Rails::BacktraceCleaner compatibility.

[lime-boorse]

The implementation of Rails::BacktraceCleaner filters out everything that doesn't come from the app, config, lib, or test directories, which obviously impacts using packs to organize a Rails codebase. I also noticed this was raised in the Rails forum here.

Would it make sense to have an implementation of this in packs-rails, which inherits from ActiveSupport::BacktraceCleaner, and it adds the packs directory?

Something like:

APP_DIRS_PATTERN = /\A(?:\.\/)?(?:app|config|lib|test|packs|\(\w*\))/
# ...
add_silencer { |line| !APP_DIRS_PATTERN.match?(line) }

The alternative to this is to call remove_filters! on the Rails::BacktraceCleaner, but obviously this would remove a bunch of useful configuration that we're getting from the ActiveSupport::BacktraceCleaner.

[iangorham]

As a stop-gap, I put this in config/initializers/backtrace_silencers.rb:

class Rails::BacktraceCleaner < ActiveSupport::BacktraceCleaner
  # Remove the existing constant first to avoid a const redefinition warning
  remove_const :APP_DIRS_PATTERN if const_defined?(:APP_DIRS_PATTERN)
  APP_DIRS_PATTERN = %r{\A(?:\./)?(?:app|config|lib|test|packs|\(\w*\))}
end

Not ideal, but it was absolutely going to drive me nuts if I didn't fix it.

[ivy]

Hey folks! This is Ivy from the Modularity team. 👋 Thanks for being patient, this is a difficult issue that we currently solve internally with a pretty custom solution. @iangorham's suggestion is a good stopgap and very similar to what we do currently.

The gist of our thoughts on this is that it would be a very complex change beyond the scope of packs-rails to offer any custom of BacktraceCleaner. @martinemde (also from the Modularity team) has suggested that a change should be upstreamed to Rails::BacktraceCleaner to allow it to support customizations without monkey patching.