Lately (not sure since when), from time to time we've been getting these
failures in our CI:
```
Failures:
1) CommentsHelper#comment_author_class returns is-author if author is the commenting user
Failure/Error: comment = instance_double(Comment, user_id: author_id)
the Comment class does not implement the instance method: user_id
# ./spec/helpers/comments_helper_spec.rb:48:in `block (3 levels) in <top (required)>'
# ./spec/spec_helper.rb:40:in `block (3 levels) in <top (required)>'
# ./spec/spec_helper.rb:39:in `block (2 levels) in <top (required)>'
2) CommentsHelper#comment_author_class returns an empty string if commenter is not the author
Failure/Error: comment = instance_double(Comment, user_id: author_id - 1)
the Comment class does not implement the instance method: user_id
# ./spec/helpers/comments_helper_spec.rb:55:in `block (3 levels) in <top (required)>'
# ./spec/spec_helper.rb:40:in `block (3 levels) in <top (required)>'
# ./spec/spec_helper.rb:39:in `block (2 levels) in <top (required)>'
```
It might be related to the upgrade of rspec-rails done in commit
6fe222148 or maybe due to a change in github actions that caused some
tests to fail, as described in commits bedcb5bca and 3e44eeaee.
What might be causing the issue is the usage of `instance_double`
stubbing different methods in different tests (not sure this is the
cause, though).
We've seen that somebody got a similar error [1] (although it might not
have been for the same reason) and one of the maintainers of rspec-mocks
replied:
> I would recommend switching to double (as you mentioned) or
> refactoring to use something more defined.
So we're simply using `double`, which is what we usually use when
stubbing objects in the tests. Doing so is faster than further
investigating why the `instance_double` isn't reliable 100% of the time.
[1] See issue 1587 in https://github.com/rspec/rspec-mocks/
f721e88af8