commit https://github.com/vim/vim/commit/b5ae48e9ffd3b8eb6ca4057de11f1bddcde8ce6f Author: Bram Moolenaar <Bram@vim.org> Date: Fri Aug 12 22:23:25 2016 +0200 patch 7.4.2204 Problem: It is not easy to get information about buffers, windows and tabpages. Solution: Add getbufinfo(), getwininfo() and gettabinfo(). (Yegappan Lakshmanan)

" Test for joining lines.

func Test_join_with_count()
  new
  call setline(1, ['one', 'two', 'three', 'four'])
  normal J
  call assert_equal('one two', getline(1))
  %del
  call setline(1, ['one', 'two', 'three', 'four'])
  normal 10J
  call assert_equal('one two three four', getline(1))
  quit!
endfunc