Merge pull request #13997 from yujunjung/main

fix: exporting async module as library `type:  "module"`

Author: sokra

lib/library/ModuleLibraryPlugin.js

@@ -78,6 +78,10 @@ class ModuleLibraryPlugin extends AbstractLibraryPlugin {
 		const result = new ConcatSource(source);
 		const exportsInfo = moduleGraph.getExportsInfo(module);
 		const exports = [];
+		const isAsync = moduleGraph.isAsync(module);
+		if (isAsync) {
+			result.add(`__webpack_exports__ = await __webpack_exports__;\n`);
+		}
 		for (const exportInfo of exportsInfo.orderedExports) {
 			if (!exportInfo.provided) continue;
 			const varName = `__webpack_exports__${Template.toIdentifier(

test/configCases/async-library/0-create-library/a.js

@@ -0,0 +1 @@
+export const a = await Promise.resolve(42);

test/configCases/async-library/0-create-library/test.config.js

@@ -0,0 +1 @@
+exports.noTests = true;

test/configCases/async-library/0-create-library/webpack.config.js

@@ -0,0 +1,18 @@
+/** @type {import("../../../../types").Configuration} */
+module.exports = {
+	entry: "./a.js",
+	output: {
+		filename: "lib.js",
+		library: {
+			type: "module"
+		}
+	},
+	target: "node14",
+	optimization: {
+		minimize: true
+	},
+	experiments: {
+		topLevelAwait: true,
+		outputModule: true
+	}
+};

test/configCases/async-library/1-use-library/index.js

@@ -0,0 +1,5 @@
+it("should get valid export from library", () => {
+	return import("library").then(({ a }) => {
+		expect(a).toBe(42);
+	});
+});

test/configCases/async-library/1-use-library/webpack.config.js

@@ -0,0 +1,18 @@
+var path = require("path");
+
+/** @type {function(any, any): import("../../../../types").Configuration} */
+module.exports = (env, { testPath }) => ({
+	target: "node14",
+	output: {
+		chunkLoading: "import"
+	},
+	resolve: {
+		alias: {
+			library: path.resolve(testPath, "../0-create-library/lib.js")
+		}
+	},
+	experiments: {
+		topLevelAwait: true,
+		outputModule: true
+	}
+});