In addition to adding scenarios for 5.2 and 6.0, I had to do some
cleanup to get everything working well:
* Replace string-based version checks with numeric ones, and update all
version checks to treat 6+ the same as 5 (except where necessary).
* Avoid touching `ActiveSupport::Deprecation::DeprecationProxy`
instances to fix a couple of warnings in Rails 6.
* Update Bundler as part of container setup, because Rails 6's config
seems to rely on a newer version of Bundler than the one that comes
with the Ruby image.
* Update the regexes in the `show-routes` spec to be compatible with 5.2
and up.
* Add a new code path to `show-routes` for Rails 6.
* Upgrade all bundles, just for hygiene.
The Appraisal build was becoming really annoying to maintain, since
there's no one version of Ruby that can run the specs across all
supported versions of Rails. Roadshow is a tool that's similar to
Appraisal but uses Docker to test each version in an isolated
environment with the appropriate version of Ruby, at the cost of having
to maintain the Gemfiles manually.
Ryan Fitzgerald