For majority of packages that wraps javascript assets, the actual assets
are shipped in a libjs-* package and ruby-* package only include a
symbolic link.

At present, this means, the test will always fail in such cases since
dh_link step is not yet run when this test is run.

Details here https://lists.debian.org/debian-ruby/2024/02/msg00006.html

So I think we have a few options,

1. Run this only as an autopkgtest (like how it is currently done) which
will have the links
2. Run this tests after dh_link is done
3. Manually run dh_link before this test

To reproduce this bug, you can build this branch
https://salsa.debian.org/ruby-team/ruby-jquery-rails/-/tree/debian-tests-assets?ref_type=heads

Control: severity -1 serious

Testing further with ruby-rails-assets-underscore, the test is passing
even with a broken symbolic link.

Try building master branch which has this commit
https://salsa.debian.org/ruby-team/ruby-rails-assets-underscore/-/commit/194c526208b3be29870f745d9ac0bfbc9af6d66c

Without libjs-underscore in build depends, the test should fail, but it
is passing.

Control: severity -1 important

ruby-rails-assets-underscore source package includes underscore.js and
it is replaced by symlink to libjs-underscore only in dh_install stage
so rake assets:precompile can still find it.

So it looks like gem2deb test is working as expected, but we still need
to figure out a way out for symlinks. May be we should just link them in
the build target itself as a solution. If that is the recommended
solution, we can close this bug with a note in dh_ruby documentation.