mongo-aggregator

npm i mongo-aggregator

Usage:

var expander = require('mongo-aggregator');
There are three methods:

expander.expandOne(childPath, projection, [childCollectionName])
 for expand simple (not array) field.

expander.expandMany(childPath, projection, [childCollectionName])
 for expand array field.

expander.expandManyWithChildProjection =
 function (childPathName, projection, childProjection, childCollectionName)
 for expand array field with projection for child documents.
 A result of functions will be aggregation obj.
 Next:
 // mongoose
 MyModel.aggregate(aggregationObj, function(err, myModels) {
 ...

 });
 // or mongo driver
 db.collection('myCollection').aggregate(aggregationObj, function(err, myDocs) {
 ...

 });

    Projection example:
    {
        name: 1,
        age: 1
    }

    For running tests install mocha globally before: npm i mocha -g
    And: npm run test