I am using Server Sent Events for my small chat application, and I am storing a list of sent events on my server, along with passing an id field with SSE message.

Server Sent Events apparently has a concept of automatic reconnection, but I cannot seem to find a single instance where this actually occurs in practice.

For example, if you are on Android and tab out of the application, wait 30 seconds, and then tab back in, then the connection is broken. But the onerror event never occurs, and the readyState stays OPEN. So the only option to handle this situation seems to poll for heartbeats and do a manual reconnection by re-initializing the EventSource object if curr_time - last_heartbeat > heartbeat_interval

Another instance of disconnection is when you for example disable WiFI and then re-enable it. However, when this occurs, Android Chrome just automatically refreshes the page, so reconnection doesn't occur here either (instead it's just refresh which causes a disconnect and then a fresh connection).

So, am I missing something? SSE is touted as being very robust for its automatic reconnection ability, but I cannot find a single case where it actually performs a reconnection. What instances are there where a reconnection can actually occur, such that I can test this behavior?