TestSubscriptionsBasic flaky

[kjk]

https://ci.appveyor.com/project/ravendb/ravendb-go-client/builds/23144627/job/ge467894jiqskbqv?fullLog=true#L4358

Could be just networking issue with the machine.

--- FAIL: TestSubscriptionsBasic (5.84s)
    subscriptions_basic_test.go:286: 
        	Error Trace:	subscriptions_basic_test.go:286
        	            				asm_amd64.s:1333
        	Error:      	Not equal: 
        	            	expected: "Adam"
        	            	actual  : "James"
        	            	
        	            	Diff:
        	            	--- Expected
        	            	+++ Actual
        	            	@@ -1 +1 @@
        	            	-Adam
        	            	+James
        	Test:       	TestSubscriptionsBasic
    subscriptions_basic_test.go:286: 
        	Error Trace:	subscriptions_basic_test.go:286
        	            				asm_amd64.s:1333
        	Error:      	Not equal: 
        	            	expected: "David"
        	            	actual  : "Adam"
        	            	
        	            	Diff:
        	            	--- Expected
        	            	+++ Actual
        	            	@@ -1 +1 @@
        	            	-David
        	            	+Adam
        	Test:       	TestSubscriptionsBasic
=== RUN   TestSuggestionsLazy

[ayende]

Try logging all the previous values that you go there. It might have called this twice?
Or there was an error and it retired?

[kjk]

It looks like (sometimes) we don't get the first expected value, created before subscription.Run.

[ayende]

In here:
https://github.com/ravendb/ravendb-go-client/blob/master/tests/subscriptions_basic_test.go#L271

And:
https://github.com/ravendb/ravendb-go-client/blob/master/subscription_worker.go#L427

You are putting the batch into a channel, but it looks like this instance is being reused, so you are getting data races.
If this is a common setup in Go, this is probably a real pitfall and we need to make sure that we won't be re-using this instance.

[kjk]

For that reason the callback receives a copy of SubscriptionBatch: https://github.com/ravendb/ravendb-go-client/blob/master/subscription_worker.go#L444

[ayende]

But you are passing the Item instance, isn't that mutable?

[kjk]

.Items gets re-created from scratch in each iteration in https://sourcegraph.com/github.com/ravendb/ravendb-go-client@master/-/blob/subscription_batch.go#L87 called from https://sourcegraph.com/github.com/ravendb/ravendb-go-client@2c2cde5258d42e531d03f95fa98713cb6e1b8135/-/blob/subscription_worker.go#L437

[ayende]

Okay, make sense.

When you check the logs, see if you can also log what comes from the network. I think this is a Go client problem, not a server one