// server9289 - support objects as single arguments to expressions.

let t = db[jsTestName()];
t.drop();

t.insert({date: ISODate("2013-08-14T21:41:43Z")});

// This would result in a parse error on older servers
assert.eq(t.aggregate({$project: {year: {$year: {$add: ["$date", 1000]}}}}).toArray()[0].year, 2013);