ion-pop-nonwritable-length.js (1384B)
1 load(libdir + "asserts.js"); 2 3 function f(arr) 4 { 5 arr.pop(); 6 } 7 8 var N = 100; 9 10 function test(out) 11 { 12 // Create an array of arrays, to be iterated over for [].pop-calling. We 13 // can't just loop on pop on a single array with non-writable length because 14 // pop throws when called on an array with non-writable length. 15 var arrs = out.arrs = []; 16 for (var i = 0; i < N; i++) 17 arrs.push([0, 1, 2, 3]); 18 19 // Use a much-greater capacity than the eventual non-writable length. 20 var a = [0, 1, 2, 3, 4, 5, 6, 7]; 21 Object.defineProperty(a, "length", { writable: false, value: 4 }); 22 23 arrs.push(a); 24 25 for (var i = 0, sz = arrs.length; i < sz; i++) 26 f(arrs[i]); 27 } 28 29 var obj = {}; 30 31 assertThrowsInstanceOf(function() { test(obj); }, TypeError); 32 33 var arrs = obj.arrs; 34 assertEq(arrs.length, N + 1); 35 for (var i = 0; i < N; i++) 36 { 37 assertEq(arrs[i].length, 3, "unexpected length for arrs[" + i + "]"); 38 assertEq(arrs[i][0], 0, "bad element for arrs[" + i + "][0]"); 39 assertEq(arrs[i][1], 1, "bad element for arrs[" + i + "][1]"); 40 assertEq(arrs[i][2], 2, "bad element for arrs[" + i + "][2]"); 41 assertEq(3 in arrs[i], false, "shouldn't be a third element"); 42 assertEq(arrs[i][3], undefined); 43 } 44 45 var a = arrs[N]; 46 assertEq(a.hasOwnProperty(3), false, "should have been deleted before throw"); 47 assertEq(a[3], undefined); 48 assertEq(a.length, 4, "length shouldn't have been changed");