Ah, my allow_failures system doesn't work anymore! Fixed

PHPUnit is not executed on 5.6 because only the version 5 is available

Is there a particular reason this is an issue? The tests are from 2015.

Yes, createMock and (I think) expectException don't exist. Another solution is to use PHPUnit 5 instead of the 8 for PHP 7.3

Another solution is to use PHPUnit 5 instead of the 8 for PHP 7.3

Something along those lines makes more sense to me, because PHP 7.2+ is probably what we run while writing code.

By along those lines I mean that for example PHPUnit 6/PHP 7.0 could be an interesting compromise for using features like createMock. (I can't seem to find when these methods were added.)

By along those lines I mean that for example PHPUnit 6/PHP 7.0 could be an interesting compromise for using features like createMock.

createMock is not blocking, we still can switch back to getMock. What bother me is that PHPUnit 5 and 6 are no longer supported. In the mean time, it's only used for tests, it's not like it introduces security issues in FRSS (at least, I don't think so…)

Question is: for which versions do we want to run the test suite? I implicitly answered by "PHP 7.3" because it was an easy solution: the syntax is checked for PHP 5.6 and 7.3, and the FRSS logic doesn't differ between PHP versions. Problems can happen if default values change in PHP functions from a version to another though, or using a non-existing functions. My preference was to use an up-to-date version of PHPUnit, considering that our test coverage is so low that it wouldn't make a big difference to test on several PHP versions. It's a short term opinion but we'll probably stop support of PHP 5.6 and 7.0 in few months/years (official support stopped 1 year ago).
→ Yet, I'm all opened to change to use PHPUnit 5 or 6 or 7, it's really not a big deal and it has its advantages too :)

It doesn't matter too much for now, but in principle I think the tests should be run on multiple PHP versions. It's about behavior, not about syntax.

I've setup tests for 7.1 and 7.3. I think it's more important to test latest supported versions than oldest. Also it allows to use PHPUnit 7 which is still supported for few weeks.