Load user-specific settings from XDG_CONFIG_HOME

[FranklinYu]

Is your feature request related to a problem? Please describe.

I don’t like to clutter my home directory, and I only synchronize my XDG_CONFIG_HOME.

Describe the solution you'd like

If the file ~/.rubocop.yml is missing, check whether environment variable $XDG_CONFIG_HOME is defined. If yes, then load from $XDG_CONFIG_HOME/rubocop/config.yml; otherwise load from ~/.config/rubocop/config.yml.

Describe alternatives you've considered

N/A

Additional context

Latest standard specification: https://specifications.freedesktop.org/basedir-spec/basedir-spec-0.8.html
Arch Linux Wiki: https://wiki.archlinux.org/index.php/XDG_Base_Directory

I can try PR if anyone is interested.

[bbatsov]

PRs welcome!

[FranklinYu]

I'm not familiar with the code base, but a simple search indicates that I should do it here:

https://github.com/rubocop-hq/rubocop/blob/19845704d148918eb9d7e8d00e1892fc7111854d/lib/rubocop/file_finder.rb#L43-L44

This is method is called from

https://github.com/rubocop-hq/rubocop/blob/19845704d148918eb9d7e8d00e1892fc7111854d/lib/rubocop/config_loader.rb#L77-L79

I'm still wondering whether FileFinder is used anywhere besides configuration loading? If so, modifying this file may affect other functions.

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contribution and understanding!

[FranklinYu]

This is closed by #6895 IIUC. Thanks!