Reactive variables only update cache when query polling is enabled

[Steven-Ireland]

Intended outcome:

Updating the value of a reactive variable should broadcast the local state change to the cache and update any dependent queries

Actual outcome:

Above behavior only occurs when {pollInterval: XXX} is passed to useQuery, and only after the first poll has been completed

How to reproduce the issue:

I have a codesandbox with the issue: https://codesandbox.io/s/apollo-reactivevars-only-work-with-polling-enabled-kk8b3. List items can be "selected" via click with the selected ids stored in a reactive variable.

In the example I've set pollInterval to 5000, the following things can be observed:

1. No local state changes apply before the 5000 ms has passed
2. After the 5000ms, any local state changes are reflected in the query immediately
3. Removing the poll interval entirely causes local state changes to never update the query

Versions

3.3.7, see codesandbox

[jcreighton]

Looks like this was also reported in #7593.

[jcreighton]

Should be fixed with #7657.