// test $size
load('jstests/aggregation/extras/utils.js');

c = db.server4899;
c.drop();
c.save({arr: []});
c.save({arr: [1]});
c.save({arr: ["asdf", "asdfasdf"]});
c.save({arr: [1, "asdf", 1234, 4.3, {key: 23}]});
c.save({arr: [3, [31, 31, 13, 13]]});

result = c.aggregate({$project: {_id: 0, length: {$size: "$arr"}}});
assert.eq(result.toArray(), [{length: 0}, {length: 1}, {length: 2}, {length: 5}, {length: 2}]);

c.save({arr: 231});
assertErrorCode(c, {$project: {_id: 0, length: {$size: "$arr"}}}, 17124);