Catch up on JUnit 4 Runner support for custom ClassLoaders

[rmannibucau]

Runners in JUnit 4 were a great way to control the test environment and instance from user land (without writing an engine).

It would be great if JUnit Jupiter would allow one to do the same.

The main challenge is controlling the test instance redefining a custom @Test.

[sormuras]

Does the TestInstanceFactory extension point already help your use-case?

[sormuras]

What about the TestInstancePostProcessor extension?

[rmannibucau]

the processor is way too late (the instance exists so it does not help at all), test instance factory works (but requires the last release, i was on the 5.3.0-M1) but can likely be enhanced to be supported per test and not only globally (the API is not called when defined on a test method)

thanks for the heads up anyway, wouldnt have noticed the bad version otherwise

edit: the instance factory has the issue to require the produced instance to match the testClass - likely for the later reflection - so i can't produce it with another classloader. What i want to do is just:

1. change the TCCL
2. get a test instance using this new loader
3. ensure the @test pass (ie the method is looked up in the instance created at 2)

[sbrannen]

@rmannibucau, based on your latest feedback, I am closing this as a duplicate of #201.

Feel free to participate in the discussion in #201.

[rmannibucau]

Oki, i will just note that willing to handle all particular cases instead of providing a generic API as junit4 was is going to be a lot more complex and less powerful even if the api is a bit more fun so probably time to rationalize junit5 instead of fixing cases one by one.