python buildscripts/resmoke.py --storageEngine wiredTiger --suites aggregation repro_set_intersection.js repro_set_intersection.js assert.commandWorked(db.my_coll.insert({ a: []})); const res1 = db.my_coll .aggregate([{ $project: { a: { $setIntersection: [ "$a" , "$missing" , ] }, _id: 0, } }]) .toArray(); const res2 = db.my_coll .aggregate([{ $project: { a: { $setIntersection: [ "$missing" , "$a" , ] }, _id: 0, } }]) .toArray(); assert.eq(res1, res2);