Sonar + maven principle


SonarQube requires quite some configuration to be fully useful!

This article explains the key principles + what is UNIT and INTEGRATION tests from my point of view.


Principle

What are Unit / Integration tests ?

By default "code coverage" only consider the tests from the same projects.


Let's take an example to make things easier...

Consider a project with 4 modules such as:

Project structure


Then consider the following inter-dependencies:

Project inter-dependencies


Definition:

  • Unit Tests coverage (UT)

= code coverage for each module only.

== How much tests of 'module A' test 'module A' ??


  • Integration Tests coverage (IT)

= overall code coverage.

== Once global compilation and all the tests have been run, how much of 'module A' was used and covered ?


Process overview

To work well SonarQube requires a bit of Maven configuration + Jenkins build adjustment:

  • Maven specific properties
  • Maven build plug-ins
    • Maven-jacoco (code coverage tool)
    • Maven-surefire (unit tests reports)
    • Maven-failsafe (integration tests reports)


Key points:

  • SONAR is configured for JAVA language and it will use Jacoco as coverage tool.
  • Each Maven module will have its own Unit Tests results (Surefire reports + .exec file) inside its own target directory
  • The Integration Tests results are common. Meaning:
    • all modules will write in the same directory
    • That directory is relative to the maven execution
    • All reports will be aggregated