[FSSDK-8501] fix: gracefully close client to dispatch queued events

[pulak-opti]

Ticket: FSSDK-8501

[mikechu-optimizely]

LGTM.

I posted just a few questions, mostly because I don't know Go too well.

[yasirfolio3]

Are we sure we need this change? I think this is already part of sdk implementation, this test also verifies it: https://github.com/optimizely/go-sdk/blob/master/pkg/event/processor_test.go#L348 unless we are trying something else here? eg.TerminateAndWait() makes sure all events are dispatched before close is completed.

[pulak-opti]

Are we sure we need this change? I think this is already part of sdk implementation, this test also verifies it: https://github.com/optimizely/go-sdk/blob/master/pkg/event/processor_test.go#L348 unless we are trying something else here? eg.TerminateAndWait() makes sure all events are dispatched before close is completed.

Actually, this is the go routine https://github.com/optimizely/go-sdk/blob/master/pkg/event/dispatcher.go#L99 which fails to finish dispatching all queued events for a sudden client.Close()

and this is called here https://github.com/optimizely/go-sdk/blob/master/pkg/event/processor.go#L323

[yasirfolio3]

LGTM, just some minor suggestions. Also, please update the file headers with 2023