Clarify JUnit XML format

Problem to Solve

I would like to request a clarification in the documentation about the supported JUnit XML standard.

The docs states that GitLab support test reports in the JUnit report format. However, JUnit does not seem to have a commonly agreed standard. For example it's stated that "There are several self-proclaimed JUnit formats. Apache Ant doesn't have skipped elements at all and junit5's skipped elements can't have any attributes."

By experimentation with GitLabs Test pane, I found that the Suite column is populated by testcase classname and Name column is populated by testcase name. Meaning this:

<testsuites>
   <testsuite name="mySuite" tests="1" failures="1" errors="0" skipped="0">
      <testcase classname="myClass" name="myName"/>
         <failure type="failure">myFailure</failure>
      </testcase>
   </testsuite>
</testsuites>

will output Suite: myClass (not mySuite) and Name: myName in Gitlab. The mySuite value does not seem to appear anywhere.

The GitLab docs refer to IBM's standard - JUnit report format XML files - but this does not mention any classname attribute. On the other hand, classname is specified in both junit5 and Apache Ant JUnit (not sure if this one's official).

Proposal

1. Better document the supported JUNIT elements in docs
2. Create a blog post / example project that shows what is and what might not be supported
3. Iterate on how we parse/display unknown fields to better support working by default (here's a raw dump of your extra data?)