This repository demonstrates an issue with Mongo 1.14.1.
Adding a new field to a document, with the following shape
foo: { bar: [1, 2, 3] }results in the published bar array being converted to an object (on the client-side).
This issue occurs if the method is executed just server-side or also if the method is executed client-side. In this example app, the method is a server-side method.
Please run this app using the meteor run command. If you need to reset the database then run meteor reset.
The method that updates the collection is in the main.js file.