mongo/jstests/core/query/array/arrayfindb.js

// Test $elemMatch object with complex embedded expressions.
// @tags: [
//   requires_getmore,
// ]

let t = db.jstests_arrayfindb;
t.drop();

// Case #1: Ensure correct matching for $elemMatch with an embedded $and (SERVER-13664).
t.save({
    a: [
        {b: 1, c: 25},
        {a: 3, b: 59},
    ],
});
assert.eq(
    0,
    t.find({a: {$elemMatch: {b: {$gte: 2, $lt: 4}, c: 25}}}).itcount(),
    "Case #1: wrong number of results returned -- unindexed",
);

t.createIndex({"a.b": 1, "a.c": 1});
assert.eq(
    0,
    t.find({a: {$elemMatch: {b: {$gte: 2, $lt: 4}, c: 25}}}).itcount(),
    "Case #1: wrong number of results returned -- indexed",
);

// Case #2: Ensure correct matching for $elemMatch with an embedded $or.
t.drop();
t.save({a: [{b: 1}, {c: 1}]});
t.save({a: [{b: 2}, {c: 1}]});
t.save({a: [{b: 1}, {c: 2}]});
assert.eq(
    2,
    t.find({a: {$elemMatch: {$or: [{b: 2}, {c: 2}]}}}).itcount(),
    "Case #2: wrong number of results returned -- unindexed",
);

t.createIndex({"a.b": 1});
t.createIndex({"a.c": 1});
assert.eq(
    2,
    t.find({a: {$elemMatch: {$or: [{b: 2}, {c: 2}]}}}).itcount(),
    "Case #2: wrong number of results returned -- indexed",
);