exhale

https://github.com/tools4imps/exhale-ruby

exhale is the contraction toolkit for the exhale of every pull request in a Rails app. Its first check, exhale dry, sweeps the whole codebase for duplicated Ruby and ERB, scores near-copies by rarity-weighted structural similarity, and fails the build while any copy is undeclared. Deliberate duplication is declared in the Contract, next to the reason for it. Built on Prism and Herb.