diff --git a/src/testdir/view_util.vim b/src/testdir/view_util.vim
new file mode 100644
index 0000000..eb92630
--- /dev/null
+++ b/src/testdir/view_util.vim
@@ -0,0 +1,30 @@
+" Functions about view shared by several tests
+
+" ScreenLines(lnum, width) or
+" ScreenLines([start, end], width)
+function! ScreenLines(lnum, width) abort
+  redraw!
+  if type(a:lnum) == v:t_list
+    let start = a:lnum[0]
+    let end = a:lnum[1]
+  else
+    let start = a:lnum
+    let end = a:lnum
+  endif
+  let lines = []
+  for l in range(start, end)
+    let lines += [join(map(range(1, a:width), 'nr2char(screenchar(l, v:val))'), '')]
+  endfor
+  return lines
+endfunction
+
+function! NewWindow(height, width) abort
+  exe a:height . 'new'
+  exe a:width . 'vsp'
+  redraw!
+endfunction
+
+function! CloseWindow() abort
+  bw!
+  redraw!
+endfunction