Specify target framework in generated assembly loader script (#394)

Author: jasongin

docs/reference/msbuild-props.md

@@ -9,6 +9,7 @@ The following properties can be used to customize the build processes for genera
 | `NodeApiTypeDefinitionsFileName`              | Name of the type-definitions file generated for a project. Defaults to `$(TargetName).d.ts`. |
 | `NodeApiTypeDefinitionsEnableWarnings`        | Set to `true` to enable warnings when [generating type definitions](../features/type-definitions). The warnings are suppressed by default because they can be verbose when referencing system or external assemblies.
 | `NodeApiJSModuleType`                         | Set to either `commonjs` or `esm` to specify the module system used by the generated type definitions. If unspecified, the module type is detected automatically from `package.json`, which is usually correct. |
+| `NodeApiTargetFramework`                      | Target framework moniker that will be loaded at runtime for the Node API .NET host. Default is the project's `$(TargetFramework)`.
 | `NodeApiSystemReferenceAssembly`              | Item-list of assembly names (not file paths) to be included in typedefs generator. The `System`, `System.Runtime`, and `System.Console` assemblies are included by default. Add system assembly names to the item-list to generate type definitions for them. System assemblies are provided by the installed .NET SDK. |
 | `PublishNodeModule`                           | Set to `true` to produce a Native AOT `.node` binary and `.js` module-loader script when building the `Publish` target. The files will be placed in the directory indicated by the `PublishDir` variable. See [Develop a Node.js addon module with .NET Native AOT](../scenarios/js-aot-module). |
 | `PublishMultiPlatformNodeModule`              | If `true`, the published `.node` binary file will be placed in a sub-directory according to the targeted [`RuntimeIdentifier`](https://learn.microsoft.com/en-us/dotnet/core/project-sdk/msbuild-props#runtimeidentifier), for example `win-x64`. Then the publish process may be run spearately for multiple runtime-identifiers, and the module-loader script chooses the approrpriate one at runtime. |

src/NodeApi.Generator/NodeApi.Generator.targets

@@ -20,7 +20,9 @@
     <NodeApiJSModuleType Condition=" '$(NodeApiJSModuleType)' == '' AND Exists('$(NodeApiPackageJson)') ">&quot;$(NodeApiPackageJson)&quot;</NodeApiJSModuleType>
     <NodeApiJSModuleType Condition=" '$(NodeApiJSModuleType)' == '' ">commonjs,esm</NodeApiJSModuleType>
 
-    <NodeApiTypeDefinitionsGeneratorOptions>--module $(NodeApiJSModuleType) --framework $(TargetFramework) $(NodeApiTypedefsGeneratorOptions)</NodeApiTypeDefinitionsGeneratorOptions>
+    <NodeApiTargetFramework Condition=" '$(NodeApiTargetFramework)' == '' ">$(TargetFramework)</NodeApiTargetFramework>
+
+    <NodeApiTypeDefinitionsGeneratorOptions>--module $(NodeApiJSModuleType) --framework $(NodeApiTargetFramework) $(NodeApiTypedefsGeneratorOptions)</NodeApiTypeDefinitionsGeneratorOptions>
   </PropertyGroup>
 
   <!--

src/NodeApi.Generator/Program.cs

@@ -32,6 +32,7 @@ public static class Program
 {
     private const char PathSeparator = ';';
 
+    private static string? s_targetFramework;
     private static readonly List<string> s_assemblyPaths = new();
     private static readonly List<string> s_referenceAssemblyDirectories = new();
     private static readonly List<string> s_referenceAssemblyPaths = new();
@@ -49,7 +50,7 @@ public static int Main(string[] args)
             Console.WriteLine("""
                 Usage: node-api-dotnet-generator [options...]
                   -a --asssembly  Path to input assembly (required)
-                  -f --framework  Target framework of system assemblies (optional)
+                  -f --framework  .NET target framework moniker (optional)
                   -p --pack       Targeting pack (optional, multiple)
                   -r --reference  Path to reference assembly (optional, multiple)
                   -t --typedefs   Path to output type definitions file (required)
@@ -105,6 +106,7 @@ public static int Main(string[] args)
                 s_referenceAssemblyDirectories,
                 s_typeDefinitionsPaths[i],
                 modulePaths,
+                s_targetFramework,
                 isSystemAssembly: s_systemAssemblyIndexes.Contains(i),
                 s_suppressWarnings);
         }
@@ -119,7 +121,6 @@ private static bool ParseArgs(string[] args)
             return false;
         }
 
-        string? targetFramework = null;
         List<string> targetingPacks = new();
 
         for (int i = 0; i < args.Length; i++)
@@ -149,7 +150,7 @@ void AddItems(List<string> list, string items)
 
                 case "-f":
                 case "--framework":
-                    targetFramework = args[++i];
+                    s_targetFramework = args[++i];
                     break;
 
                 case "-p":
@@ -220,7 +221,7 @@ void AddItems(List<string> list, string items)
             }
         }
 
-        ResolveSystemAssemblies(targetFramework, targetingPacks);
+        ResolveSystemAssemblies(targetingPacks);
 
         bool HasAssemblyExtension(string fileName) =>
             fileName.EndsWith(".dll", StringComparison.OrdinalIgnoreCase) ||
@@ -396,20 +397,19 @@ private static IEnumerable<string> SplitWithQuotes(string line)
     }
 
     private static void ResolveSystemAssemblies(
-        string? targetFramework,
         List<string> targetingPacks)
     {
-        if (targetFramework == null)
+        if (s_targetFramework == null)
         {
-            targetFramework = GetCurrentFrameworkTarget();
+            s_targetFramework = GetCurrentFrameworkTarget();
         }
-        else if (targetFramework.Contains('-'))
+        else if (s_targetFramework.Contains('-'))
         {
             // Strip off a platform suffix from a target framework like "net6.0-windows".
-            targetFramework = targetFramework.Substring(0, targetFramework.IndexOf('-'));
+            s_targetFramework = s_targetFramework.Substring(0, s_targetFramework.IndexOf('-'));
         }
 
-        if (targetFramework.StartsWith("net4"))
+        if (s_targetFramework.StartsWith("net4"))
         {
             if (targetingPacks.Count > 0)
             {
@@ -422,7 +422,7 @@ private static void ResolveSystemAssemblies(
                 "Microsoft",
                 "Framework",
                 ".NETFramework",
-                "v" + string.Join(".", targetFramework.Substring(3).ToArray())); // v4.7.2
+                "v" + string.Join(".", s_targetFramework.Substring(3).ToArray())); // v4.7.2
             if (Directory.Exists(refAssemblyDirectory))
             {
                 s_referenceAssemblyDirectories.Add(refAssemblyDirectory);
@@ -461,7 +461,7 @@ private static void ResolveSystemAssemblies(
                 {
                     string? refAssemblyDirectory = Directory.GetDirectories(targetPackDirectory)
                         .OrderByDescending((d) => Path.GetFileName(d))
-                        .Select((d) => Path.Combine(d, "ref", targetFramework))
+                        .Select((d) => Path.Combine(d, "ref", s_targetFramework))
                         .FirstOrDefault(Directory.Exists);
                     if (refAssemblyDirectory != null)
                     {

src/NodeApi.Generator/TypeDefinitionsGenerator.cs

@@ -46,6 +46,13 @@ public enum ModuleType
         ES,
     }
 
+    private enum AssemblyType
+    {
+        JSModule,
+        ApplicationAssembly,
+        SystemAssembly,
+    }
+
     /// <summary>
     /// JavaScript (not TypeScript) code that is emitted to a `.js` file alongside the `.d.ts`.
     /// Enables application code to load an assembly (containing explicit JS exports) as an ES
@@ -58,7 +65,7 @@ public enum ModuleType
     /// An MSBuild task during the AOT publish process sets the `dotnet` variable to undefined.
     /// </remarks>
     private const string LoadModuleMJS = @"
-import dotnet from 'node-api-dotnet';
+import dotnet from 'node-api-dotnet/$(TargetFramework)';
 import * as path from 'node:path';
 import { fileURLToPath } from 'node:url';
 // @ts-ignore - https://github.com/DefinitelyTyped/DefinitelyTyped/discussions/65252
@@ -92,7 +99,7 @@ function importAotModule(moduleName) {
     /// An MSBuild task during the AOT publish process sets the `dotnet` variable to undefined.
     /// </remarks>
     private const string LoadModuleCJS = @"
-const dotnet = require('node-api-dotnet');
+const dotnet = require('node-api-dotnet/$(TargetFramework)');
 const path = require('node:path');
 // @ts-ignore - https://github.com/DefinitelyTyped/DefinitelyTyped/discussions/65252
 const { dlopen, platform, arch } = require('node:process');
@@ -126,7 +133,7 @@ function importAotModule(moduleName) {
     /// they are equivalent to those predefined values defined for CommonJS modules.
     /// </remarks>
     private const string LoadAssemblyMJS = @"
-import dotnet from 'node-api-dotnet';
+import dotnet from 'node-api-dotnet/$(TargetFramework)';
 import * as path from 'node:path';
 import { fileURLToPath } from 'node:url';
 
@@ -143,7 +150,7 @@ function importAotModule(moduleName) {
     /// the node-api-dotnet module.
     /// </summary>
     private const string LoadAssemblyCJS = @"
-const dotnet = require('node-api-dotnet');
+const dotnet = require('node-api-dotnet/$(TargetFramework)');
 const path = require('node:path');
 
 const assemblyName = path.basename(__filename, __filename.match(/(\.[cm]?js)?$/)[0]);
@@ -157,7 +164,7 @@ function importAotModule(moduleName) {
     /// the node-api-dotnet module.
     /// </summary>
     private const string LoadSystemAssemblyMJS = @"
-import dotnet from 'node-api-dotnet';
+import dotnet from 'node-api-dotnet/$(TargetFramework)';
 import * as path from 'node:path';
 import { fileURLToPath } from 'node:url';
 
@@ -172,7 +179,7 @@ function importAotModule(moduleName) {
     /// it augments the node-api-dotnet module.
     /// </summary>
     private const string LoadSystemAssemblyCJS = @"
-const dotnet = require('node-api-dotnet');
+const dotnet = require('node-api-dotnet/$(TargetFramework)');
 const path = require('node:path');
 
 const assemblyName = path.basename(__filename, __filename.match(/(\.[cm]?js)?$/)[0]);
@@ -209,6 +216,7 @@ public static void GenerateTypeDefinitions(
         IEnumerable<string> systemReferenceAssemblyDirectories,
         string typeDefinitionsPath,
         IDictionary<ModuleType, string> modulePaths,
+        string? targetFramework = null,
         bool isSystemAssembly = false,
         bool suppressWarnings = false)
     {
@@ -286,7 +294,7 @@ public static void GenerateTypeDefinitions(
                 string moduleFilePath = moduleTypeAndPath.Value;
 
                 SourceText generatedModule = generator.GenerateModuleLoader(
-                    moduleType, isSystemAssembly);
+                    moduleType, targetFramework, isSystemAssembly);
                 File.WriteAllText(moduleFilePath, generatedModule.ToString());
             }
         }
@@ -466,82 +474,94 @@ public SourceText GenerateTypeDefinitions(bool? autoCamelCase = null)
         return s;
     }
 
-    public SourceText GenerateModuleLoader(ModuleType moduleType, bool isSystemAssembly = false)
+    public SourceText GenerateModuleLoader(
+        ModuleType moduleType,
+        string? targetFramework,
+        bool isSystemAssembly = false)
     {
         var s = new SourceBuilder();
         s += GetGeneratedFileHeader();
 
-        if (_isModule)
+        s += GetLoaderJS(
+            moduleType,
+            _isModule ? AssemblyType.JSModule :
+                isSystemAssembly ? AssemblyType.SystemAssembly : AssemblyType.ApplicationAssembly,
+            targetFramework);
+
+        if (_isModule && moduleType == ModuleType.ES)
         {
-            if (moduleType == ModuleType.ES)
+            // Declare ES module exports.
+
+            bool isFirstMember = true;
+            bool hasDefaultExport = false;
+            foreach (MemberInfo member in _exportedMembers)
             {
-                s += LoadModuleMJS.Replace("    ", ""); // The SourceBuilder will auto-indent.
+                string exportName = GetExportName(member);
 
-                bool isFirstMember = true;
-                bool hasDefaultExport = false;
-                foreach (MemberInfo member in _exportedMembers)
+                if (member is PropertyInfo exportedProperty &&
+                    exportedProperty.SetMethod != null)
                 {
-                    string exportName = GetExportName(member);
-
-                    if (member is PropertyInfo exportedProperty &&
-                        exportedProperty.SetMethod != null)
-                    {
-                        ReportWarning(
-                            DiagnosticId.ESModulePropertiesAreConst,
-                            $"Module-level property '{exportName}' with setter will be " +
-                            "exported as read-only because ES module properties are constant.");
-                    }
+                    ReportWarning(
+                        DiagnosticId.ESModulePropertiesAreConst,
+                        $"Module-level property '{exportName}' with setter will be " +
+                        "exported as read-only because ES module properties are constant.");
+                }
 
-                    if (exportName == "default")
+                if (exportName == "default")
+                {
+                    hasDefaultExport = true;
+                }
+                else
+                {
+                    if (isFirstMember)
                     {
-                        hasDefaultExport = true;
+                        s++;
+                        isFirstMember = false;
                     }
-                    else
-                    {
-                        if (isFirstMember)
-                        {
-                            s++;
-                            isFirstMember = false;
-                        }
 
-                        s += $"export const {exportName} = exports.{exportName};";
-                    }
-                }
-
-                if (hasDefaultExport)
-                {
-                    s++;
-                    s += $"export default exports['default'];";
+                    s += $"export const {exportName} = exports.{exportName};";
                 }
             }
-            else if (moduleType == ModuleType.CommonJS)
-            {
-                s += LoadModuleCJS.Replace("    ", ""); // The SourceBuilder will auto-indent.
-            }
-            else
+
+            if (hasDefaultExport)
             {
-                throw new ArgumentException(
-                    "Invalid module type: " + moduleType, nameof(moduleType));
+                s++;
+                s += $"export default exports['default'];";
             }
         }
+
+        return s;
+    }
+
+    private static string GetLoaderJS(
+        ModuleType moduleType,
+        AssemblyType assemblyType,
+        string? targetFramework)
+    {
+        string loaderJS = (moduleType, assemblyType) switch
+        {
+            (ModuleType.CommonJS, AssemblyType.JSModule) => LoadModuleCJS,
+            (ModuleType.ES, AssemblyType.JSModule) => LoadModuleMJS,
+            (ModuleType.CommonJS, AssemblyType.ApplicationAssembly) => LoadAssemblyCJS,
+            (ModuleType.ES, AssemblyType.ApplicationAssembly) => LoadAssemblyMJS,
+            (ModuleType.CommonJS, AssemblyType.SystemAssembly) => LoadSystemAssemblyCJS,
+            (ModuleType.ES, AssemblyType.SystemAssembly) => LoadSystemAssemblyMJS,
+            _ => throw new ArgumentException(
+                "Invalid module type: " + moduleType, nameof(moduleType)),
+        };
+
+        loaderJS = loaderJS.Replace("    ", ""); // The SourceBuilder will auto-indent.
+
+        if (string.IsNullOrEmpty(targetFramework))
+        {
+            loaderJS = loaderJS.Replace("/$(TargetFramework)", string.Empty);
+        }
         else
         {
-            if (moduleType == ModuleType.ES)
-            {
-                s += isSystemAssembly ? LoadSystemAssemblyMJS : LoadAssemblyMJS;
-            }
-            else if (moduleType == ModuleType.CommonJS)
-            {
-                s += isSystemAssembly ? LoadSystemAssemblyCJS : LoadAssemblyCJS;
-            }
-            else
-            {
-                throw new ArgumentException(
-                    "Invalid module type: " + moduleType, nameof(moduleType));
-            }
+            loaderJS = loaderJS.Replace("$(TargetFramework)", targetFramework);
         }
 
-        return s;
+        return loaderJS;
     }
 
     private bool IsExported(MemberInfo member)

src/NodeApi/JSValueScope.cs

@@ -191,7 +191,6 @@ public JSValueScope(
             runtime ??= _parentScope?.Runtime ??
                     throw new ArgumentNullException(nameof(runtime), "A runtime is required.");
 
-            _parentScope = null;
             _env = env;
             ThreadId = Environment.CurrentManagedThreadId;
             Runtime = runtime;

test/JSProjectTests.cs

@@ -23,7 +23,8 @@ public class JSProjectTests
 
     public static IEnumerable<object[]> TestCases { get; } = ListTestCases(
         (testCaseName) => testCaseName.StartsWith("projects/") &&
-            IsCurrentTargetFramework(Path.GetFileName(testCaseName)));
+            (!testCaseName.Contains("-dynamic") ||
+                IsCurrentTargetFramework(Path.GetFileName(testCaseName))));
 
     private static bool IsCurrentTargetFramework(string target)
     {