Fix AC::TemplateAssertions instance variables not resetting.

[tgxworld]

Fixes #16119.

[senny]

This is probably related to:

https://github.com/rails/rails/blob/master/actionpack/lib/action_controller/test_case.rb#L16-L19

and

https://github.com/rails/rails/blob/master/actionpack/lib/action_controller/test_case.rb#L59-L61

If so, we should find a common place that can be used from the different call sites.

[tgxworld]

Hmm that is strange, I actually move the reset method into AC::TemplateAssertions and thought I pushed the new commit up. Should I merge this pull request with #16027?

[tgxworld]

@senny ping in case you missed the above 😄

[senny]

@tgxworld sorry for the delayed response. I merged this one. You can rebase the other one on top and make the necessary extraction. Goal would be to have all the = nil only in one place.

[tgxworld]

@senny No worries. I didn't tagged you when I commented so I thought I might not have notified you xD Thank you for reviewing!

[tgxworld]

@rubys Is there a way that I can see the code in the controller? Looking at the code in the link above, I can't find anything wrong with it immediately yet. Thanks!

[rubys]

@tgxworld nothing special is required in the controller. See minimal test case.