Gem::Source#<=>

# File tmp/rubies/ruby-3.0.5/lib/rubygems/source.rb, line 43
def <=>(other)
  case other
  when Gem::Source::Installed,
       Gem::Source::Local,
       Gem::Source::Lock,
       Gem::Source::SpecificFile,
       Gem::Source::Git,
       Gem::Source::Vendor then
    -1
  when Gem::Source then
    if !@uri
      return 0 unless other.uri
      return 1
    end

    return -1 if !other.uri

    # Returning 1 here ensures that when sorting a list of sources, the
    # original ordering of sources supplied by the user is preserved.
    return 1 unless @uri.to_s == other.uri.to_s

    0
  else
    nil
  end
end