Hi,
Shashank Mitra, that would be a topic for a very nice wiki article! 
In the meantime, I’m using a CI tool from Ferrologic which integrates with Jenkins and does unit testing and code validation (and mock services).
I also know WRIGHTIA is working on a development tool.
SonarCube code analysis examples are available on github but they seem rather cumbersome to setup.
As for unit testing, when not using Ferrologic’s solution, I setup a simple simple which calls the service to test and I them compare with the intended output.
To compare two documents a use a simple trick: I convert both documents to xml strings with pub.document:documentToXMLValues. 
Best regards,
#webMethods#Integration-Server-and-ESB#webMethods-General