Before:
  call ale#assert#SetUpLinterTest('xml', 'xmllint')

After:
  call ale#assert#TearDownLinterTest()

Execute(The xml xmllint command callback should return the correct default string):
  AssertLinter 'xmllint', ale#Escape('xmllint') . ' --noout -'

Execute(The xml xmllint command callback should let you set options):
  let g:ale_xml_xmllint_options = '--xinclude --postvalid'

  AssertLinter 'xmllint',
  \ ale#Escape('xmllint') . ' --xinclude --postvalid --noout -'

Execute(The xmllint executable should be configurable):
  let g:ale_xml_xmllint_executable = '~/.local/bin/xmllint'

  AssertLinter '~/.local/bin/xmllint',
  \ ale#Escape('~/.local/bin/xmllint') . ' --noout -'