michael@0: 
michael@0: function testOverwritingSparseHole()
michael@0: {
michael@0:   var x = [];
michael@0:   for (var i = 0; i < 50; i++)
michael@0:     x[i] = i;
michael@0:   var hit = false;
michael@0:   Object.defineProperty(x, 40, {set: function() { hit = true; }});
michael@0:   for (var i = 0; i < 50; i++)
michael@0:     x[i] = 10;
michael@0:   assertEq(hit, true);
michael@0: }
michael@0: testOverwritingSparseHole();
michael@0: 
michael@0: function testReadingSparseHole()
michael@0: {
michael@0:   var x = [];
michael@0:   for (var i = 5; i < 50; i++)
michael@0:     x[i] = i;
michael@0:   var hit = false;
michael@0:   Object.defineProperty(x, 40, {get: function() { hit = true; return 5.5; }});
michael@0:   var res = 0;
michael@0:   for (var i = 0; i < 50; i++) {
michael@0:     res += x[i];
michael@0:     if (i == 10)
michael@0:       res = 0;
michael@0:   }
michael@0:   assertEq(res, 1135.5);
michael@0:   assertEq(hit, true);
michael@0: }
michael@0: testReadingSparseHole();
michael@0: 
michael@0: function testInSparseHole()
michael@0: {
michael@0:   var x = [];
michael@0:   for (var i = 5; i < 50; i++)
michael@0:     x[i] = i;
michael@0:   Object.defineProperty(x, 40, {get: function() {}});
michael@0:   var res = 0;
michael@0:   for (var i = 0; i < 50; i++)
michael@0:     res += (i in x) ? 1 : 0;
michael@0:   assertEq(res, 45);
michael@0: }
michael@0: testInSparseHole();