@CartesianCsvSource for @CartesianProductTest

Following #409, it would be nice to have @CartesianCsvSource which mimics @CsvSource.

Example:

@CartesianProductTest
@CartesianValueSource(ints = { 1, 2 })
@CartesianCsvSource({
  "A, B",
  "C, D",
  "E, F",
})
void moreParams(int i, String s1, String s2) {
  // some test code
}

should generate 6 tests:

Test #	i	s1	s2
1	1	A	B
2	2	A	B
3	1	C	D
4	2	C	D
5	1	E	F
6	2	E	F

[Michael1993]

I’m wondering though, why there exists such a limitation? I think it would be nicer if one could use JUnit’s standard param annotations instead of the the practically similar @CartesianX ones.

@mizosoft There is a bit of a clash.

When you create a @ParameterizedTest, you supply a single (!) @ArgumentsSource annotation where you define every test case. This is also the reason why annotations annotated with @ArgumentsSource (e.g.: @CsvSource or @ValueSource) are not @Repeatable.

This is different from @CartesianProductTest, where you want to define argument sets for each parameter individually and let the extension define the test cases. This is an entirely different approach from @ParameterizedTest.

We cannot support the annotations used by @ParameterizedTest because we would need them to be @Repeatable. They (probably) never will be repeatable because their design philosophy is different from what we need.

[nipafx]

Can you two take another look at this and come to a decision whether something could be done here given the new approach to Cartesian tests and what that “something” could look like?