v8/test/mjsunit/array-sort.js

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// Flags: --allow-natives-syntax

// Test array sort.

// Test counter-intuitive default number sorting.
function TestNumberSort() {
  var a = [ 200, 45, 7 ];

  // Default sort converts each element to string and orders
  // lexicographically.
  a.sort();
  assertArrayEquals([ 200, 45, 7 ], a);
  // Sort numbers by value using a compare functions.
  a.sort(function(x, y) { return x - y; });
  assertArrayEquals([ 7, 45, 200 ], a);

  // Default sort on negative numbers.
  a = [-12345,-123,-1234,-123456];
  a.sort();
  assertArrayEquals([-123,-1234,-12345,-123456], a);

  // Default sort on negative and non-negative numbers.
  a = [123456,0,-12345,-123,123,1234,-1234,0,12345,-123456];
  a.sort();
  assertArrayEquals([-123,-1234,-12345,-123456,0,0,123,1234,12345,123456], a);

  // Tricky case avoiding integer overflow in Runtime_SmiLexicographicCompare.
  a = [9, 1000000000].sort();
  assertArrayEquals([1000000000, 9], a);
  a = [1000000000, 1].sort();
  assertArrayEquals([1, 1000000000], a);
  a = [1000000000, 0].sort();
  assertArrayEquals([0, 1000000000], a);

  // One string is a prefix of the other.
  a = [1230, 123].sort();
  assertArrayEquals([123, 1230], a);
  a = [1231, 123].sort();
  assertArrayEquals([123, 1231], a);

  // Default sort on Smis and non-Smis.
  a = [1000000000, 10000000000, 1000000001, -1000000000, -10000000000, -1000000001];
  a.sort();
  assertArrayEquals([-1000000000, -10000000000, -1000000001, 1000000000, 10000000000, 1000000001], a);

  // Other cases are tested implicitly in TestSmiLexicographicCompare.
}

TestNumberSort();

function TestSmiLexicographicCompare() {

  assertFalse(%_IsSmi(2147483648), 'Update test for >32 bit Smi');

  // Collect a list of interesting Smis.
  var seen = {};
  var smis = [];
  function add(x) {
    if (x | 0 == x) {
      x = x | 0;  // Canonicalizes to Smi if 32-bit signed and fits in Smi.
    }
    if (%_IsSmi(x) && !seen[x]) {
      seen[x] = 1;
      smis.push(x);
    }
  }
  function addSigned(x) {
    add(x);
    add(-x);
  }

  var BIGGER_THAN_ANY_SMI = 10 * 1000 * 1000 * 1000;
  for (var xb = 1; xb <= BIGGER_THAN_ANY_SMI; xb *= 10) {
    for (var xf = 0; xf <= 9; xf++) {
      for (var xo = -1; xo <= 1; xo++) {
        addSigned(xb * xf + xo);
      }
    }
  }

  for (var yb = 1; yb <= BIGGER_THAN_ANY_SMI; yb *= 2) {
    for (var yo = -2; yo <= 2; yo++) {
      addSigned(yb + yo);
    }
  }

  for (var i = 0; i < smis.length; i++) {
    for (var j = 0; j < smis.length; j++) {
      var x = smis[i];
      var y = smis[j];
      var lex = %SmiLexicographicCompare(x, y);
      var expected = (x == y) ? 0 : ((x + "") < (y + "") ? -1 : 1);
      assertEquals(lex, expected, x + " < " + y);
    }
  }
}

TestSmiLexicographicCompare();


// Test lexicographical string sorting.
function TestStringSort() {
  var a = [ "cc", "c", "aa", "a", "bb", "b", "ab", "ac" ];
  a.sort();
  assertArrayEquals([ "a", "aa", "ab", "ac", "b", "bb", "c", "cc" ], a);
}

TestStringSort();


// Test object sorting.  Calls toString on each element and sorts
// lexicographically.
function TestObjectSort() {
  var obj0 = { toString: function() { return "a"; } };
  var obj1 = { toString: function() { return "b"; } };
  var obj2 = { toString: function() { return "c"; } };
  var a = [ obj2, obj0, obj1 ];
  a.sort();
  assertArrayEquals([ obj0, obj1, obj2 ], a);
}

TestObjectSort();

// Test array sorting with holes in the array.
function TestArraySortingWithHoles() {
  var a = [];
  a[4] = "18";
  a[10] = "12";
  a.sort();
  assertEquals(11, a.length);
  assertEquals("12", a[0]);
  assertEquals("18", a[1]);
}

TestArraySortingWithHoles();

// Test array sorting with undefined elemeents in the array.
function TestArraySortingWithUndefined() {
  var a = [ 3, void 0, 2 ];
  a.sort();
  assertArrayEquals([ 2, 3, void 0 ], a);
}

TestArraySortingWithUndefined();

// Test that sorting using an unsound comparison function still gives a
// sane result, i.e. it terminates without error and retains the elements
// in the array.
function TestArraySortingWithUnsoundComparisonFunction() {
  var a = [ 3, void 0, 2 ];
  a.sort(function(x, y) { return 1; });
  a.sort();
  assertArrayEquals([ 2, 3, void 0 ], a);
}

TestArraySortingWithUnsoundComparisonFunction();


function TestSparseNonArraySorting(length) {
  assertTrue(length > 101);
  var obj = {length: length};
  obj[0] = 42;
  obj[10] = 37;
  obj[100] = undefined;
  obj[length - 1] = null;
  Array.prototype.sort.call(obj);
  assertEquals(length, obj.length, "objsort length unaffected");
  assertEquals(37, obj[0], "objsort smallest number");
  assertEquals(42, obj[1], "objsort largest number");
  assertEquals(null, obj[2], "objsort null");
  assertEquals(undefined, obj[3], "objsort undefined");
  assertTrue(3 in obj, "objsort undefined retained");
  assertFalse(4 in obj, "objsort non-existing retained");
}

TestSparseNonArraySorting(5000);
TestSparseNonArraySorting(500000);
TestSparseNonArraySorting(Math.pow(2, 31) + 1);


function TestArrayLongerLength(length) {
  var x = new Array(4);
  x[0] = 42;
  x[2] = 37;
  x.length = length;
  Array.prototype.sort.call(x);
  assertEquals(length, x.length, "longlength length");
  assertEquals(37, x[0], "longlength first");
  assertEquals(42, x[1], "longlength second");
  assertFalse(2 in x,"longlength third");
}

TestArrayLongerLength(4);
TestArrayLongerLength(10);
TestArrayLongerLength(1000);
TestArrayLongerLength(500000);
TestArrayLongerLength(Math.pow(2,32) - 1);


function TestNonArrayLongerLength(length) {
  var x = {};
  x[0] = 42;
  x[2] = 37;
  x.length = length;
  Array.prototype.sort.call(x);
  assertEquals(length, x.length, "longlength length");
  assertEquals(37, x[0], "longlength first");
  assertEquals(42, x[1], "longlength second");
  assertFalse(2 in x,"longlength third");
}

TestNonArrayLongerLength(4);
TestNonArrayLongerLength(10);
TestNonArrayLongerLength(1000);
TestNonArrayLongerLength(500000);
TestNonArrayLongerLength(Math.pow(2,32) - 1);


function TestNonArrayWithAccessors() {
  // Regression test for issue 346, more info at URL
  // http://code.google.com/p/v8/issues/detail?id=346
  // Reported by nth10sd, test based on this report.
  var x = {};
  x[0] = 42;
  x.__defineGetter__("1", function(){return this.foo;});
  x.__defineSetter__("1", function(val){this.foo = val;});
  x[1] = 49
  x[3] = 37;
  x.length = 4;
  Array.prototype.sort.call(x);
  // Behavior of sort with accessors is undefined.  This accessor is
  // well-behaved (acts like a normal property), so it should work.
  assertEquals(4, x.length, "sortaccessors length");
  assertEquals(37, x[0], "sortaccessors first");
  assertEquals(42, x[1], "sortaccessors second");
  assertEquals(49, x[2], "sortaccessors third")
  assertFalse(3 in x, "sortaccessors fourth");
}

TestNonArrayWithAccessors();


function TestInheritedElementSort(depth) {
  var length = depth * 2 + 3;
  var obj = {length: length};
  obj[depth * 2 + 1] = 0;
  for (var i = 0; i < depth; i++) {
    var newObj = {};
    newObj.__proto__ = obj;
    obj[i] = undefined;
    obj[i + depth + 1] = depth - i;
    obj = newObj;
  }
  // expected (inherited) object: [undef1,...undefdepth,hole,1,...,depth,0,hole]

  Array.prototype.sort.call(obj, function(a,b) { return (b < a) - (a < b); });
  // expected result: [0,1,...,depth,undef1,...,undefdepth,undef,hole]
  var name = "SortInherit("+depth+")-";

  assertEquals(length, obj.length, name+"length");
  for (var i = 0; i <= depth; i++) {
    assertTrue(obj.hasOwnProperty(i), name + "hasvalue" + i);
    assertEquals(i, obj[i], name + "value" + i);
  }
  for (var i = depth + 1; i <= depth * 2 + 1; i++) {
    assertEquals(undefined, obj[i], name + "undefined" + i);
    assertTrue(obj.hasOwnProperty(i), name + "hasundefined" + i);
  }
  assertTrue(!obj.hasOwnProperty(depth * 2 + 2), name + "hashole");
}

TestInheritedElementSort(5);
TestInheritedElementSort(15);

function TestSparseInheritedElementSort(scale) {
  var length = scale * 10;
  var x = {length: length};
  var y = {};
  y.__proto__ = x;

  for (var i = 0; i < 5; i++) {
    x[i * 2 * scale] = 2 * (4 - i);
    y[(i * 2 + 1) * scale] = 2 * (4 - i) + 1;
  }

  var name = "SparseSortInherit(" + scale + ")-";

  Array.prototype.sort.call(y);

  assertEquals(length, y.length, name +"length");

  for (var i = 0; i < 10; i++) {
    assertTrue(y.hasOwnProperty(i), name + "hasvalue" + i);
    assertEquals(i, y[i], name + "value" + i);
  }
  for (var i = 10; i < length; i++) {
    assertEquals(x.hasOwnProperty(i), y.hasOwnProperty(i),
                 name + "hasundef" + i);
    assertEquals(undefined, y[i], name+"undefined"+i);
    if (x.hasOwnProperty(i)) {
      assertTrue(0 == i % (2 * scale), name + "new_x" + i);
    }
  }
}

TestSparseInheritedElementSort(10);
TestSparseInheritedElementSort(100);
TestSparseInheritedElementSort(1000);

function TestSpecialCasesInheritedElementSort() {

  var x = {
    1:"d1",
    2:"c1",
    3:"b1",
    4: undefined,
    __proto__: {
      length: 10000,
      1: "e2",
      10: "a2",
      100: "b2",
      1000: "c2",
      2000: undefined,
      8000: "d2",
      12000: "XX",
      __proto__: {
        0: "e3",
        1: "d3",
        2: "c3",
        3: "b3",
        4: "f3",
        5: "a3",
        6: undefined,
      }
    }
  };
  Array.prototype.sort.call(x);

  var name = "SpecialInherit-";

  assertEquals(10000, x.length, name + "length");
  var sorted = ["a2", "a3", "b1", "b2", "c1", "c2", "d1", "d2", "e3",
                undefined, undefined, undefined];
  for (var i = 0; i < sorted.length; i++) {
    assertTrue(x.hasOwnProperty(i), name + "has" + i)
    assertEquals(sorted[i], x[i], name + i);
  }
  assertFalse(x.hasOwnProperty(sorted.length), name + "haspost");
  assertFalse(sorted.length in x, name + "haspost2");
  assertTrue(x.hasOwnProperty(10), name + "hasundefined10");
  assertEquals(undefined, x[10], name + "undefined10");
  assertTrue(x.hasOwnProperty(100), name + "hasundefined100");
  assertEquals(undefined, x[100], name + "undefined100");
  assertTrue(x.hasOwnProperty(1000), name + "hasundefined1000");
  assertEquals(undefined, x[1000], name + "undefined1000");
  assertTrue(x.hasOwnProperty(2000), name + "hasundefined2000");
  assertEquals(undefined, x[2000], name + "undefined2000");
  assertTrue(x.hasOwnProperty(8000), name + "hasundefined8000");
  assertEquals(undefined, x[8000], name + "undefined8000");
  assertFalse(x.hasOwnProperty(12000), name + "has12000");
  assertEquals("XX", x[12000], name + "XX12000");
}

TestSpecialCasesInheritedElementSort();

// Test that sort calls compare function with global object as receiver,
// and with only elements of the array as arguments.
function o(v) {
  return {__proto__: o.prototype, val: v};
}
var arr = [o(1), o(2), o(4), o(8), o(16), o(32), o(64), o(128), o(256), o(-0)];
var global = this;
function cmpTest(a, b) {
  assertEquals(global, this);
  assertTrue(a instanceof o);
  assertTrue(b instanceof o);
  return a.val - b.val;
}
arr.sort(cmpTest);

function TestSortDoesNotDependOnObjectPrototypeHasOwnProperty() {
  Array.prototype.sort.call({
    __proto__: { hasOwnProperty: null, 0: 1 },
    length: 5
  });

  var arr = new Array(2);
  Object.defineProperty(arr, 0, { get: function() {}, set: function() {} });
  arr.hasOwnProperty = null;
  arr.sort();
}

TestSortDoesNotDependOnObjectPrototypeHasOwnProperty();

function TestSortDoesNotDependOnArrayPrototypePush() {
  // InsertionSort is used for arrays which length <= 22
  var arr = [];
  for (var i = 0; i < 22; i++) arr[i] = {};
  Array.prototype.push = function() {
    fail('Should not call push');
  };
  arr.sort();

  // Quicksort is used for arrays which length > 22
  // Arrays which length > 1000 guarantee GetThirdIndex is executed
  arr = [];
  for (var i = 0; i < 2000; ++i) arr[i] = {};
  arr.sort();
}

TestSortDoesNotDependOnArrayPrototypePush();

function TestSortDoesNotDependOnArrayPrototypeSort() {
  var arr = [];
  for (var i = 0; i < 2000; i++) arr[i] = {};
  var sortfn = Array.prototype.sort;
  Array.prototype.sort = function() {
    fail('Should not call sort');
  };
  sortfn.call(arr);
  // Restore for the next test
  Array.prototype.sort = sortfn;
}

TestSortDoesNotDependOnArrayPrototypeSort();

function TestSortToObject() {
  Number.prototype[0] = 5;
  Number.prototype[1] = 4;
  Number.prototype.length = 2;
  x = new Number(0);
  assertEquals(0, Number(Array.prototype.sort.call(x)));
  assertEquals(4, x[0]);
  assertEquals(5, x[1]);
  assertArrayEquals(["0", "1"], Object.getOwnPropertyNames(x));
  // The following would throw if ToObject weren't called.
  assertEquals(0, Number(Array.prototype.sort.call(0)));
}
TestSortToObject();