CrudBatch hasMore + onChange improvement

[stevensJourney]

Overview

CrudBatch

This fixes a bug where the hasMore value of CrudBatch was always false.

onChange

This adds a triggerImmediately parameter to the onChange API similar to the Dart API. Adding this makes it easy to avoid race conditions in consumers such as the Swift SDK.

[simolus3]

The CRUD changes look good to me.

Adding this makes it easy to avoid race conditions in consumers such as the Swift SDK.

What race conditions are we aiming to avoid with this? It's not immediately clear to me, so maybe you have an example where it helps that we have an initial emit right away?

[stevensJourney]

The CRUD changes look good to me.

Adding this makes it easy to avoid race conditions in consumers such as the Swift SDK.

What race conditions are we aiming to avoid with this? It's not immediately clear to me, so maybe you have an example where it helps that we have an initial emit right away?

In Swift we'd like to use the onChange method to implement the watch method. Doing this gives the Swift SDK the ability to control and catch any exceptions which might occur when performing the corresponding getAll query.

It can become tricky to control the emission of the first watched query result and starting a Task which listens to events from an onChange stream and then executes a getAll updating the resultant stream. It's not impossible to manage this, but having the onChange method emit an initial event makes the implementation much simpler.

[simolus3]

I see, thanks for the explanation 👍