rollup/test/form/side-effect-t/_expected/iife.js

(function (exports) {
	'use strict';

	function x () {
		return new Promise( ( resolve, reject ) => {
			console.log( 'this is a side-effect' );
			resolve();
		});
	}

	x();

	function promiseCallback ( resolve, reject ) {
		console.log( 'this is a side-effect' );
		resolve();
	}

	function y () {
		return new Promise( promiseCallback );
	}

	y();

	function z ( x ) {
		// this function has no side-effects, so should be excluded...
	}

	exports.a = 1;
	z( exports.a += 1 ); // ...unless the call expression statement has its own side-effects

}((this.myBundle = this.myBundle || {})));