Related issues

[REQUIRED] Version info

node: 12

firebase-functions: 3.15.4

firebase-tools:

firebase-admin: 9.11.1

[REQUIRED] Test case

1. Return a DocumentReference data in JSON format from a cloud function

[REQUIRED] Steps to reproduce

1. Trigger a cloud function to return a document data that has a DocumentReference field in it

[REQUIRED] Expected behavior

1. The document data to be returned as JSON correctly

[REQUIRED] Actual behavior

1. Getting error when encoding the response in JSON format.

Unhandled error Error: Data cannot be encoded in JSON: path => firestore.doc(path)

Were you able to successfully deploy your functions?

Yes

Note: The error disappeared after downgrading firebase-functions to 3.14.1. The error also will not happen if I remove the DocumentReference field from the response data