fix: deferred modules define order and transitive deferred module not emitted correctly in concatenated modules

lib/optimize/ConcatenatedModule.js

@@ -23,6 +23,7 @@ const Template = require("../Template");
 const { DEFAULTS } = require("../config/defaults");
 const HarmonyImportDependency = require("../dependencies/HarmonyImportDependency");
 const HarmonyImportSideEffectDependency = require("../dependencies/HarmonyImportSideEffectDependency");
+const HarmonyImportSpecifierDependency = require("../dependencies/HarmonyImportSpecifierDependency");
 const JavascriptParser = require("../javascript/JavascriptParser");
 const {
 	getMakeDeferredNamespaceModeFromExportsType,
@@ -1832,6 +1833,25 @@ ${defineGetters}`
 				if (!source) continue;
 				result.add(source);
 			}
+
+			if (info.type === "external" && info.deferred) {
+				const moduleId = JSON.stringify(chunkGraph.getModuleId(info.module));
+				const loader = getOptimizedDeferredModule(
+					runtimeTemplate,
+					info.module.getExportsType(
+						moduleGraph,
+						/** @type {BuildMeta} */
+						(this.rootModule.buildMeta).strictHarmonyModule
+					),
+					moduleId,
+					// an async module will opt-out of the concat module optimization.
+					[]
+				);
+				runtimeRequirements.add(RuntimeGlobals.require);
+				result.add(
+					`\n// DEFERRED EXTERNAL MODULE: ${info.module.readableIdentifier(requestShortener)}\nvar ${info.deferredName} = ${loader};`
+				);
+			}
 		}
 
 		/** @type {InitFragment<ChunkRenderContext>[]} */
@@ -1855,10 +1875,19 @@ ${defineGetters}`
 						for (const dep of info.module.dependencies) {
 							if (
 								!(/** @type {HarmonyImportDependency} */ (dep).defer) &&
-								dep instanceof HarmonyImportSideEffectDependency
+								(dep instanceof HarmonyImportSideEffectDependency ||
+									dep instanceof HarmonyImportSpecifierDependency)
 							) {
 								const referredModule = moduleGraph.getModule(dep);
-								if (!referredModule) continue;
+								if (!referredModule) {
+									if (dep instanceof HarmonyImportSideEffectDependency) {
+										continue;
+									} else {
+										throw new Error(
+											"Deferred module used, but no module in the graph."
+										);
+									}
+								}
 								if (moduleGraph.isDeferred(referredModule)) {
 									const deferredModuleInfo = /** @type {ExternalModuleInfo} */ (
 										modulesWithInfo.find(
@@ -1887,6 +1916,8 @@ ${defineGetters}`
 					break;
 				}
 				case "external": {
+					// deferred case is handled in the "const info of modulesWithInfo" loop above
+					if (!info.deferred) {
 						result.add(
 							`\n// EXTERNAL MODULE: ${info.module.readableIdentifier(
 								requestShortener
@@ -1906,22 +1937,9 @@ ${defineGetters}`
 							isConditional = true;
 							result.add(`if (${condition}) {\n`);
 						}
-					const moduleId = JSON.stringify(chunkGraph.getModuleId(info.module));
-					if (info.deferred) {
-						const loader = getOptimizedDeferredModule(
-							runtimeTemplate,
-							info.module.getExportsType(
-								moduleGraph,
-								/** @type {BuildMeta} */
-								(this.rootModule.buildMeta).strictHarmonyModule
-							),
-							moduleId,
-							// an async module will opt-out of the concat module optimization.
-							[]
+						const moduleId = JSON.stringify(
+							chunkGraph.getModuleId(info.module)
 						);
-						result.add(`var ${info.deferredName} = ${loader};`);
-						name = info.deferredName;
-					} else {
 						result.add(`var ${info.name} = __webpack_require__(${moduleId});`);
 						name = info.name;
 					}

lib/runtime/MakeDeferredNamespaceObjectRuntime.js

@@ -174,7 +174,7 @@ class MakeDeferredNamespaceObjectRuntimeModule extends HelperRuntimeModule {
 				])},`,
 				`ownKeys: ${runtimeTemplate.basicFunction("", [
 					init,
-					`var keys = Reflect.ownKeys(ns).filter(${runtimeTemplate.expressionFunction('x !== "then"', "x")}).concat([Symbol.toStringTag]);`,
+					`var keys = Reflect.ownKeys(ns).filter(${runtimeTemplate.expressionFunction('x !== "then" && x !== Symbol.toStringTag', "x")}).concat([Symbol.toStringTag]);`,
 					"return keys;"
 				])},`,
 				`getOwnPropertyDescriptor: ${runtimeTemplate.basicFunction("_, name", [

test/configCases/defer-import/concatenated-1/a.js

@@ -0,0 +1,3 @@
+import { a } from 'mod'
+
+Object.keys(a).forEach(() => { })

test/configCases/defer-import/concatenated-1/b.js

@@ -0,0 +1,3 @@
+import defer * as m from 'mod'
+
+Object.keys(m).forEach(() => {})

test/configCases/defer-import/concatenated-1/index.js

@@ -0,0 +1,3 @@
+it('should compile and load', () => {
+	require('./main.js');
+})

test/configCases/defer-import/concatenated-1/main.js

@@ -0,0 +1,2 @@
+import './a'
+import './b'

test/configCases/defer-import/concatenated-1/node_modules/mod/index.js

@@ -0,0 +1 @@
+export { a } from './re-export'

test/configCases/defer-import/concatenated-1/node_modules/mod/package.json

@@ -0,0 +1,5 @@
+{
+    "sideEffects": false,
+    "main": "./index.js",
+    "name": "mod"
+}

test/configCases/defer-import/concatenated-1/node_modules/mod/re-export.js

@@ -0,0 +1,3 @@
+export function a() {
+
+}

test/configCases/defer-import/concatenated-1/webpack.config.js

@@ -0,0 +1,12 @@
+"use strict";
+
+/** @type {import("../../../../types").Configuration} */
+module.exports = {
+	target: [`async-node${process.versions.node.split(".").map(Number)[0]}`],
+	optimization: {
+		concatenateModules: true
+	},
+	experiments: {
+		deferImport: true
+	}
+};

test/configCases/defer-import/concatenated-2/a.js

@@ -0,0 +1,5 @@
+import defer * as mod from 'mod'
+
+export function b() {
+    mod.fn()
+}

test/configCases/defer-import/concatenated-2/index.js

@@ -0,0 +1,3 @@
+it('should compile and load', () => {
+	require('./main.js');
+})

test/configCases/defer-import/concatenated-2/main.js

@@ -0,0 +1,5 @@
+import { fn } from 'mod'
+import { b } from './a'
+
+fn()
+b()

test/configCases/defer-import/concatenated-2/node_modules/mod/index.js

@@ -0,0 +1 @@
+export { fn } from './re-export'

test/configCases/defer-import/concatenated-2/node_modules/mod/package.json

@@ -0,0 +1,5 @@
+{
+    "sideEffects": false,
+    "main": "./index.js",
+    "name": "mod"
+}

test/configCases/defer-import/concatenated-2/node_modules/mod/re-export.js

@@ -0,0 +1 @@
+export function fn() {}

test/configCases/defer-import/concatenated-2/webpack.config.js

@@ -0,0 +1,12 @@
+"use strict";
+
+/** @type {import("../../../../types").Configuration} */
+module.exports = {
+	target: [`async-node${process.versions.node.split(".").map(Number)[0]}`],
+	optimization: {
+		concatenateModules: true
+	},
+	experiments: {
+		deferImport: true
+	}
+};