Subscription Test

This repository is a demonstration that simultaneous subscriptions with different mongo projections for nested fields can lead to unexpected data.

Each item in the Bikes collection has the following structure:

{
  "_id": "_id_",
  "type": "Type",
  "gears": {
    "front": "54",
    "rear": "16"
  },
  "color": "Color"
}

1. The List

A list of all bike records is shown. This list has the following subscription with field projection:

Meteor.subscribe('bikes', {}, { fields: { type: 1, 'gears.rear': 1 } })

Note that from gears only one nested field will be fetched.

When you click on one list item, a new subscription is started without field projection to get the whole document:

Meteor.subscribe('bikes', _id)

All top-level and nested fields are be fetched from the database.

All top-level fields are fetched, including color which was not fetched for the list.
The nested fields are subset to the ones specified in the subscription for the list: gears.front is not fetched.