// Test that we can sort on fields, produces by unwind const coll = db.agg_unwind_sort; coll.drop(); assert.commandWorked(coll.insertOne({a: [3, 4, 5]})); assert.commandWorked(coll.insertOne({a: [1, 2]})); let result = coll.aggregate([{$unwind: "$a"}, {$sort: {a: 1}}]).toArray(); assert.eq([1, 2, 3, 4, 5], result.map(function(z) { return z.a; })); result = coll.aggregate([{$unwind: "$a"}, {$sort: {a: -1}}]).toArray(); assert.eq([5, 4, 3, 2, 1], result.map(function(z) { return z.a; })); result = coll.aggregate([{$unwind: {path: "$a", includeArrayIndex: "i"}}, {$sort: {i: 1}}]).toArray(); assert.eq([NumberLong(0), NumberLong(0), NumberLong(1), NumberLong(1), NumberLong(2)], result.map(function(z) { return z.i; })); result = coll.aggregate([{$unwind: {path: "$a", includeArrayIndex: "i"}}, {$sort: {i: -1}}]).toArray(); assert.eq([NumberLong(2), NumberLong(1), NumberLong(1), NumberLong(0), NumberLong(0)], result.map(function(z) { return z.i; }));