add `node-commonjs` external type to use `createRequire` for commonjs externals

for `module` externals, fallback to `import()` when not in module mode

lib/ExternalModule.js

@@ -94,6 +94,36 @@ const getSourceForCommonJsExternal = moduleAndSpecifiers => {
 	};
 };
 
+/**
+ * @param {string|string[]} moduleAndSpecifiers the module request
+ * @returns {SourceData} the generated source
+ */
+const getSourceForCommonJsExternalInNodeModule = moduleAndSpecifiers => {
+	const chunkInitFragments = [
+		new InitFragment(
+			'import { createRequire as __WEBPACK_EXTERNAL_createRequire } from "module";\n',
+			InitFragment.STAGE_HARMONY_IMPORTS,
+			0,
+			"external module node-commonjs"
+		)
+	];
+	if (!Array.isArray(moduleAndSpecifiers)) {
+		return {
+			expression: `__WEBPACK_EXTERNAL_createRequire(import.meta.url)(${JSON.stringify(
+				moduleAndSpecifiers
+			)})`,
+			chunkInitFragments
+		};
+	}
+	const moduleName = moduleAndSpecifiers[0];
+	return {
+		expression: `__WEBPACK_EXTERNAL_createRequire(import.meta.url)(${JSON.stringify(
+			moduleName
+		)})${propertyAccess(moduleAndSpecifiers, 1)}`,
+		chunkInitFragments
+	};
+};
+
 /**
  * @param {string|string[]} moduleAndSpecifiers the module request
  * @param {RuntimeTemplate} runtimeTemplate the runtime template
@@ -400,9 +430,17 @@ class ExternalModule extends Module {
 				break;
 			case "system":
 			case "module":
-				if (!Array.isArray(request) || request.length === 1) {
-					this.buildMeta.exportsType = "namespace";
-					canMangle = true;
+				if (this.buildInfo.module) {
+					if (!Array.isArray(request) || request.length === 1) {
+						this.buildMeta.exportsType = "namespace";
+						canMangle = true;
+					}
+				} else {
+					this.buildMeta.async = true;
+					if (!Array.isArray(request) || request.length === 1) {
+						this.buildMeta.exportsType = "namespace";
+						canMangle = false;
+					}
 				}
 				break;
 			case "script":
@@ -440,11 +478,6 @@ class ExternalModule extends Module {
 
 	_getRequestAndExternalType() {
 		let { request, externalType } = this;
-		let match;
-		if ((match = /^([^/]+)\/([^/]+)$/.exec(externalType))) {
-			// TODO add chunk specific code generation, and get that from the chunk format
-			externalType = this.buildInfo.module ? match[2] : match[1];
-		}
 		if (typeof request === "object" && !Array.isArray(request))
 			request = request[externalType];
 		return { request, externalType };
@@ -466,6 +499,10 @@ class ExternalModule extends Module {
 			case "commonjs2":
 			case "commonjs-module":
 				return getSourceForCommonJsExternal(request);
+			case "node-commonjs":
+				return this.buildInfo.module
+					? getSourceForCommonJsExternalInNodeModule(request)
+					: getSourceForCommonJsExternal(request);
 			case "amd":
 			case "amd-require":
 			case "umd":
@@ -483,6 +520,17 @@ class ExternalModule extends Module {
 			case "script":
 				return getSourceForScriptExternal(request, runtimeTemplate);
 			case "module":
+				if (!this.buildInfo.module) {
+					if (!runtimeTemplate.supportsDynamicImport()) {
+						throw new Error(
+							"The target environment doesn't support dynamic import() syntax so it's not possible to use external type 'module' within a script" +
+								(runtimeTemplate.supportsEcmaScriptModuleSyntax()
+									? "\nDid you mean to build a EcmaScript Module ('output.module: true')?"
+									: "")
+						);
+					}
+					return getSourceForImportExternal(request, runtimeTemplate);
+				}
 				if (!runtimeTemplate.supportsEcmaScriptModuleSyntax()) {
 					throw new Error(
 						"The target environment doesn't support EcmaScriptModule syntax so it's not possible to use external type 'module'"

lib/WebpackOptionsApply.js

@@ -113,7 +113,7 @@ class WebpackOptionsApply extends OptionsApply {
 		if (options.externalsPresets.nwjs) {
 			//@ts-expect-error https://github.com/microsoft/TypeScript/issues/41697
 			const ExternalsPlugin = require("./ExternalsPlugin");
-			new ExternalsPlugin("commonjs/module", "nw.gui").apply(compiler);
+			new ExternalsPlugin("node-commonjs", "nw.gui").apply(compiler);
 		}
 		if (options.externalsPresets.webAsync) {
 			//@ts-expect-error https://github.com/microsoft/TypeScript/issues/41697

lib/electron/ElectronTargetPlugin.js

@@ -22,7 +22,7 @@ class ElectronTargetPlugin {
 	 * @returns {void}
 	 */
 	apply(compiler) {
-		new ExternalsPlugin("commonjs/module", [
+		new ExternalsPlugin("node-commonjs", [
 			"clipboard",
 			"crash-reporter",
 			"electron",
@@ -34,7 +34,7 @@ class ElectronTargetPlugin {
 		]).apply(compiler);
 		switch (this._context) {
 			case "main":
-				new ExternalsPlugin("commonjs/module", [
+				new ExternalsPlugin("node-commonjs", [
 					"app",
 					"auto-updater",
 					"browser-window",
@@ -54,7 +54,7 @@ class ElectronTargetPlugin {
 				break;
 			case "preload":
 			case "renderer":
-				new ExternalsPlugin("commonjs/module", [
+				new ExternalsPlugin("node-commonjs", [
 					"desktop-capturer",
 					"ipc-renderer",
 					"remote",

lib/node/NodeTargetPlugin.js

@@ -69,7 +69,7 @@ class NodeTargetPlugin {
 	 * @returns {void}
 	 */
 	apply(compiler) {
-		new ExternalsPlugin("commonjs/module", builtins).apply(compiler);
+		new ExternalsPlugin("node-commonjs", builtins).apply(compiler);
 	}
 }