count the number of documents of each movie in the list

I want to count the number of documents of each movie in the MotherCard collection:

const list = ['Frozen 2013', 'Oblivion 2013', 'Avatar 2009'];

const count = await db.MotherCard.countDocuments({ movie: { $in: list }});  

console.log(count)

But it only returns the number of documents of the first array element (‘Frozen 2013’).

How can we count documents count of all of the list ?

>Solution :

I think this can be implemented using MongoDB’s aggregation pipeline.  

const list = ['Frozen 2013', 'Oblivion 2013', 'Avatar 2009'];

const result = await db.MotherCard.aggregate([
    { $match: { movie: { $in: list }}},
    { $group: { _id: "$movie", count: { $sum: 1 }}}
]).exec();

console.log(result);

and the result will look like this:

[
    { "_id" : "Frozen 2013", "count" : 10 },
    { "_id" : "Oblivion 2013", "count" : 10 },
    { "_id" : "Avatar 2009", "count" : 10 }
]