Since Rubocop warns me about missing pragma comment for freezing strings and I’m too lazy to write that every time I open a Ruby file, I’ve decided to write a template.
" Automatically add frozen string literal to the header of Ruby files.
function! RubyTemplate()
" Add pragma comment
call setline(1, '# frozen_string_literal: true')
" Add two empty lines
call append(1, repeat([''], 2))
" Place cursor on line number 3
call cursor(3, 0)
" Write file to refresh the buffer
execute "w"
endfunction
autocmd BufNewFile *.rb :call RubyTemplate()
The only downside of this approach is writing the file to disk automatically, in order to refresh the buffer.
If you know a better way to achieve this, please let me know on Twitter.