Firestore - How to decrement integer value atomically in database?

Question

Firestore has recently launched a new feature to increment and decrement the integer values atomically.

I can increment the integer value using

For instance, FieldValue.increment(50)

But how to decrement ?

I tried using FieldValue.decrement(50) But there is no method like decrement in FieldValue.

It's not working.

https://firebase.googleblog.com/2019/03/increment-server-side-cloud-firestore.html?linkId=65365800&m=1

Answer 1

To decrement the value in a field, do a negative increment. So:

FieldValue.increment(-50)