dont separate vars in for loop head

src/ast/nodes/VariableDeclaration.js

@@ -15,9 +15,21 @@ function getSeparator ( code, start ) {
 }
 
 export default class VariableDeclaration extends Node {
+	initialise ( scope ) {
+		this.scope = scope;
+		super.initialise( scope );
+	}
+
 	render ( code, es ) {
 		const treeshake = this.module.bundle.treeshake;
-		const separator = this.declarations.length ? getSeparator( this.module.code, this.start ) : '';
+
+		let shouldSeparate = false;
+		let separator;
+
+		if ( this.scope.isModuleScope && !/forStatement/.test( this.parent.type ) ) {
+			shouldSeparate = true;
+			separator = getSeparator( this.module.code, this.start );
+		}
 
 		let c = this.start;
 		let empty = true;
@@ -33,12 +45,12 @@ export default class VariableDeclaration extends Node {
 
 				if ( isExportedAndReassigned ) {
 					if ( declarator.init ) {
-						code.overwrite( c, declarator.start, prefix );
+						if ( shouldSeparate ) code.overwrite( c, declarator.start, prefix );
 						c = declarator.end;
 						empty = false;
 					}
 				} else if ( !treeshake || proxy.activated ) {
-					code.overwrite( c, declarator.start, `${prefix}${this.kind} ` ); // TODO indentation
+					if ( shouldSeparate ) code.overwrite( c, declarator.start, `${prefix}${this.kind} ` ); // TODO indentation
 					c = declarator.end;
 					empty = false;
 				}
@@ -63,7 +75,7 @@ export default class VariableDeclaration extends Node {
 				});
 
 				if ( !treeshake || activated ) {
-					code.overwrite( c, declarator.start, `${prefix}${this.kind} ` ); // TODO indentation
+					if ( shouldSeparate ) code.overwrite( c, declarator.start, `${prefix}${this.kind} ` ); // TODO indentation
 					c = declarator.end;
 					empty = false;
 				}

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

@@ -1,8 +1,7 @@
 define(function () { 'use strict';
 
 	function augment ( x ) {
-		var prop;
-		var source;
+		var prop, source;
 
 		var i = arguments.length;
 		var sources = Array( i - 1 );

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

@@ -1,8 +1,7 @@
 'use strict';
 
 function augment ( x ) {
-	var prop;
-	var source;
+	var prop, source;
 
 	var i = arguments.length;
 	var sources = Array( i - 1 );

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

@@ -1,6 +1,5 @@
 function augment ( x ) {
-	var prop;
-	var source;
+	var prop, source;
 
 	var i = arguments.length;
 	var sources = Array( i - 1 );

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

@@ -2,8 +2,7 @@ var myBundle = (function () {
 	'use strict';
 
 	function augment ( x ) {
-		var prop;
-		var source;
+		var prop, source;
 
 		var i = arguments.length;
 		var sources = Array( i - 1 );

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

@@ -5,8 +5,7 @@
 }(this, (function () { 'use strict';
 
 	function augment ( x ) {
-		var prop;
-		var source;
+		var prop, source;
 
 		var i = arguments.length;
 		var sources = Array( i - 1 );

test/function/vars-in-for-loop-head/_config.js

@@ -0,0 +1,3 @@
+module.exports = {
+	description: 'does not break apart vars in for loop head'
+};

test/function/vars-in-for-loop-head/main.js

@@ -0,0 +1,10 @@
+function clone ( things ) {
+	var result = [];
+	for ( var i = 0, list = things; i < list.length; i += 1 ) {
+		var thing = list[i];
+		result.push( thing );
+	}
+	return result;
+}
+
+assert.deepEqual( clone([ 1, 2, 3 ]), [ 1, 2, 3 ] );