[[relate]] not working in monstache

[MihirSavjani]

Hii, I'm trying to implement the [[relate]] feature in my project, but I'm not getting the expected output.

Here's the setup:

Database: test with two collections:

1. users

   {
    "_id": "12345",
    "name": "demo"
   }

2. orders

   {
    "_id": "456",
    "userId": "12345",
    "productName": "laptop"
   }

I want to include the name from the users collection in the orders records, based on the userId. Here's the configuration in my Monstache config file:

mongo-url = "mongodb://127.0.0.1:27018/test"
elasticsearch-urls = ["http://localhost:9300"]
change-stream-namespaces = ["test.users","test.orders"]
direct-read-namespaces = ["test.users","test.orders"]
enable-http-server = true
verbose = true

[[relate]]
namespace = "test.orders"
with-namespace = "test.users"
src-field = "userId"
match-field = "_id"
keep-src = true
dot-notation = true

I'm using Monstache version 6.7.17 and Elasticsearch version 7.10.0.

After syncing, this is the data I receive in Elasticsearch:

{
  "productName": "laptop",
  "userId": "12345"
}

It seems like the userName is not being added. Could you please help me figure out what might be going wrong?

Thank you in advance!