support destructuring assignment with AwaitExpression

lib/dependencies/ImportParserPlugin.js

@@ -27,6 +27,8 @@ class ImportParserPlugin {
 	}
 
 	apply(parser) {
+		const exportsFromEnumerable = enumerable =>
+			Array.from(enumerable, e => [e]);
 		parser.hooks.importCall.tap("ImportParserPlugin", expr => {
 			const param = parser.evaluateExpression(expr.source);
 
@@ -184,7 +186,7 @@ class ImportParserPlugin {
 						if (typeof importOptions.webpackExports === "string") {
 							exports = [[importOptions.webpackExports]];
 						} else {
-							exports = Array.from(importOptions.webpackExports, e => [e]);
+							exports = exportsFromEnumerable(importOptions.webpackExports);
 						}
 					}
 				}
@@ -205,6 +207,20 @@ class ImportParserPlugin {
 				mode = "lazy";
 			}
 
+			const referencedPropertiesInDestructuring =
+				parser.destructuringAssignmentPropertiesFor(expr);
+			if (referencedPropertiesInDestructuring) {
+				if (exports) {
+					parser.state.module.addWarning(
+						new UnsupportedFeatureWarning(
+							`\`webpackExports\` could not be used with destructuring assignment.`,
+							expr.loc
+						)
+					);
+				}
+				exports = exportsFromEnumerable(referencedPropertiesInDestructuring);
+			}
+
 			if (param.isString()) {
 				if (mode === "eager") {
 					const dep = new ImportEagerDependency(

lib/javascript/JavascriptParser.js

@@ -1927,7 +1927,12 @@ class JavascriptParser extends Parser {
 			for (const id of set) keys.add(id);
 		}
 
-		this.destructuringAssignmentProperties.set(expression.right, keys);
+		this.destructuringAssignmentProperties.set(
+			expression.right.type === "AwaitExpression"
+				? expression.right.argument
+				: expression.right,
+			keys
+		);
 
 		if (expression.right.type === "AssignmentExpression") {
 			this.preWalkAssignmentExpression(expression.right);
@@ -2183,7 +2188,12 @@ class JavascriptParser extends Parser {
 		const keys = this._preWalkObjectPattern(declarator.id);
 
 		if (!keys) return;
-		this.destructuringAssignmentProperties.set(declarator.init, keys);
+		this.destructuringAssignmentProperties.set(
+			declarator.init.type === "AwaitExpression"
+				? declarator.init.argument
+				: declarator.init,
+			keys
+		);
 
 		if (declarator.init.type === "AssignmentExpression") {
 			this.preWalkAssignmentExpression(declarator.init);

test/__snapshots__/StatsTestCases.basictest.js.snap

@@ -1840,9 +1840,9 @@ webpack x.x.x compiled successfully in X ms"
 `;
 
 exports[`StatsTestCases should print correct stats for output-module 1`] = `
-"asset main.mjs 10 KiB [emitted] [javascript module] (name: main)
-asset 52.mjs 402 bytes [emitted] [javascript module]
-runtime modules 6.07 KiB 8 modules
+"asset main.mjs 9.57 KiB [emitted] [javascript module] (name: main)
+asset 52.mjs 358 bytes [emitted] [javascript module]
+runtime modules 5.8 KiB 7 modules
 orphan modules 38 bytes [orphan] 1 module
 cacheable modules 263 bytes
   ./index.js + 1 modules 225 bytes [built] [code generated]

test/cases/chunks/destructuring-assignment/dir1/a.js

@@ -0,0 +1,3 @@
+export const a = 1;
+export default 3;
+export const usedExports = __webpack_exports_info__.usedExports;

test/cases/chunks/destructuring-assignment/index.js

@@ -0,0 +1,12 @@
+it("should load only used exports", async (done) => {
+	const { default: def, usedExports } = await import("./dir1/a");
+	expect(def).toBe(3);
+	expect(usedExports).toEqual(["default", "usedExports"]);
+	done();
+});
+
+it("should get warning on using 'webpackExports' with destructuring assignment", async (done) => {
+	const { default: def } = await import(/* webpackExports: ["a"] */"./dir1/a?2");
+	expect(def).toBe(3);
+	done();
+});

test/cases/chunks/destructuring-assignment/warnings.js

@@ -0,0 +1,3 @@
+module.exports = [
+	[/`webpackExports` could not be used with destructuring assignment./]
+];