Allow developer control of parallel testing

[MarkEWaite]

Allow developer control of parallel testing

Move the definition of parallel testing from the Maven pom file into the Jenkinsfile so that ci.jenkins.io continues to run the tests with one process per available core, while developers are allowed to configure the amount of parallel testing based on the configuration and use of their computer.

Developers can adjust parallel execution by passing a command line argument to Maven like this:

  mvn clean -DforkCount=1C verify

Developers can define a Maven profile that sets the forkCount in their
~/.m2/settings.xml like this:

  <profile>
    <id>faster</id>
    <activation>
      <activeByDefault>true</activeByDefault>
    </activation>
    <properties>
      <forkCount>.45C</forkCount>
    </properties>
  </profile>

With that entry in the settings.xml file, then 0.45C will be used for:

  mvn clean verify

Testing done

Tests pass with -DforkCount=1C on my Linux computer with Java 11.

Submitter checklist

• Make sure you are opening from a topic/feature/bugfix branch (right side) and not your main branch!
• Ensure that the pull request title represents the desired changelog entry
• Please describe what you did
• Link to relevant issues in GitHub or Jira
• Link to relevant pull requests, esp. upstream and downstream changes
• Ensure you have provided tests - that demonstrates feature works or fixes the issue

[codecov]

Codecov Report

Merging #942 (9f58cce) into master (8c39121) will not change coverage.
The diff coverage is n/a.

@@            Coverage Diff            @@
##             master     #942   +/-   ##
=========================================
  Coverage     92.92%   92.92%           
  Complexity     2338     2338           
=========================================
  Files           345      345           
  Lines          6499     6499           
  Branches        672      672           
=========================================
  Hits           6039     6039           
  Misses          262      262           
  Partials        198      198           

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[uhafner]

I think it would make more sense to simply revert:

848f6ce

[MarkEWaite]

I think it would make more sense to simply revert:

848f6ce

If that works better for you, that's fine as well. I thought that the reduction in test time and the resulting savings in cloud costs was generally worth it, but in this repository it is only a 5% savings, so parallel tests may not add enough value here.