[TASK] Use DeclarationList in the tests

[JakeQZ]

The interface was renamed from RuleContainer in #1530.

Also accordingly rename the trait that provides test methods for implementing classes.

[JakeQZ]

For some reason the CI build can't find the renamed class, but it works fine on my machine.

[oliverklee]

The casing of the directory is incorrect (unit instead of Unit). I guess that's hard to fix on Windows. I'll take care of it.

[oliverklee]

While we're renaming the trait anyway, I'd prefer we don't use the Test prefix for it. This prefix should only be used for testcase classes, not for traits. (Also, this will allow us to have a DeclarationListTest in the future if we want it.)

[coveralls]

coverage: 72.384%. remained the same
when pulling 1b9c53d on task/tests/declarationlist
into eaa13f3 on main.

[oliverklee]

For some reason the CI build can't find the renamed class, but it works fine on my machine.

… which is a Windows machine that uses a case-insensitive file system. 😄

[JakeQZ]

The casing of the directory is incorrect (unit instead of Unit). I guess that's hard to fix on Windows. I'll take care of it.

Ah. Directory names aren't case sensitive in Windows. I guess lowercase unit somehow ended up in the git mv part of the commit.

While we're renaming the trait anyway, I'd prefer we don't use the Test prefix for it. This prefix should only be used for testcase classes, not for traits. (Also, this will allow us to have a DeclarationListTest in the future if we want it.)

I think you mean suffix. I'm open to alternative suggestions - DeclarationListTester?

[oliverklee]

I think you mean suffix. I'm open to alternative suggestions - DeclarationListTester?

Ah, yes, of course suffix.

I‘d be equally fine with DeclarationListTester as well as SharedDeclarationListTests.

[JakeQZ]

I‘d be equally fine with DeclarationListTester as well as SharedDeclarationListTests.

Maybe DeclarationListTests - it says what it provides via use (it's not a tester itself, and that it might be shared between TestCases is perpahps not relevant to the trait itself)...

[oliverklee]

Then let‘s go with DeclarationListTests.