Merge pull request #12452 from webpack/bugfix/12044

lib/javascript/JavascriptParser.js

@@ -2625,21 +2625,28 @@ class JavascriptParser extends Parser {
 	}
 
 	walkCallExpression(expression) {
+		const isSimpleFunction = fn => {
+			return fn.params.every(p => p.type === "Identifier");
+		};
 		if (
 			expression.callee.type === "MemberExpression" &&
 			expression.callee.object.type.endsWith("FunctionExpression") &&
 			!expression.callee.computed &&
 			(expression.callee.property.name === "call" ||
 				expression.callee.property.name === "bind") &&
-			expression.arguments.length > 0
+			expression.arguments.length > 0 &&
+			isSimpleFunction(expression.callee.object)
 		) {
 			// (function(…) { }.call/bind(?, …))
 			this._walkIIFE(
 				expression.callee.object,
 				expression.arguments.slice(1),
 				expression.arguments[0]
 			);
-		} else if (expression.callee.type.endsWith("FunctionExpression")) {
+		} else if (
+			expression.callee.type.endsWith("FunctionExpression") &&
+			isSimpleFunction(expression.callee)
+		) {
 			// (function(…) { }(…))
 			this._walkIIFE(expression.callee, expression.arguments, null);
 		} else {

test/cases/parsing/iife/a.js

@@ -0,0 +1,4 @@
+export let a = 1e3;
+
+export function b() { a = 1e2 }
+export function c() { a = 1e1 }

test/cases/parsing/iife/index.js

@@ -0,0 +1,10 @@
+import { a } from './a';
+import { track1, track2 } from './side-effect-call';
+
+it("should parse params", () => {
+	expect(a).toBe(1000);
+	track1();
+	expect(a).toBe(100);
+	track2();
+	expect(a).toBe(10);
+});

test/cases/parsing/iife/side-effect-call.js

@@ -0,0 +1,9 @@
+import { b, c } from './a'
+
+export function track1() {
+	(function (a = b()) {})()
+}
+
+export function track2() {
+	((a = c()) => {})()
+}

test/cases/parsing/iife/test.filter.js

@@ -0,0 +1,4 @@
+module.exports = function (config) {
+	// TODO fails due to minimizer bug: https://github.com/terser/terser/issues/880
+	return !config.minimize;
+};