dont undo hasSideEffects

src/utils/testForSideEffects.js

@@ -38,7 +38,7 @@ export default function testForSideEffects ( node, scope, statement, strongDepen
 			else if ( node.type === 'ThrowStatement' ) {
 				// we only care about errors thrown at the top level, otherwise
 				// any function with error checking gets included if called
-				hasSideEffect = scope.isTopLevel;
+				if ( scope.isTopLevel ) hasSideEffect = true;
 			}
 
 			else if ( node.type === 'CallExpression' || node.type === 'NewExpression' ) {
@@ -86,7 +86,7 @@ export default function testForSideEffects ( node, scope, statement, strongDepen
 				let declaration = scope.findDeclaration( subject.name );
 
 				if ( declaration ) {
-					hasSideEffect = declaration.isParam;
+					if ( declaration.isParam ) hasSideEffect = true;
 				} else {
 					declaration = statement.module.trace( subject.name );
 

test/form/side-effect-k/_expected/amd.js

@@ -1,5 +1,28 @@
 define(function () { 'use strict';
 
-	
+	function augment ( x ) {
+		var prop, source;
 
-});
+		var i = arguments.length;
+		var sources = Array( i - 1 );
+		while ( i-- ) {
+			sources[i-1] = arguments[i];
+		}
+
+		while (source = sources.shift()) {
+			for (prop in source) {
+				if (hasOwn.call(source, prop)) {
+					x[prop] = source[prop];
+				}
+			}
+		}
+
+		return x;
+	}
+
+	function x () {}
+	augment( x.prototype );
+
+	return x;
+
+});

test/form/side-effect-k/_expected/cjs.js

@@ -1 +1,26 @@
 'use strict';
+
+function augment ( x ) {
+	var prop, source;
+
+	var i = arguments.length;
+	var sources = Array( i - 1 );
+	while ( i-- ) {
+		sources[i-1] = arguments[i];
+	}
+
+	while (source = sources.shift()) {
+		for (prop in source) {
+			if (hasOwn.call(source, prop)) {
+				x[prop] = source[prop];
+			}
+		}
+	}
+
+	return x;
+}
+
+function x () {}
+augment( x.prototype );
+
+module.exports = x;

test/form/side-effect-k/_expected/es6.js

@@ -0,0 +1,24 @@
+function augment ( x ) {
+	var prop, source;
+
+	var i = arguments.length;
+	var sources = Array( i - 1 );
+	while ( i-- ) {
+		sources[i-1] = arguments[i];
+	}
+
+	while (source = sources.shift()) {
+		for (prop in source) {
+			if (hasOwn.call(source, prop)) {
+				x[prop] = source[prop];
+			}
+		}
+	}
+
+	return x;
+}
+
+function x () {}
+augment( x.prototype );
+
+export default x;

test/form/side-effect-k/_expected/iife.js

@@ -0,0 +1,28 @@
+var myBundle = (function () { 'use strict';
+
+	function augment ( x ) {
+		var prop, source;
+
+		var i = arguments.length;
+		var sources = Array( i - 1 );
+		while ( i-- ) {
+			sources[i-1] = arguments[i];
+		}
+
+		while (source = sources.shift()) {
+			for (prop in source) {
+				if (hasOwn.call(source, prop)) {
+					x[prop] = source[prop];
+				}
+			}
+		}
+
+		return x;
+	}
+
+	function x () {}
+	augment( x.prototype );
+
+	return x;
+
+})();

test/form/side-effect-k/_expected/umd.js

@@ -0,0 +1,32 @@
+(function (global, factory) {
+	typeof exports === 'object' && typeof module !== 'undefined' ? module.exports = factory() :
+	typeof define === 'function' && define.amd ? define(factory) :
+	global.myBundle = factory();
+}(this, function () { 'use strict';
+
+	function augment ( x ) {
+		var prop, source;
+
+		var i = arguments.length;
+		var sources = Array( i - 1 );
+		while ( i-- ) {
+			sources[i-1] = arguments[i];
+		}
+
+		while (source = sources.shift()) {
+			for (prop in source) {
+				if (hasOwn.call(source, prop)) {
+					x[prop] = source[prop];
+				}
+			}
+		}
+
+		return x;
+	}
+
+	function x () {}
+	augment( x.prototype );
+
+	return x;
+
+}));