alexander-akait · Sep 13, 2026 · Sep 12, 2026 · Sep 13, 2026 · Sep 13, 2026
diff --git a/.changeset/013-esm-reexport-external-target.md b/.changeset/013-esm-reexport-external-target.md
@@ -0,0 +1,5 @@
+---
+"webpack": patch
+---
+
+Use configured external requests in ESM star reexports; reject property paths.
diff --git a/lib/ExternalModule.js b/lib/ExternalModule.js
@@ -1239,6 +1239,17 @@ class ExternalModule extends Module {
 		return this._resolveExternalType(this.externalType) !== "module";
 	}
 
+	/**
+	 * The request this external resolves to for its own type, with the record form
+	 * narrowed to its entry. An array is a module specifier plus a property path.
+	 * @returns {string | string[] | undefined} the resolved request
+	 */
+	getResolvedRequest() {
+		return /** @type {string | string[] | undefined} */ (
+			this._getRequestAndExternalType().request
+		);
+	}
+
 	/**
 	 * Get request and external type.
 	 * @private

diff --git a/lib/errors/ExternalStarReexportError.js b/lib/errors/ExternalStarReexportError.js
@@ -0,0 +1,44 @@
+/*
+	MIT License http://www.opensource.org/licenses/mit-license.php
+	Author Alexander Akait @alexander-akait
+*/
+
+"use strict";
+
+const WebpackError = require("./WebpackError");
+
+/** @import ExternalModule from "../ExternalModule" */
+/** @import Module from "../Module" */
+
+/**
+ * Error raised when a `module` library reexports everything from an external
+ * whose request names a property path instead of a module.
+ */
+class ExternalStarReexportError extends WebpackError {
+	/**
+	 * Captures the external and the library entry reexporting from it.
+	 * @param {ExternalModule} externalModule the reexported external
+	 * @param {Module} module the library entry module
+	 */
+	constructor(externalModule, module) {
+		const request = /** @type {string[]} */ (
+			externalModule.getResolvedRequest()
+		);
+		super(
+			`Can't 'export * from ${JSON.stringify(
+				externalModule.userRequest
+			)}': the external is configured as ${JSON.stringify(
+				request
+			)}, which is a property of ${JSON.stringify(
+				request[0]
+			)} and has no module specifier to reexport. Reexport the names explicitly or configure the external without a property path.`
+		);
+
+		/** @type {string} */
+		this.name = "ExternalStarReexportError";
+		/** @type {Module} */
+		this.module = module;
+	}
+}
+
+module.exports = ExternalStarReexportError;
diff --git a/lib/html/HtmlModulesPlugin.js b/lib/html/HtmlModulesPlugin.js
@@ -73,11 +73,10 @@ const getCssModulesPlugin = memoize(() => require("../css/CssModulesPlugin"));
 /** @typedef {import("../../declarations/WebpackOptions").OutputHtmlOptions["favicon"]} FaviconOption */
 /** @typedef {import("../../declarations/WebpackOptions").OutputHtmlOptions["manifest"]} ManifestOption */
 /** @typedef {Exclude<HtmlFaviconIcon, string>} FaviconIcon */
-/** @import Chunk from "../Chunk" */
+/** @import Chunk, { ChunkFilenameTemplate } from "../Chunk" */
 /** @import ChunkGraph from "../ChunkGraph" */
 /** @import Compiler from "../Compiler" */
 /** @import Module from "../Module" */
-/** @import { ChunkFilenameTemplate } from "../Chunk" */
 /** @typedef {import("../Compilation").EntryData} EntryData */
 /** @import { HtmlModuleBuildInfo } from "./HtmlModule" */
 /** @import HtmlParser from "./HtmlParser" */

diff --git a/lib/library/ModuleLibraryPlugin.js b/lib/library/ModuleLibraryPlugin.js
@@ -14,6 +14,7 @@ const Template = require("../Template");
 const HarmonyExportExpressionDependency = require("../dependencies/HarmonyExportExpressionDependency");
 const HarmonyExportImportedSpecifierDependency = require("../dependencies/HarmonyExportImportedSpecifierDependency");
 const HarmonyExportSpecifierDependency = require("../dependencies/HarmonyExportSpecifierDependency");
+const ExternalStarReexportError = require("../errors/ExternalStarReexportError");
 const JavascriptModulesPlugin = require("../javascript/JavascriptModulesPlugin");
 const ConcatenatedModule = require("../optimize/ConcatenatedModule");
 const { InlinedUsedName } = require("../optimize/InlineExports");
@@ -368,6 +369,7 @@ class ModuleLibraryPlugin extends AbstractLibraryPlugin {
 				}
 			}
 		}
+		this._checkStarReexportedExternals(module, compilation);
 		moduleGraph.addExtraReason(module, "used as library export");
 		let entries = libraryEntryModules.get(compilation);
 		if (entries === undefined) {
@@ -377,6 +379,61 @@ class ModuleLibraryPlugin extends AbstractLibraryPlugin {
 		entries.add(module);
 	}
 
+	/**
+	 * Reports every external the entry star-reexports whose request names a property
+	 * path, which `export *` has no way to reference.
+	 * @param {Module} module the library entry module
+	 * @param {Compilation} compilation the compilation
+	 * @returns {void}
+	 */
+	_checkStarReexportedExternals(module, compilation) {
+		const { moduleGraph } = compilation;
+		/** @type {Set<Module>} */
+		const visitedReexportModules = new Set([module]);
+		/** @type {Module[]} */
+		const queue = [module];
+		/** @type {Set<ExternalModule>} */
+		const unsupportedExternals = new Set();
+
+		for (const current of queue) {
+			for (const connection of moduleGraph.getOutgoingConnections(current)) {
+				const dep = connection.dependency;
+
+				// Only handle star-reexport statement
+				if (
+					!(dep instanceof HarmonyExportImportedSpecifierDependency) ||
+					dep.name !== null
+				) {
+					continue;
+				}
+				const importedModule = connection.resolvedModule;
+
+				// Only a module providing unknown exports keeps its reexport rendered
+				if (
+					moduleGraph.getExportsInfo(importedModule)._otherExportsInfo
+						.provided !== null
+				) {
+					continue;
+				}
+				if (importedModule instanceof ExternalModule) {
+					const request = importedModule.getResolvedRequest();
+					if (Array.isArray(request) && request.length > 1) {
+						unsupportedExternals.add(importedModule);
+					}
+				} else if (!visitedReexportModules.has(importedModule)) {
+					visitedReexportModules.add(importedModule);
+					queue.push(importedModule);
+				}
+			}
+		}
+
+		for (const externalModule of unsupportedExternals) {
+			compilation.errors.push(
+				new ExternalStarReexportError(externalModule, module)
+			);
+		}
+	}
+
 	/**
 	 * Returns preprocess as needed by overriding.
 	 * @param {LibraryOptions} library normalized library option
@@ -449,7 +506,14 @@ class ModuleLibraryPlugin extends AbstractLibraryPlugin {
 					) {
 						// Handle export * from 'external'
 						if (importedModule instanceof ExternalModule) {
-							moduleRequests.add(importedModule.userRequest);
+							const request = importedModule.getResolvedRequest();
+							// A property path is reported by `_checkStarReexportedExternals`,
+							// and an absent one by the external's own build
+							if (typeof request === "string") {
+								moduleRequests.add(request);
+							} else if (Array.isArray(request) && request.length === 1) {
+								moduleRequests.add(request[0]);
+							}
 						} else if (!visitedReexportModules.has(importedModule)) {
 							visitedReexportModules.add(importedModule);
 							resolveDynamicStarReexport(importedModule, true);

diff --git a/test/configCases/library/module-reexport-external-property-path/errors.js b/test/configCases/library/module-reexport-external-property-path/errors.js
@@ -0,0 +1,8 @@
+"use strict";
+
+module.exports = [
+	[
+		/Can't 'export \* from "property-path"'/,
+		/configured as \["nested-module","inner"\]/
+	]
+];
diff --git a/test/configCases/library/module-reexport-external-property-path/index.js b/test/configCases/library/module-reexport-external-property-path/index.js
@@ -0,0 +1,6 @@
+import * as library from "./library.mjs";
+
+it("should reexport the external without a property path", () => {
+	expect(library.value).toBe(1);
+	expect(Object.keys(library)).toEqual(["value"]);
+});
diff --git a/test/configCases/library/module-reexport-external-property-path/library.js b/test/configCases/library/module-reexport-external-property-path/library.js
@@ -0,0 +1,2 @@
+export * from "property-path";
+export * from "plain-alias";
diff --git a/test/configCases/library/module-reexport-external-property-path/test.config.js b/test/configCases/library/module-reexport-external-property-path/test.config.js
@@ -0,0 +1,14 @@
+"use strict";
+
+module.exports = {
+	/**
+	 * @returns {string} emitted test bundle
+	 */
+	findBundle() {
+		return "main.mjs";
+	},
+	modules: {
+		"actual-module": { value: 1 },
+		"nested-module": { inner: { innerValue: 2 } }
+	}
+};
diff --git a/test/configCases/library/module-reexport-external-property-path/webpack.config.js b/test/configCases/library/module-reexport-external-property-path/webpack.config.js
@@ -0,0 +1,18 @@
+"use strict";
+
+/** @type {import("../../../../").Configuration} */
+module.exports = {
+	mode: "development",
+	entry: {
+		main: "./index.js",
+		library: { import: "./library.js", library: { type: "module" } }
+	},
+	output: { module: true, filename: "[name].mjs" },
+	externalsType: "module",
+	externals: {
+		"./library.mjs": "./library.mjs",
+		"plain-alias": "actual-module",
+		"property-path": ["nested-module", "inner"]
+	},
+	optimization: { minimize: false }
+};
diff --git a/test/configCases/library/module-reexport-external-target/index.js b/test/configCases/library/module-reexport-external-target/index.js
@@ -0,0 +1,8 @@
+import * as library from "./library.mjs";
+
+it("should reexport the configured external targets instead of their aliases", () => {
+	expect(library.value).toBe(1);
+	expect(library.arrayValue).toBe(2);
+	expect(library.recordValue).toBe(3);
+	expect(Object.keys(library)).toEqual(["arrayValue", "recordValue", "value"]);
+});
diff --git a/test/configCases/library/module-reexport-external-target/library.js b/test/configCases/library/module-reexport-external-target/library.js
@@ -0,0 +1,4 @@
+export * from "alias";
+export * from "alias-again";
+export * from "array-alias";
+export * from "record-alias";
diff --git a/test/configCases/library/module-reexport-external-target/test.config.js b/test/configCases/library/module-reexport-external-target/test.config.js
@@ -0,0 +1,16 @@
+"use strict";
+
+module.exports = {
+	/**
+	 * @param {number} index configuration index
+	 * @returns {string} emitted test bundle
+	 */
+	findBundle(index) {
+		return `main${index}.mjs`;
+	},
+	modules: {
+		"actual-module": { value: 1 },
+		"actual-array-module": { arrayValue: 2 },
+		"actual-record-module": { recordValue: 3 }
+	}
+};
diff --git a/test/configCases/library/module-reexport-external-target/webpack.config.js b/test/configCases/library/module-reexport-external-target/webpack.config.js
@@ -0,0 +1,28 @@
+"use strict";
+
+/** @type {import("../../../../").Configuration[]} */
+module.exports = [
+	{ type: "module", minimize: false },
+	{ type: "module", minimize: true },
+	{ type: "modern-module", minimize: false },
+	{ type: "modern-module", minimize: true }
+].map(({ type, minimize }, index) => ({
+	mode: minimize ? "production" : "development",
+	entry: {
+		main: "./index.js",
+		library: { import: "./library.js", library: { type } }
+	},
+	output: { module: true, filename: `[name]${index}.mjs` },
+	externalsType: "module",
+	externals: {
+		"./library.mjs": `./library${index}.mjs`,
+		alias: "actual-module",
+		"alias-again": "actual-module",
+		"array-alias": ["actual-array-module"],
+		"record-alias": {
+			module: "actual-record-module",
+			commonjs: "unused-commonjs-module"
+		}
+	},
+	optimization: { minimize }
+}));
diff --git a/types.d.ts b/types.d.ts
@@ -9001,6 +9001,12 @@ declare class ExternalModule extends Module {
 		normalModuleFactory: NormalModuleFactory
 	): void;
 	canBeWrappedInConcatenation(): boolean;
+
+	/**
+	 * The request this external resolves to for its own type, with the record form
+	 * narrowed to its entry. An array is a module specifier plus a property path.
+	 */
+	getResolvedRequest(): undefined | string | string[];
 	static getCompilationHooks: (compilation: Compilation) => {
 		/**
 		 * @since 5.106.0
Original file line number	Diff line number	Diff line change
		@@ -0,0 +1,2 @@
		export * from "property-path";
		export * from "plain-alias";