Unstable delivery in when more than one consumer is used

[piotrwielgolaski-tomtom]

In my case I have 5 consumer register for queue, all works file in 90% of cases.
Occassionally it crash in MockQueue::deliverToConsumerIfPossible with NPE.
1/ NPE is not catch and whole delivery is broken
2/ map from

rabbitmq-mock/src/main/java/com/github/fridujo/rabbitmq/mock/MockQueue.java

Line 46 in e697113

private final Map<String, ConsumerAndTag> consumersByTag = new LinkedHashMap<>();

is unstable it say it has size 5, but in fact has less elements

I think (2) could be easier fixed with concurrent version of map.

[ledoyen]

Hello @piotrwielgolaski-tomtom , thank you for reporting this.

Could you provide a sample test that demonstrates the issue ? (even if it is flaky and should not fail most of the time)

Thank you !

[ledoyen]

Should be fixed with #318