DOCUMENTATION: Add Dead-End Services

[LBoullosa]

There is no documentation about Dead-End Services.
I asked this on Discord channel,

which name should be the right one for a dead-end service?
Where should be located under the project? ProcessingServices, Foundations.....

Response from @hassanhabib as a brief explanation,

It depends on the type of work that dead-end service does. It can be Processing and it can be Foundation - usually dead-end services tend to do something a bit more advanced so they live in the Processing layers. But every now and then they do something very basic like Add or Subtract in a calculator - they become immediately Foundation.

[hassanhabib]

We need to solve for internal mocking. We need a mechanism that is easy to override the implementation of a deadend function and replace it with an exception.
So far we have InternalMock from here.
However the solution seems incomplete - we started seeing issues due to reflection.

cc: @cjdutoit

[LBoullosa]

I see a drawback with dead-end services since it could be used/integrated by other services, it could turn into a common/helper service. Any thoughts about this @hassanhabib?

[hassanhabib]

I see a drawback with dead-end services since it could be used/integrated by other services, it could turn into a common/helper service. Any thoughts about this @hassanhabib?

@LBoullosa If it stays within it's own domain. with one single model/contract and a very specific responsibility. I think it might not be an issue. The issue with commons and helpers is that they are chaos. No common contracts, no single responsibility. They're all over the place.