ion-push-nonwritable-length.js (1814B)
1 function f(arr) 2 { 3 assertEq(arr.push(4), 5); // if it doesn't throw :-) 4 } 5 6 function test(out) 7 { 8 // Create an array of arrays, to be iterated over for [].push-calling. We 9 // can't just loop on push on a single array with non-writable length because 10 // push throws when called on an array with non-writable length. 11 var arrs = out.arrs = []; 12 for (var i = 0; i < 100; i++) 13 arrs.push([0, 1, 2, 3]); 14 15 // Use a much-greater capacity than the eventual non-writable length, so that 16 // the inline-push will work. 17 var a = [0, 1, 2, 3, 4, 5, 6, 7]; 18 Object.defineProperty(a, "length", { writable: false, value: 4 }); 19 20 arrs.push(a); 21 22 for (var i = 0, sz = arrs.length; i < sz; i++) 23 { 24 var arr = arrs[i]; 25 f(arr); 26 } 27 } 28 29 var obj = {}; 30 var a, arrs; 31 32 try 33 { 34 test(obj); 35 throw new Error("didn't throw!"); 36 } 37 catch (e) 38 { 39 assertEq(e instanceof TypeError, true, "expected TypeError, got " + e); 40 41 arrs = obj.arrs; 42 assertEq(arrs.length, 101); 43 for (var i = 0; i < 100; i++) 44 { 45 assertEq(arrs[i].length, 5, "unexpected length for arrs[" + i + "]"); 46 assertEq(arrs[i][0], 0, "bad element for arrs[" + i + "][0]"); 47 assertEq(arrs[i][1], 1, "bad element for arrs[" + i + "][1]"); 48 assertEq(arrs[i][2], 2, "bad element for arrs[" + i + "][2]"); 49 assertEq(arrs[i][3], 3, "bad element for arrs[" + i + "][3]"); 50 assertEq(arrs[i][4], 4, "bad element for arrs[" + i + "][4]"); 51 } 52 53 a = arrs[100]; 54 assertEq(a[0], 0, "bad element for a[" + i + "]"); 55 assertEq(a[1], 1, "bad element for a[" + i + "]"); 56 assertEq(a[2], 2, "bad element for a[" + i + "]"); 57 assertEq(a[3], 3, "bad element for a[" + i + "]"); 58 assertEq(a.hasOwnProperty(4), false, "element addition should have thrown"); 59 assertEq(a[4], undefined); 60 assertEq(a.length, 4, "length shouldn't have been changed"); 61 }