Directives body opt

[livius-ungureanu]

Problem:

The app should be signaled somehow by op-rabbit about an unparsable item delivered by RabbitMQ in order to take specific actions.(e.g. raise specific service logs, increment specific stats etc..)

Solution:

To address this case we'd need a new directive in order to signal in invalid message(i.e. unparsable message) to the client code:

 bodyEither(as[JobDescription]) { jobDescriptionEither => // alarm the reason and take specific action

[livius-ungureanu]

Note: currently this is on top of add more tls support PR

[livius-ungureanu]

I'd like to also add in DirectivesSpec a test to prove that when the unmarashalling of the body fails then a Either.Left is produced with the cause.
Unfortunately, the only unmarshallers visisble in DirectivesSpec are UTF8StringMarshaller and BinaryMarshaller so it hard to make marshaling fail.

In order to achieve this the import com.spingo.op_rabbit.PlayJsonSupport._ needs to be resolved in DirectivesSpec which currently does not happen due to project structure. If there is a workarround to this I'd be happy to also add Either.Left test. Though I tested successfully the Either.Left in a mini app where I could import anything I needed.

[timcharper]

Op-rabbit already supports the | operator. One could do

(body(as[JobDescription]).map(Right(_))) | (body(as[String]).map(Left(_)))

Also, op-rabbit has support for publishing failed items to an error queue, I believe, isn't this one of the strategies? Maybe this would be a way to handle failed parsing?

[livius-ungureanu]

 bodyEither(as[JobDescription]) { jobDescriptionEither => // alarm the reason and take specific action

would make the library user a bit happier because:

1. the low level (parsing) exception is captured in the jobDescriptionEither so it can be logged
2. more ergonomic and user friendly.

[scirstoiu]

I am also interested in this feature