new file mode 100644
--- /dev/null
+++ b/src/testdir/test_wnext.vim
@@ -0,0 +1,101 @@
+" Test :wnext :wNext and :wprevious
+
+func Test_wnext()
+  args X1 X2
+
+  call setline(1, '1')
+  wnext
+  call assert_equal(['1'], readfile('X1'))
+  call assert_equal('X2', bufname('%'))
+
+  call setline(1, '2')
+  call assert_fails('wnext', 'E165:')
+  call assert_equal(['2'], readfile('X2'))
+  call assert_equal('X2', bufname('%'))
+
+  " Test :wnext with a single file.
+  args X1
+  call assert_equal('X1', bufname('%'))
+  call assert_fails('wnext', 'E163:')
+
+  " Test :wnext with a count.
+  args X1 X2 X3
+  call assert_equal('X1', bufname('%'))
+  2wnext
+  call assert_equal('X3', bufname('%'))
+
+  " Test :wnext {file}.
+  args X1 X2 X3
+  wnext X4
+  call assert_equal(['1'], readfile('X4'))
+  call assert_equal('X2', bufname('%'))
+  call assert_fails('wnext X4', 'E13:')
+  call assert_equal(['1'], readfile('X4'))
+  wnext! X4
+  call assert_equal(['2'], readfile('X4'))
+  call assert_equal('X3', bufname('%'))
+
+  args X1 X2
+  " Commented out as, E13 occurs on Windows instead of E17
+  "call assert_fails('wnext .', 'E17:')
+  call assert_fails('wnext! .', 'E502:')
+
+  %bwipe!
+  call delete('X1')
+  call delete('X2')
+  call delete('X3')
+  call delete('X4')
+endfunc
+
+func Test_wprevious()
+  args X1 X2
+
+  next
+  call assert_equal('X2', bufname('%'))
+  call setline(1, '2')
+  wprevious
+  call assert_equal(['2'], readfile('X2'))
+  call assert_equal('X1', bufname('%'))
+
+  call setline(1, '1')
+  call assert_fails('wprevious', 'E164:')
+  call assert_fails('wNext', 'E164:')
+
+  " Test :wprevious with a single file.
+  args X1
+  call assert_fails('wprevious', 'E163:')
+  call assert_fails('wNext', 'E163:')
+
+  " Test :wprevious with a count.
+  args X1 X2 X3
+  2next
+  call setline(1, '3')
+  call assert_equal('X3', bufname('%'))
+  2wprevious
+  call assert_equal('X1', bufname('%'))
+  call assert_equal(['3'], readfile('X3'))
+
+  " Test :wprevious {file}
+  args X1 X2 X3
+  2next
+  call assert_equal('X3', bufname('%'))
+  wprevious X4
+  call assert_equal(['3'], readfile('X4'))
+  call assert_equal('X2', bufname('%'))
+  call assert_fails('wprevious X4', 'E13:')
+  call assert_equal(['3'], readfile('X4'))
+  wprevious! X4
+  call assert_equal(['2'], readfile('X4'))
+  call assert_equal('X1', bufname('%'))
+
+  args X1 X2
+  " Commented out as, E13 occurs on Windows instead of E17
+  "call assert_fails('wprevious .', 'E17:')
+  call assert_fails('wprevious! .', 'E502:')
+
+  %bwipe!
+  call delete('X1')
+  call delete('X2')
+  call delete('X3')
+  call delete('X4')
+endfunc