anchor.diff:        (setf (nvim:buffer-option b "shiftwidth") 4)
         (is (equal 4 (nvim:buffer-option b "shiftwidth")))
         (setf (nvim:buffer-option b "define") "test")
  -      (is (equal "test" (nvim:buffer-option b "define")))   
  +      (is (equal "test" (nvim:buffer-option b "define")))
         (is (equal "^\\s*#\\s*define" (nvim:option "define"))))))
   
   (test number
  
positive.code:       (nvim:command "silent w!")
        (is-true (probe-file new-name)))))
  
  (test valid
    (with-fixture cleanup ()
      (nvim:command "new")
  
negative.code:       (is-true (nvim:buffer-valid-p b))
        (nvim:command "bw!")
        (is-false (nvim:buffer-valid-p b)))))
  
  (test buffers
    (with-fixture cleanup ()
      (let* ((b (nvim:current-buffer))
             (n (nvim:buffer-number b)))
        (is (= 1 (length (nvim:buffers))))
        (dotimes (i 5)
          (nvim:command "new"))
        (is (= 6 (length (nvim:buffers))))
        (is-true (find n (nvim:buffers) :key #'nvim:buffer-number))
        (setf (nvim:current-buffer) b)
        (is (= n (nvim:buffer-number (nvim:current-buffer))))
        (nvim:command "bw!")
        (is (= 5 (length (nvim:buffers))))
        (is-false (find n (nvim:buffers) :key #'nvim:buffer-number)))))
  
  (test line
    (with-fixture cleanup ()
      (let ((b (nvim:current-buffer)))
        (is (equal '("") (nvim:buffer-lines b 0 -1 T)))
        (setf (nvim:buffer-lines b 0 -1 T) '("abc" "def" "ghi"))
        (setf (nvim:buffer-line b 1) "DEF")
        (is (string= "abc" (nvim:buffer-line b 0)))
        (is (string= "DEF" (nvim:buffer-line b 1)))
        (is (string= "ghi" (nvim:buffer-line b 2)))
        (signals error (nvim:buffer-line b 5))
        (nvim:buffer-del-line b 0)
        (is (equal '("DEF" "ghi") (nvim:buffer-lines b 0 -1 T)))
        (nvim:buffer-del-line b 1)
        (is (equal '("DEF") (nvim:buffer-lines b 0 -1 T)))
        (is (string= "DEF" (nvim:buffer-line b 0)))
        (nvim:buffer-del-line b 0)
        (nvim:buffer-del-line b 0)
        (is (equal '("") (nvim:buffer-lines b 0 -1 T))))))
  
  (test lines
    (with-fixture cleanup ()
  