src/third_party/mozjs-45/js/src/jit-test/tests/basic/typed-array-sealed-frozen.js

// Any copyright is dedicated to the Public Domain.
// http://creativecommons.org/licenses/publicdomain/

load(libdir + "asserts.js")

const constructors = [
  Int8Array,
  Uint8Array,
  Uint8ClampedArray,
  Int16Array,
  Uint16Array,
  Int32Array,
  Uint32Array,
  Float32Array,
  Float64Array
];

for (constructor of constructors) {
  print("testing non-empty " + constructor.name);
  let a = new constructor(10);
  assertEq(Object.isExtensible(a), true);
  assertEq(Object.isSealed(a), false);
  assertEq(Object.isFrozen(a), false);

  // Should not throw.
  Object.seal(a);

  // Should complain that it can't change attributes of indexed typed array properties.
  assertThrowsInstanceOf(() => Object.freeze(a), TypeError);
}

print();

for (constructor of constructors) {
  print("testing zero-length " + constructor.name);
  let a = new constructor(0);
  assertEq(Object.isExtensible(a), true);
  assertEq(Object.isSealed(a), false);
  assertEq(Object.isFrozen(a), false);

  // Should not throw.
  Object.seal(a);
  Object.freeze(a);
}

// isSealed and isFrozen should not try to build an array of all the
// property names of a typed array, since they're often especially large.
// This should not throw an allocation error.
let a = new Uint8Array(1 << 24);
Object.isSealed(a);
Object.isFrozen(a);

for (constructor of constructors) {
  print("testing extensibility " + constructor.name);
  let a = new constructor(10);

  // New named properties should show up on typed arrays.
  a.foo = "twelve";
  assertEq(a.foo, "twelve");

  // New indexed properties should not show up on typed arrays.
  a[20] = "twelve";
  assertEq(a[20], undefined);

  // Watch for especially large indexed properties.
  a[-10 >>> 0] = "twelve";
  assertEq(a[-10 >>> 0], undefined);

  // Watch for really large indexed properties too.
  a[Math.pow(2, 53)] = "twelve";
  assertEq(a[Math.pow(2, 53)], undefined);

  // Don't define old properties.
  Object.defineProperty(a, 5, {value: 3});
  assertEq(a[5], 3);

  // Don't define new properties.
  Object.defineProperty(a, 20, {value: 3});
  assertEq(a[20], undefined);

  // Don't delete indexed properties.
  a[3] = 3;
  delete a[3];
  assertEq(a[3], 3);
}