Before:
  call ale#test#SetDirectory('/testplugin/test')

After:
  call ale#test#RestoreDirectory()

Execute(We should be able to find a configuration file further up):
  call ale#test#SetFilename('test-files/top/middle/bottom/dummy.txt')

  AssertEqual
  \ ale#path#Simplify(expand('%:p:h:h:h:h:h') . '/test-files/top/example.ini'),
  \ ale#path#FindNearestFile(bufnr('%'), 'example.ini')

Execute(We shouldn't find anything for files which don't match):
  AssertEqual '', ale#path#FindNearestFile(bufnr('%'), 'cantfindthis')