These tests can flake when we get a notification for an earlier event.
Retry the read from update channel a few times to make sure we get the
event we expect.
Split the TestStreamingClient into the two logical components the real
client uses. This allows us to test multiple clients properly.
Previously writing of ctx from multiple Subscribe calls was showing a
data race.
Once this was fixed a test started to fail because the request had to be
made with a greater index, so that the store.Get call did not return
immediately.
The idleTTL was being written and read concurrently. Instead move the idleTTL to a struct
field so that when one test patches the TTL it does not impact others.
The background goroutines for the store can outlive a test because context cancellation
is async.
Remove View.Result error return value, it was always nil, and seems like it will likely always remain nill
since it is simply reading a stored value.
Also replace some cache types with local types.
And only start expiration time when the last request ends. This makes tracking expiry simpler, and
ensures that no entry can be expired while there are active requests.
Daniel Nephin