For our analyzers, we actually do use existing static analysis behind the scenes in addition to our custom checkers that we write by hand. So our Ruby analyzer, which is in beta at the moment, does use Rubocop behind the scenes. We’re working towards the stable release of Ruby analyzer which uses augmentations to remove false positives and decrease the noise — since guaranteeing less than 5% false positives is one of the primary values that DeepSource adds. As the anlayzer moves towards stable, we'll add custom issues to it.

The general categorization of anti-patterns is based on the consensus of the community around the language, and also some obvious things based on objective reasons. Although we understand that everyone has their own flavor of conventions — so it is very easy to triage and ignore specific issues in DeepSource.