eslint-mocha-no-only is an ESLint plugin that warns or errors when the `only()` method is used on Mocha test keywords like `describe`, `it`, `context`, etc. It's designed to prevent developers from accidentally committing `only()` calls, which would cause CI tools to run only a single test instead of the full suite. This plugin is for Mocha users who want to ensure their entire test suite runs in CI by catching forgotten `only()` calls during development.