michael@0: // for-of on an empty collection does not execute the loop body or modify the loop variable.
michael@0: 
michael@0: function test(empty) {
michael@0:     var x = 'unchanged';
michael@0:     for (x of empty)
michael@0:         throw fit;
michael@0:     assertEq(x, 'unchanged');
michael@0: }
michael@0: 
michael@0: test([]);
michael@0: test(new Map);
michael@0: test(new Set);