Here’s a list of all the features that you can expect from JUnit Pioneer. For some of them you need to be quite familiar with JUnit 5, so make sure to read its user guide or this article series.

@DefaultLocale and @DefaultTimeZone
JUnit Jupiter extensions to change the values returned from Locale.getDefault() and TimeZone.getDefault()
Range Sources
JUnit Jupiter argument sources for a series of numbers
@RepeatFailedTest
Repeats a failing test a certain number of times; only marking it failed if none of them pass
@ClearSystemProperty and @SetSystemProperty
JUnit Jupiter extensions to clear and set the values of system properties
TempDirectory
JUnit Jupiter extension to create and clean up a temporary directory.
Vintage @Test
A drop-in replacement for JUnit 4's @Test annotation, including expected and timeout

To start using JUnit Pioneer, determine the latest version (e.g. on Maven Central) and add org.junit-pioneer : junit-pioneer as a test dependency.