splice-nonwritable-length.js (1696B)
1 load(libdir + "asserts.js"); 2 3 function f(arr) 4 { 5 assertEq(arr.splice(1, 2, 9, 8, 7, 6).length, 2); // if it doesn't throw :-) 6 } 7 8 var N = 100; 9 10 function test(out) 11 { 12 // Create an array of arrays, to be iterated over for [].splice-calling. 13 var arrs = out.arrs = []; 14 for (var i = 0; i < N; i++) 15 arrs.push([0, 1, 2, 3]); 16 17 // Use a much-greater capacity than the eventual non-writable length, just for 18 // variability. 19 var a = [0, 1, 2, 3, 4, 5, 6, 7]; 20 Object.defineProperty(a, "length", { writable: false, value: 4 }); 21 22 arrs.push(a); 23 24 for (var i = 0, sz = arrs.length; i < sz; i++) 25 f(arrs[i]); 26 } 27 28 var obj = {}; 29 assertThrowsInstanceOf(function() { test(obj); }, TypeError); 30 31 var arrs = obj.arrs; 32 assertEq(arrs.length, N + 1); 33 for (var i = 0; i < N; i++) 34 { 35 assertEq(arrs[i].length, 6, "unexpected length for arrs[" + i + "]"); 36 assertEq(arrs[i][0], 0, "bad element for arrs[" + i + "][0]"); 37 assertEq(arrs[i][1], 9, "bad element for arrs[" + i + "][1]"); 38 assertEq(arrs[i][2], 8, "bad element for arrs[" + i + "][2]"); 39 assertEq(arrs[i][3], 7, "bad element for arrs[" + i + "][3]"); 40 assertEq(arrs[i][4], 6, "bad element for arrs[" + i + "][4]"); 41 assertEq(arrs[i][5], 3, "bad element for arrs[" + i + "][5]"); 42 } 43 44 var a = arrs[N]; 45 assertEq(a[0], 0, "bad element for a[0]"); 46 assertEq(a[1], 1, "bad element for a[1]"); 47 assertEq(a[2], 2, "bad element for a[2]"); 48 assertEq(a[3], 3, "bad element for a[3]"); 49 assertEq(a.hasOwnProperty(4), false, "shouldn't have added any elements"); 50 assertEq(a[4], undefined); 51 assertEq(a.hasOwnProperty(5), false, "shouldn't have added any elements"); 52 assertEq(a[5], undefined); 53 assertEq(a.length, 4, "length shouldn't have been changed");