During our last engineering roundtable, we discussed the need to build more trust and confidence about how notifications currently work via more spec coverage. Our test coverage for notifications isn't at the level we would like it be and thus feature development on notifications or notification adjacent functionality has a high probability of being more involved and with more unexpected behaviors.

Describe the solution you’d like

Update the reaction notification specs

Blocked by (#19724)

This is to be done prior to this product feature request:

• On a post reaction notification, show the most recent users who have reacted #19512

Definition of Done

• Include tests for the "aggregated reactions" notification view
• Include a test that checks that a notification is indeed sent when a user reacts (in a public way - so not on moderator reactions) to an article or comment

Additional Context

• Use the new notification factory (created in Create Notification test factory #19724) as needed
• When testing, asserting that the notification worker has been triggered may not be enough; sometimes the worker's internal logic stops the notification from being sent
• When there is more than one new reaction, it should show the avatars of the first and last reactors
• New reaction count (1, 2, more) should be properly pluralized