Handle reexports from dynamic entries across chunks (#2928)

src/Chunk.ts

@@ -98,9 +98,7 @@ function getGlobalName(
 		graph.warn({
 			code: 'MISSING_GLOBAL_NAME',
 			guess: module.variableName,
-			message: `No name was provided for external module '${
-				module.id
-			}' in output.globals – guessing '${module.variableName}'`,
+			message: `No name was provided for external module '${module.id}' in output.globals – guessing '${module.variableName}'`,
 			source: module.id
 		});
 		return module.variableName;
@@ -1088,7 +1086,10 @@ export default class Chunk {
 				}
 			}
 		}
-		if (module.isEntryPoint) {
+		if (
+			module.isEntryPoint ||
+			module.dynamicallyImportedBy.some(importer => importer.chunk !== this)
+		) {
 			const map = module.getExportNamesByVariable();
 			for (const exportedVariable of map.keys()) {
 				this.exports.add(exportedVariable);

test/function/samples/chunking-duplicate-reexport/_config.js

@@ -0,0 +1,8 @@
+const assert = require('assert');
+
+module.exports = {
+	description: 'handles duplicate reexports when using dynamic imports',
+	exports(exports) {
+		return exports.then(result => assert.deepStrictEqual(result, [{ answer: 42 }, { answer: 42 }]));
+	}
+};

test/function/samples/chunking-duplicate-reexport/chunk1.js

@@ -0,0 +1 @@
+export { answer } from './lib.js';

test/function/samples/chunking-duplicate-reexport/chunk2.js

@@ -0,0 +1 @@
+export { answer } from './lib.js';

test/function/samples/chunking-duplicate-reexport/lib.js

@@ -0,0 +1 @@
+export const answer = 42;

test/function/samples/chunking-duplicate-reexport/main.js

@@ -0,0 +1 @@
+export default Promise.all([import('./chunk1.js'), import('./chunk2.js')]);