Execute(ale#path#Dirname should return empty strings should be returned for empty values):
  AssertEqual '', ale#path#Dirname('')
  AssertEqual '', ale#path#Dirname(0)
  AssertEqual '', ale#path#Dirname(v:null)

Execute(ale#path#Dirname should return the dirname of paths):
  AssertEqual '/foo', ale#path#Dirname('/foo/bar')
  AssertEqual '/foo', ale#path#Dirname('/foo/bar/')

  if has('win32')
    AssertEqual 'C:\foo', ale#path#Dirname('C:\foo\bar')
    AssertEqual 'C:\foo', ale#path#Dirname('C:\foo\bar\')
  endif