Use ESM instead of CJS. Potentially fixes #160

Author: Thomas Krause

src/NodeJS/Javascript/Servers/OutOfProcess/Http/Http11Server.ts

@@ -118,12 +118,8 @@ function serverOnRequestListener(req: http.IncomingMessage, res: http.ServerResp
                     }
                 } else if (invocationRequest.moduleSourceType === ModuleSourceType.File) {
                     const resolvedPath = path.resolve(projectDir, invocationRequest.moduleSource);
-                    if (resolvedPath.endsWith('.mjs')) {
                         exports = await import(/* webpackIgnore: true */ 'file:///' + resolvedPath.replaceAll('\\', '/'));
                     } else {
-                        exports = __non_webpack_require__(resolvedPath);
-                    }
-                } else {
                     respondWithError(res, `Invalid module source type: ${invocationRequest.moduleSourceType}.`);
                     return;
                 }
@@ -135,7 +131,7 @@ function serverOnRequestListener(req: http.IncomingMessage, res: http.ServerResp
                 // Get function to invoke
                 let functionToInvoke: Function;
                 if (invocationRequest.exportName != null) {
-                    functionToInvoke = exports[invocationRequest.exportName];
+                    functionToInvoke = exports[invocationRequest.exportName] ?? exports.default?.[invocationRequest.exportName];
                     if (functionToInvoke == null) {
                         respondWithError(res, `The module ${getTempIdentifier(invocationRequest)} has no export named ${invocationRequest.exportName}.`);
                         return;

src/NodeJS/Javascript/Servers/OutOfProcess/Http/Http20Server.ts

@@ -104,12 +104,8 @@ function serverOnRequestListener(req: http2.Http2ServerRequest, res: http2.Http2
                     }
                 } else if (invocationRequest.moduleSourceType === ModuleSourceType.File) {
                     const resolvedPath = path.resolve(projectDir, invocationRequest.moduleSource);
-                    if (resolvedPath.endsWith('.mjs')) {
                         exports = await import(/* webpackIgnore: true */ 'file:///' + resolvedPath.replaceAll('\\', '/'));
                     } else {
-                        exports = __non_webpack_require__(resolvedPath);
-                    }
-                } else {
                     respondWithError(res, `Invalid module source type: ${invocationRequest.moduleSourceType}.`);
                     return;
                 }
@@ -121,7 +117,7 @@ function serverOnRequestListener(req: http2.Http2ServerRequest, res: http2.Http2
                 // Get function to invoke
                 let functionToInvoke: Function;
                 if (invocationRequest.exportName != null) {
-                    functionToInvoke = exports[invocationRequest.exportName];
+                    functionToInvoke = exports[invocationRequest.exportName] ?? exports.default?.[invocationRequest.exportName];
                     if (functionToInvoke == null) {
                         respondWithError(res, `The module ${getTempIdentifier(invocationRequest)} has no export named ${invocationRequest.exportName}.`);
                         return;

src/NodeJS/Javascript/package.json

@@ -1,5 +1,6 @@
 {
     "private": true,
+    "type": "module",
     "scripts": {
         "build": "echo ------ Yarn Install ------ && yarn install && echo ------ Webpack Compile ------ && webpack"
     },

src/NodeJS/Javascript/webpack.config.js

@@ -1,13 +1,16 @@
-const path = require('path');
+import * as path from 'path';
+import { fileURLToPath } from 'url';
 
-module.exports = env => {
+const __dirname = path.dirname(fileURLToPath(import.meta.url));
+
+export default env => {
 
     let mode = env.mode.toLowerCase() === 'release' ? 'production' : 'development'; // Default to development, production mode minifies scripts
     console.log(`Mode: ${mode}.`);
 
     return {
         mode: mode,
-        target: 'node',
+        target: 'node14',
         resolve: {
             extensions: ['.ts', '.js']
         },
@@ -19,9 +22,14 @@ module.exports = env => {
         entry: env.entry,
         output: {
             hashFunction: 'xxhash64',
-            libraryTarget: 'commonjs2',
+            library: {
+                type: 'module'
+            },
             path: path.join(__dirname, 'bin', env.mode),
             filename: path.basename(env.entry, path.extname(env.entry)) + '.js'
+        },
+        experiments: {
+            outputModule: true
         }
     };
 }; 

src/NodeJS/NodeJSServiceImplementations/OutOfProcess/NodeJSProcessFactory.cs

@@ -48,7 +48,7 @@ internal ProcessStartInfo CreateStartInfo(string nodeServerScript)
 #endif
             var startInfo = new ProcessStartInfo(_nodeJSProcessOptions.ExecutablePath!) // ConfigureNodeJSProcessOptions sets ExecutablePath to "node" if user specified value is null, whitespace or an empty string
             {
-                Arguments = $"{_nodeJSProcessOptions.NodeAndV8Options} -e \"{nodeServerScript}\" -- --parentPid {currentProcessPid} --port {_nodeJSProcessOptions.Port}",
+                Arguments = $"{_nodeJSProcessOptions.NodeAndV8Options} --input-type=module -e \"{nodeServerScript}\" -- --parentPid {currentProcessPid} --port {_nodeJSProcessOptions.Port}",
                 UseShellExecute = false,
                 RedirectStandardInput = true,
                 RedirectStandardOutput = true,

test/NodeJS/NodeJSServiceImplementations/OutOfProcess/NodeJSProcessFactoryUnitTests.cs

@@ -42,7 +42,7 @@ public void CreateStartInfo_CreatesStartInfo()
 #else
             int currentProcessPid = Process.GetCurrentProcess().Id;
 #endif
-            Assert.Equal($"{dummyNodeAndV8Options} -e \"{dummyNodeServerScript}\" -- --parentPid {currentProcessPid} --port {dummyPort}", result.Arguments);
+            Assert.Equal($"{dummyNodeAndV8Options} --input-type=module -e \"{dummyNodeServerScript}\" -- --parentPid {currentProcessPid} --port {dummyPort}", result.Arguments);
             Assert.False(result.UseShellExecute);
             Assert.True(result.RedirectStandardInput);
             Assert.True(result.RedirectStandardOutput);