RuboCop

Report style violations and likely bugs with file-level context

Running rubocop at a project root recursively inspects eligible Ruby files and reports the line, column, severity, cop name, and explanation for each offense. Its lint rules can flag suspicious code as well as style inconsistencies.

Sources: [1]

Choose configuration and correction behavior deliberately

Teams can tune rules in .rubocop.yml, apply only safe corrections with -a, or include corrections that are not guaranteed safe with -A. Version 1.91.0 also adds --changed for Git-reported changed files and --diff for previewing corrections without writing them.

The built-in LSP server provides feedback in compatible editors. Rails, RSpec, and Performance cops are separate gems, so projects install only the extensions they need.

Sources: [1][2]

Introduce a shared Ruby quality baseline incrementally

It fits teams that want the same checks in an editor, a local command, and CI. Repositories with a large existing offense count can start with changed files or generate a TODO configuration, then tighten the baseline over time.

Sources: [1][2]

Confirm Ruby compatibility, configuration changes, and autocorrect diffs

Version 1.91.0 runs on MRI 2.7 or later and JRuby 9.4 or later, while analyzing Ruby 2.0 or later. The project aims for stability across minor releases, but upgrades still require a review of configuration changes and newly introduced cops; pin the gem version appropriately.

-A includes corrections that are not guaranteed safe. Save the current work in version control and review the diff and tests after using it. The software is MIT-licensed, while the project logo is documented under a separate license.

Sources: [1][3][4]