ion-push-nonwritable-length.js

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function f(arr)

  assertEq(arr.push(4), 5); // if it doesn't throw :-)

function test(out)

  // Create an array of arrays, to be iterated over for [].push-calling.  We

  // can't just loop on push on a single array with non-writable length because

  // push throws when called on an array with non-writable length.

  var arrs = out.arrs = [];

  for (var i = 0; i < 100; i++)

    arrs.push([0, 1, 2, 3]);

  // Use a much-greater capacity than the eventual non-writable length, so that

  // the inline-push will work.

  var a = [0, 1, 2, 3, 4, 5, 6, 7];

  Object.defineProperty(a, "length", { writable: false, value: 4 });

  arrs.push(a);

  for (var i = 0, sz = arrs.length; i < sz; i++)

    var arr = arrs[i];

    f(arr);

var obj = {};

var a, arrs;

try

  test(obj);

  throw new Error("didn't throw!");

catch (e)

  assertEq(e instanceof TypeError, true, "expected TypeError, got " + e);

  arrs = obj.arrs;

  assertEq(arrs.length, 101);

  for (var i = 0; i < 100; i++)

    assertEq(arrs[i].length, 5, "unexpected length for arrs[" + i + "]");

    assertEq(arrs[i][0], 0, "bad element for arrs[" + i + "][0]");

    assertEq(arrs[i][1], 1, "bad element for arrs[" + i + "][1]");

    assertEq(arrs[i][2], 2, "bad element for arrs[" + i + "][2]");

    assertEq(arrs[i][3], 3, "bad element for arrs[" + i + "][3]");

    assertEq(arrs[i][4], 4, "bad element for arrs[" + i + "][4]");

  a = arrs[100];

  assertEq(a[0], 0, "bad element for a[" + i + "]");

  assertEq(a[1], 1, "bad element for a[" + i + "]");

  assertEq(a[2], 2, "bad element for a[" + i + "]");

  assertEq(a[3], 3, "bad element for a[" + i + "]");

  assertEq(a.hasOwnProperty(4), false, "element addition should have thrown");

  assertEq(a[4], undefined);

  assertEq(a.length, 4, "length shouldn't have been changed");