feat(routing): manual mediator pickup lifecycle management

[genaris]

Small update on Mediation Recipient module to allow stopping message pickup loop, and then restarting it anytime by calling initiateMessagePickup() manually.

An optional parameter has been added to initiateMessagePickup method in order to let start the agent with a None messagePickupStrategy (so it will not attempt to connect to mediator at the beginning) and be able to start the pickup afterwards (using any strategy we want).

So it can be used in the following way:

1. Start agent normally (with whatever Mediation Strategy you already have). It will initiate Pickup loop (V1, V2 or Implicit)
2. Call stopMessagePickup() to pause this process (e.g. when agent is offline)
3. Call initiateMessagePickup() to restart the process (e.g. agent goes online)

In case that default pickup strategy is set to None, of course, initiateMessagePickup should be called after 1 using parameters defaultMediator and the desired strategy (and the same in 3)

And I'm not completely sure, but it might also help with some failures in test suites when shutting down agents.

Resolves #753

[codecov-commenter]

Codecov Report

Merging #989 (d8f7f63) into main (c99f3c9) will decrease coverage by 0.06%.
The diff coverage is 46.66%.

@@            Coverage Diff             @@
##             main     #989      +/-   ##
==========================================
- Coverage   88.13%   88.06%   -0.07%     
==========================================
  Files         492      492              
  Lines       11613    11623      +10     
  Branches     1933     1936       +3     
==========================================
+ Hits        10235    10236       +1     
- Misses       1317     1326       +9     
  Partials       61       61              

Impacted Files	Coverage Δ
...ckages/core/src/modules/routing/RecipientModule.ts	62.01% <46.66%> (+0.40%)	⬆️
packages/core/src/logger/ConsoleLogger.ts	55.55% <0.00%> (-22.23%)	⬇️

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[TimoGlastra]

This is a great improvement. One thing I'd like to see but is probably much more work is that you can stopMessagePickup for a specific mediator. that is probably something we can add later on.

another thing we should do as a change to 0.3.0 (feel free to open a pr 😄) is to make the public api take mediator id's instead of the records.

[TimoGlastra]

can we give this a more specific name? I'm already not a huge fan I named it stop$ for the generic agent shutdown subject

[genaris]

I've set it to stopMessagePickup$ to be more specific. Didn't want it to collide with stopMessagePickup() method but, as it is a private field, it should not be confusing I think.

[TimoGlastra]

Also ran into issues with this 😆

[TimoGlastra]

I don't think there are any promises involved here?

[genaris]

True. Was part of an experiment and left it by mistake 🙈

[TimoGlastra]

much better API

[genaris]

This is a great improvement. One thing I'd like to see but is probably much more work is that you can stopMessagePickup for a specific mediator. that is probably something we can add later on.

another thing we should do as a change to 0.3.0 (feel free to open a pr 😄) is to make the public api take mediator id's instead of the records.

Thanks! I've been thinking about the management of individual message pickup loops but, as you said, requires some complexity and I think it will be better to develop it in a refactored MediationRecipient / MessagePickup module for 0.3.0.

I'll start working on these refactoring ideas (including the usage of mediatorId / connectionId) so we can discuss about it shortly.

[TimoGlastra]

Awesome, merged! Thanks for all the contributions lately :)