fixes #7499

lib/optimize/ConcatenatedModule.js

@@ -281,6 +281,7 @@ class ConcatenatedModule extends Module {
 
 		// Info from Factory
 		this.rootModule = rootModule;
+		this.factoryMeta = rootModule.factoryMeta;
 
 		// Info from Compilation
 		this.index = rootModule.index;

test/cases/side-effects/missing-module-7499/example/constants.js

@@ -0,0 +1 @@
+export const hello = 'world'

test/cases/side-effects/missing-module-7499/example/index.js

@@ -0,0 +1,2 @@
+import * as constants from './constants'
+export { constants }

test/cases/side-effects/missing-module-7499/example/package.json

@@ -0,0 +1,3 @@
+{
+  "sideEffects": false
+}

test/cases/side-effects/missing-module-7499/index.js

@@ -0,0 +1,10 @@
+import './example'
+
+it("should run correctly", function() {
+	return import('./lazy').then(lazy => {
+		expect(lazy.default()).toEqual({
+			hello: "world",
+			[Symbol.toStringTag]: "Module"
+		});
+	})
+});

test/cases/side-effects/missing-module-7499/lazy.js

@@ -0,0 +1,5 @@
+import { constants } from './example'
+
+export default function getConstants() {
+	return constants;
+}