Goal

Add support for some level of parallelization inside the Junit Vintage engine.
Ideally the level of configuration should be similar to maven surefire parallel options.

Why

When including junit 5 tests in a project containing junit4 tests the natural path is to use junit 5 platform with the jupiter and vintage engines.

However this causes problem with parallelization.
In a project with Junit4 tests only maven surefire level parallelization works fine. (See https://maven.apache.org/surefire/maven-surefire-plugin/examples/fork-options-and-parallel-execution.html).
For Junit5 tests the jupiter engine parallel execution works great.

However when a project contains a mix of Junit4 and Junit 5 there is no great way to configure parallelism:

• Surefire parallel does not work with Junit Platform Provider so it's not an option
• Surefire forkCount or gradle maxParallelForks can be used but:
  • It's not available at all when using tycho surefire
  • It introduces some memory and execution time overhead compared to surefire parallel or junit 5 parallel.
  • It provides less control than Junit 5 parallel execution options.
• Combining fork + junit 5 parallel execution leads to more parallel executions than expected when executing junit 5 tests because parallelization is done at two level.

Another option is to configure two distinct test tasks one for junit 4 using surefire parallel and one for junit 5 but it kind of defeats the point of junit platform.

Deliverables

• Not sure