michael@0: function f(arr)
michael@0: {
michael@0:   assertEq(arr.shift(), 0);
michael@0: }
michael@0: 
michael@0: function test(out)
michael@0: {
michael@0:   // Create an array of arrays, to be iterated over for [].shift-calling.  We
michael@0:   // can't just loop on shift on a single array with non-writable length because
michael@0:   // shift throws when called on an array with non-writable length.
michael@0:   var arrs = out.arrs = [];
michael@0:   for (var i = 0; i < 100; i++)
michael@0:     arrs.push([0, 1, 2, 3]);
michael@0: 
michael@0:   // Use a much-greater capacity than the eventual non-writable length.
michael@0:   var a = [0, 1, 2, 3, 4, 5, 6, 7];
michael@0:   Object.defineProperty(a, "length", { writable: false, value: 4 });
michael@0: 
michael@0:   arrs.push(a);
michael@0: 
michael@0:   for (var i = 0, sz = arrs.length; i < sz; i++)
michael@0:   {
michael@0:     var arr = arrs[i];
michael@0:     f(arr);
michael@0:   }
michael@0: }
michael@0: 
michael@0: var obj = {};
michael@0: var a, arrs;
michael@0: 
michael@0: try
michael@0: {
michael@0:   test(obj);
michael@0:   throw new Error("didn't throw!");
michael@0: }
michael@0: catch (e)
michael@0: {
michael@0:   assertEq(e instanceof TypeError, true, "expected TypeError, got " + e);
michael@0: 
michael@0:   arrs = obj.arrs;
michael@0:   assertEq(arrs.length, 101);
michael@0:   for (var i = 0; i < 100; i++)
michael@0:   {
michael@0:     assertEq(arrs[i].length, 3, "unexpected length for arrs[" + i + "]");
michael@0:     assertEq(arrs[i][0], 1, "bad element for arrs[" + i + "][0]");
michael@0:     assertEq(arrs[i][1], 2, "bad element for arrs[" + i + "][1]");
michael@0:     assertEq(arrs[i][2], 3, "bad element for arrs[" + i + "][2]");
michael@0:     assertEq(3 in arrs[i], false, "shouldn't be a third element");
michael@0:     assertEq(arrs[i][3], undefined);
michael@0:   }
michael@0: 
michael@0:   a = arrs[100];
michael@0:   assertEq(a[0], 1, "bad element for a[" + i + "]");
michael@0:   assertEq(a[1], 2, "bad element for a[" + i + "]");
michael@0:   assertEq(a[2], 3, "bad element for a[" + i + "]");
michael@0:   assertEq(a.hasOwnProperty(3), false, "should have been deleted before throw");
michael@0:   assertEq(a[3], undefined);
michael@0:   assertEq(a.length, 4, "length shouldn't have been changed");
michael@0: }