Remove System.Runtime.Loader dependency to enable net461 support. Use IApplicationLifetime instead of AssemblyLoadContext.Default.Unloading.

src/Microsoft.AspNetCore.NodeServices/Configuration/NodeServicesOptions.cs

@@ -1,5 +1,6 @@
 using System;
 using System.Collections.Generic;
+using System.Threading;
 using Microsoft.AspNetCore.NodeServices.HostingModels;
 using Microsoft.Extensions.Logging;
 using Microsoft.Extensions.DependencyInjection;
@@ -42,6 +43,12 @@ namespace Microsoft.AspNetCore.NodeServices
                 EnvironmentVariables["NODE_ENV"] = hostEnv.IsDevelopment() ? "development" : "production"; // De-facto standard values for Node
             }
 
+            var applicationLifetime = serviceProvider.GetService<IApplicationLifetime>();
+            if (applicationLifetime != null)
+            {
+                ApplicationStoppingToken = applicationLifetime.ApplicationStopping;
+            }
+
             // If the DI system gives us a logger, use it. Otherwise, set up a default one.
             var loggerFactory = serviceProvider.GetService<ILoggerFactory>();
             NodeInstanceOutputLogger = loggerFactory != null
@@ -93,5 +100,10 @@ namespace Microsoft.AspNetCore.NodeServices
         /// Specifies the maximum duration, in milliseconds, that your .NET code should wait for Node.js RPC calls to return.
         /// </summary>
         public int InvocationTimeoutMilliseconds { get; set; }
+
+        /// <summary>
+        /// A token that indicates when the host application is stopping.
+        /// </summary>
+        public CancellationToken ApplicationStoppingToken { get; set; }
     }
 }

src/Microsoft.AspNetCore.NodeServices/HostingModels/HttpNodeInstance.cs

@@ -42,6 +42,7 @@ namespace Microsoft.AspNetCore.NodeServices.HostingModels
                 options.ProjectPath,
                 options.WatchFileExtensions,
                 MakeCommandLineOptions(port),
+                options.ApplicationStoppingToken,
                 options.NodeInstanceOutputLogger,
                 options.EnvironmentVariables,
                 options.InvocationTimeoutMilliseconds,

src/Microsoft.AspNetCore.NodeServices/HostingModels/OutOfProcessNodeInstance.cs

@@ -45,6 +45,7 @@ namespace Microsoft.AspNetCore.NodeServices.HostingModels
         /// <param name="projectPath">The root path of the current project. This is used when resolving Node.js module paths relative to the project root.</param>
         /// <param name="watchFileExtensions">The filename extensions that should be watched within the project root. The Node instance will automatically shut itself down if any matching file changes.</param>
         /// <param name="commandLineArguments">Additional command-line arguments to be passed to the Node.js instance.</param>
+        /// <param name="applicationStoppingToken">A token that indicates when the host application is stopping.</param>
         /// <param name="nodeOutputLogger">The <see cref="ILogger"/> to which the Node.js instance's stdout/stderr (and other log information) should be written.</param>
         /// <param name="environmentVars">Environment variables to be set on the Node.js process.</param>
         /// <param name="invocationTimeoutMilliseconds">The maximum duration, in milliseconds, to wait for RPC calls to complete.</param>
@@ -55,6 +56,7 @@ namespace Microsoft.AspNetCore.NodeServices.HostingModels
             string projectPath,
             string[] watchFileExtensions,
             string commandLineArguments,
+            CancellationToken applicationStoppingToken,
             ILogger nodeOutputLogger,
             IDictionary<string, string> environmentVars,
             int invocationTimeoutMilliseconds,
@@ -67,7 +69,7 @@ namespace Microsoft.AspNetCore.NodeServices.HostingModels
             }
 
             OutputLogger = nodeOutputLogger;
-            _entryPointScript = new StringAsTempFile(entryPointScript);
+            _entryPointScript = new StringAsTempFile(entryPointScript, applicationStoppingToken);
             _invocationTimeoutMilliseconds = invocationTimeoutMilliseconds;
             _launchWithDebugging = launchWithDebugging;
 

src/Microsoft.AspNetCore.NodeServices/Microsoft.AspNetCore.NodeServices.csproj

@@ -18,7 +18,6 @@
     <PackageReference Include="Microsoft.AspNetCore.Hosting.Abstractions" Version="$(AspNetCoreVersion)" />
     <PackageReference Include="Microsoft.Extensions.Logging.Console" Version="$(AspNetCoreVersion)" />
     <PackageReference Include="Newtonsoft.Json" Version="$(JsonNetVersion)" />
-    <PackageReference Include="System.Runtime.Loader" Version="$(CoreFxVersion)" />
   </ItemGroup>
 
   <Target Name="PrepublishScript" BeforeTargets="PrepareForPublish" Condition=" '$(IsCrossTargetingBuild)' != 'true' ">

src/Microsoft.AspNetCore.NodeServices/Util/StringAsTempFile.cs

@@ -1,5 +1,6 @@
 using System;
 using System.IO;
+using System.Threading;
 
 namespace Microsoft.AspNetCore.NodeServices
 {
@@ -11,22 +12,21 @@ namespace Microsoft.AspNetCore.NodeServices
         private bool _disposedValue;
         private bool _hasDeletedTempFile;
         private object _fileDeletionLock = new object();
+        private IDisposable _applicationLifetimeRegistration;
 
         /// <summary>
         /// Create a new instance of <see cref="StringAsTempFile"/>.
         /// </summary>
         /// <param name="content">The contents of the temporary file to be created.</param>
-        public StringAsTempFile(string content)
+        /// <param name="applicationStoppingToken">A token that indicates when the host application is stopping.</param>
+        public StringAsTempFile(string content, CancellationToken applicationStoppingToken)
         {
             FileName = Path.GetTempFileName();
             File.WriteAllText(FileName, content);
 
             // Because .NET finalizers don't reliably run when the process is terminating, also
             // add event handlers for other shutdown scenarios.
-            // Note that this still doesn't capture SIGKILL (at least on macOS) - there doesn't
-            // appear to be a way of doing that. So in that case, the temporary file will be
-            // left behind.
-            System.Runtime.Loader.AssemblyLoadContext.Default.Unloading += HandleAssemblyUnloading;
+            _applicationLifetimeRegistration = applicationStoppingToken.Register(EnsureTempFileDeleted);
         }
 
         /// <summary>
@@ -50,7 +50,7 @@ namespace Microsoft.AspNetCore.NodeServices
                 if (disposing)
                 {
                     // Dispose managed state
-                    System.Runtime.Loader.AssemblyLoadContext.Default.Unloading -= HandleAssemblyUnloading;
+                    _applicationLifetimeRegistration.Dispose();
                 }
 
                 EnsureTempFileDeleted();
@@ -71,11 +71,6 @@ namespace Microsoft.AspNetCore.NodeServices
             }
         }
 
-        private void HandleAssemblyUnloading(System.Runtime.Loader.AssemblyLoadContext context)
-        {
-            EnsureTempFileDeleted();
-        }
-
         /// <summary>
         /// Implements the finalization part of the IDisposable pattern by calling Dispose(false).
         /// </summary>