push-slowly-loopy-nonwritable-length.js (1375B)
1 load(libdir + "asserts.js"); 2 3 function f(arr, v1, v2) 4 { 5 // Ensure array_push_slowly is called by passing more than one argument. 6 arr.push(v1, v2); 7 } 8 9 var N = 100; 10 11 function test(out) 12 { 13 // Create an array of arrays, to be iterated over for [].push-calling. We 14 // can't just loop on push on a single array with non-writable length because 15 // push throws when called on an array with non-writable length. 16 var arrs = out.arrs = []; 17 for (var i = 0; i < N; i++) 18 arrs.push([]); 19 20 // Use a much-greater capacity than the eventual non-writable length. 21 var a = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15]; 22 Object.defineProperty(a, "length", { writable: false, value: 6 }); 23 24 arrs.push(a); 25 26 for (var i = 0, sz = arrs.length; i < sz; i++) 27 { 28 var arr = arrs[i]; 29 f(arr, 8675309, 3141592); 30 } 31 } 32 33 var obj = {}; 34 35 assertThrowsInstanceOf(function() { test(obj); }, TypeError); 36 37 var arrs = obj.arrs; 38 assertEq(arrs.length, N + 1); 39 for (var i = 0; i < N; i++) 40 { 41 assertEq(arrs[i].length, 2, "unexpected length for arrs[" + i + "]"); 42 assertEq(arrs[i][0], 8675309, "bad element for arrs[" + i + "][0]"); 43 assertEq(arrs[i][1], 3141592, "bad element for arrs[" + i + "][1]"); 44 } 45 46 var a = arrs[N]; 47 assertEq(a.hasOwnProperty(6), false); 48 assertEq(a[6], undefined); 49 assertEq(a.hasOwnProperty(7), false); 50 assertEq(a[7], undefined); 51 assertEq(a.length, 6);