudio.TestPlatform.Common.ExtensionFramework
     using System.Reflection;
     using System.Text.RegularExpressions;
 
+#if NET46
+    using System.Threading;
+#endif
+
     using Microsoft.VisualStudio.TestPlatform.Common.ExtensionFramework.Utilities;
-    using Microsoft.VisualStudio.TestPlatform.Common.Utilities;
     using Microsoft.VisualStudio.TestPlatform.ObjectModel;
+    using Microsoft.VisualStudio.TestPlatform.PlatformAbstractions;
+    using Microsoft.VisualStudio.TestPlatform.PlatformAbstractions.Interfaces;
     using Microsoft.VisualStudio.TestPlatform.Utilities.Helpers;
     using Microsoft.VisualStudio.TestPlatform.Utilities.Helpers.Interfaces;
-#if NET46
-    using System.Threading;
-#else
-    using System.Runtime.Loader;
-#endif
 
     /// <summary>
     /// The test plugin cache.
@@ -29,7 +29,6 @@ public class TestPluginCache
     {
         #region Private Members
 
-        private readonly Dictionary<string, Assembly> resolvedAssemblies;
         private readonly IFileHelper fileHelper;
 
         /// <summary>
@@ -45,7 +44,7 @@ public class TestPluginCache
         /// <summary>
         /// Assembly resolver used to resolve the additional extensions
         /// </summary>
-        private AssemblyResolver assemblyResolver;
+        private IAssemblyResolver assemblyResolver;
 
         /// <summary>
         /// Lock for extensions update
@@ -68,7 +67,6 @@ public class TestPluginCache
         /// </param>
         protected TestPluginCache(IFileHelper fileHelper)
         {
-            this.resolvedAssemblies = new Dictionary<string, Assembly>();
             this.pathToExtensions = null;
             this.loadOnlyWellKnownExtensions = false;
             this.lockForExtensionsUpdate = new object();
@@ -158,11 +156,8 @@ public bool LoadOnlyWellKnownExtensions
             // and that succeeds.
             // Because of this assembly failure, below domain.CreateInstanceAndUnwrap() call fails with error
             // "Unable to cast transparent proxy to type 'Microsoft.VisualStudio.TestPlatform.Core.TestPluginsFramework.TestPluginDiscoverer"
-#if NET46
-            AppDomain.CurrentDomain.AssemblyResolve += new ResolveEventHandler(CurrentDomainAssemblyResolve);
-#else
-            AssemblyLoadContext.Default.Resolving += this.CurrentDomainAssemblyResolve;
-#endif
+            this.assemblyResolver.SetCurrentDomainAssemblyResolve();
+
             try
             {
                 EqtTrace.Verbose("TestPluginCache: Discovering the extensions using extension path.");
@@ -218,17 +213,7 @@ public bool LoadOnlyWellKnownExtensions
             }
             finally
             {
-#if NET46
-                AppDomain.CurrentDomain.AssemblyResolve -= new ResolveEventHandler(CurrentDomainAssemblyResolve);
-#else
-                AssemblyLoadContext.Default.Resolving -= this.CurrentDomainAssemblyResolve;
-#endif
-
-                // clear the assemblies
-                lock (this.resolvedAssemblies)
-                {
-                    this.resolvedAssemblies?.Clear();
-                }
+                this.assemblyResolver.RemoveCurrentDomainAssemblyResolve();
             }
 
             return pluginInfos;
@@ -274,7 +259,6 @@ public void UpdateExtensions(IEnumerable<string> additionalExtensionsPath, bool
                 // directory. The path to nuget directory is automatically setup for CLR to resolve.
                 // Test platform tries to load every extension by assembly name. If it is not resolved, we don't
                 // an error.
-
                 if (this.pathToExtensions != null)
                 {
                     extensions.AddRange(this.pathToExtensions);
@@ -316,6 +300,7 @@ internal IEnumerable<string> DefaultExtensionPaths
             {
                 return this.defaultExtensionPaths;
             }
+
             set
             {
                 if (value != null)
@@ -501,55 +486,14 @@ private void SetupAssemblyResolver(string extensionAssembly)
             // Add assembly resolver which can resolve the extensions from the specified directory.
             if (this.assemblyResolver == null)
             {
-                this.assemblyResolver = new AssemblyResolver(resolutionPaths);
+                this.assemblyResolver = new AssemblyResolver(resolutionPaths, EqtTrace.PlatformTrace);
             }
             else
             {
                 this.assemblyResolver.AddSearchDirectories(resolutionPaths);
             }
         }
 
-#if NET46
-        private Assembly CurrentDomainAssemblyResolve(object sender, ResolveEventArgs args)
-#else
-        private Assembly CurrentDomainAssemblyResolve(AssemblyLoadContext loadContext, AssemblyName args)
-#endif
-        {
-            var assemblyName = new AssemblyName(args.Name);
-
-            Assembly assembly = null;
-            lock (this.resolvedAssemblies)
-            {
-                try
-                {
-                    EqtTrace.Verbose("CurrentDomain_AssemblyResolve: Resolving assembly '{0}'.", args.Name);
-
-                    if (this.resolvedAssemblies.TryGetValue(args.Name, out assembly))
-                    {
-                        return assembly;
-                    }
-
-                    // Put it in the resolved assembly so that if below Assembly.Load call
-                    // triggers another assembly resolution, then we dont end up in stack overflow
-                    this.resolvedAssemblies[args.Name] = null;
-
-                    assembly = Assembly.Load(assemblyName);
-
-                    // Replace the value with the loaded assembly
-                    this.resolvedAssemblies[args.Name] = assembly;
-
-                    return assembly;
-                }
-                finally
-                {
-                    if (null == assembly)
-                    {
-                        EqtTrace.Verbose("CurrentDomainAssemblyResolve: Failed to resolve assembly '{0}'.", args.Name);
-                    }
-                }
-            }
-        }
-
         /// <summary>
         /// Log the extensions
         /// </summary>

src/Microsoft.TestPlatform.Common/ExtensionFramework/TestPluginDiscoverer.cs

@@ -13,9 +13,6 @@ namespace Microsoft.VisualStudio.TestPlatform.Common.ExtensionFramework
 
     using Microsoft.VisualStudio.TestPlatform.Common.ExtensionFramework.Utilities;
     using Microsoft.VisualStudio.TestPlatform.ObjectModel;
-#if !NET46
-    using System.Runtime.Loader;
-#endif
 
     /// <summary>
     /// Discovers test extensions in a directory.
@@ -133,11 +130,11 @@ internal class TestPluginDiscoverer
             Debug.Assert(pluginInfos != null, "null pluginInfos");
 
             // TODO: Do not see why loadOnlyWellKnowExtensions is still needed.
-            //AssemblyName executingAssemblyName = null;
-            //if (loadOnlyWellKnownExtensions)
-            //{
+            // AssemblyName executingAssemblyName = null;
+            // if (loadOnlyWellKnownExtensions)
+            // {
             //    executingAssemblyName = new AssemblyName(typeof(TestPluginDiscoverer).GetTypeInfo().Assembly.FullName);
-            //}
+            // }
 
             // Scan each of the files for data extensions.
             foreach (var file in files)
@@ -153,15 +150,15 @@ internal class TestPluginDiscoverer
                     }
 
                     // Check whether this assembly is known or not.
-                    //if (loadOnlyWellKnownExtensions && assembly != null)
-                    //{
+                    // if (loadOnlyWellKnownExtensions && assembly != null)
+                    // {
                     //    var extensionAssemblyName = new AssemblyName(assembly.FullName);
                     //    if (!AssemblyUtilities.PublicKeyTokenMatches(extensionAssemblyName, executingAssemblyName))
                     //    {
                     //        EqtTrace.Warning("TestPluginDiscoverer: Ignoring extensions in assembly {0} as it is not a known assembly.", assembly.FullName);
                     //        continue;
                     //    }
-                    //}
+                    // }
                 }
                 catch (Exception e)
                 {

src/Microsoft.TestPlatform.CoreUtilities/Tracing/EqtTrace.cs

@@ -64,6 +64,14 @@ public static PlatformTraceLevel TraceLevel
         }
 #endif
 
+        public static IPlatformEqtTrace PlatformTrace
+        {
+            get
+            {
+                return traceImpl;
+            }
+        }
+
         public static string LogFile
         {
             get
@@ -126,18 +134,23 @@ public static bool IsWarningEnabled
         /// Initializes the verbose tracing with custom log file
         /// And overrides if any trace is set before
         /// </summary>
-        /// <param name="customLogFile">A custom log file for trace messages.</param>
+        /// <param name="customLogFile">
+        /// A custom log file for trace messages.
+        /// </param>
+        /// <returns>
+        /// The <see cref="bool"/>.
+        /// </returns>
         public static bool InitializeVerboseTrace(string customLogFile)
         {
-            if(!traceImpl.InitializeVerboseTrace(customLogFile))
+            if (!traceImpl.InitializeVerboseTrace(customLogFile))
             {
                 ErrorOnInitialization = PlatformEqtTrace.ErrorOnInitialization;
                 return false;
             }
+
             return true;
         }
 
-
         /// <summary>
         /// Prints an error message and prompts with a Debug dialog
         /// </summary>

src/Microsoft.TestPlatform.PlatformAbstractions/Interfaces/System/IAssemblyResolver.cs

@@ -0,0 +1,30 @@
+// Copyright (c) Microsoft Corporation. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+
+namespace Microsoft.VisualStudio.TestPlatform.PlatformAbstractions.Interfaces
+{
+    using System;
+    using System.Collections.Generic;
+
+    /// <summary>
+    /// The AssemblyResolver interface.
+    /// </summary>
+    public interface IAssemblyResolver : IDisposable
+    {
+        /// <summary>
+        /// Sets up the Assembly resovler for current Appdomain
+        /// </summary>
+        void SetCurrentDomainAssemblyResolve();
+
+        /// <summary>
+        /// Removes the Assembly resolver from current Appdomain
+        /// </summary>
+        void RemoveCurrentDomainAssemblyResolve();
+
+        /// <summary>
+        /// Add the probing directories look for in case of Aseembly Resolve Event
+        /// </summary>
+        /// <param name="directories"></param>
+        void AddSearchDirectories(IEnumerable<string> directories);
+    }
+}

src/Microsoft.TestPlatform.PlatformAbstractions/Interfaces/Tracing/IEqtTrace.cs → src/Microsoft.TestPlatform.PlatformAbstractions/Interfaces/Tracing/IPlatformEqtTrace.cs

@@ -1,34 +1,12 @@
-namespace Microsoft.VisualStudio.TestPlatform.ObjectModel
-{
-    //
-    // Summary:
-    //     Specifies what messages to output for the System.Diagnostics.Debug, System.Diagnostics.Trace
-    //     and System.Diagnostics.TraceSwitch classes.
-    public enum PlatformTraceLevel
-    {
-        //
-        // Summary:
-        //     Output no tracing and debugging messages.
-        Off = 0,
-        //
-        // Summary:
-        //     Output error-handling messages.
-        Error = 1,
-        //
-        // Summary:
-        //     Output warnings and error-handling messages.
-        Warning = 2,
-        //
-        // Summary:
-        //     Output informational messages, warnings, and error-handling messages.
-        Info = 3,
-        //
-        // Summary:
-        //     Output all debugging and tracing messages.
-        Verbose = 4
-    }
-
+// Copyright (c) Microsoft Corporation. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
 
+namespace Microsoft.VisualStudio.TestPlatform.ObjectModel
+{
+    /// <summary>
+    /// Specifies what messages to output for the System.Diagnostics.Debug, System.Diagnostics.Trace
+    /// and System.Diagnostics.TraceSwitch classes.
+    /// </summary>
     public partial interface IPlatformEqtTrace
     {
         /// <summary>
@@ -44,7 +22,12 @@ public partial interface IPlatformEqtTrace
         /// Initializes the verbose tracing with custom log file
         /// And overrides if any trace is set before
         /// </summary>
-        /// <param name="customLogFile">A custom log file for trace messages.</param>
+        /// <param name="customLogFile">
+        /// A custom log file for trace messages.
+        /// </param>
+        /// <returns>
+        /// The <see cref="bool"/>.
+        /// </returns>
         bool InitializeVerboseTrace(string customLogFile);
 
         /// <summary>
@@ -63,12 +46,17 @@ public partial interface IPlatformEqtTrace
         /// <summary>
         /// Sets platfrom specific trace value for tracing verbosity.
         /// </summary>
-        /// <param name="traceLevel">PlatformTraceLevel.</param>
+        /// <param name="value">
+        /// The value.
+        /// </param>
         void SetTraceLevel(PlatformTraceLevel value);
 
         /// <summary>
         /// Gets platfrom specific trace value for tracing verbosity.
         /// </summary>
+        /// <returns>
+        /// The <see cref="PlatformTraceLevel"/>.
+        /// </returns>
         PlatformTraceLevel GetTraceLevel();
     }
 }

src/Microsoft.TestPlatform.PlatformAbstractions/Interfaces/Tracing/PlatformTraceLevel.cs

@@ -0,0 +1,33 @@
+// Copyright (c) Microsoft Corporation. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+
+namespace Microsoft.VisualStudio.TestPlatform.ObjectModel
+{
+    public enum PlatformTraceLevel
+    {
+        /// <summary>
+        /// Output no tracing and debugging messages..
+        /// </summary>
+        Off = 0,
+
+        /// <summary>
+        /// Output error-handling messages.
+        /// </summary>
+        Error = 1,
+
+        /// <summary>
+        /// Output warnings and error-handling messages.
+        /// </summary>
+        Warning = 2,
+
+        /// <summary>
+        /// Output informational messages, warnings, and error-handling messages..
+        /// </summary>
+        Info = 3,
+
+        /// <summary>
+        /// Output all debugging and tracing messages..
+        /// </summary>
+        Verbose = 4
+    }
+}