For single-language projects there's no mandatory tool to use, just use the same tool across the team. For multi-language projects (e.g. Rails + React app), asdf needs to be used.
The language manager config file needs to be kept under version control.
We use Editorconfig to keep the same coding standard across our editors. Download our .editorconfig inside your project and ensure your editor is properly configured.
For Javascript we use ESLint. See our configuration. For Typescript projects we use ESLint and Prettier. See our configuration. For Ruby we use RuboCop. See our configuration;