text: """Test the only directive with the test root."""
  
  import re
  
  import pytest
  from docutils import nodes
  
  
  @pytest.mark.sphinx('text', testroot='directive-only')
  def test_sectioning(app, status, warning):
  
      def getsects(section):
          if not isinstance(section, nodes.section):
              return [getsects(n) for n in section.children]
          title = section.next_node(nodes.title).astext().strip()
          subsects = []
          children = section.children[:]
          while children:
              node = children.pop(0)
              if isinstance(node, nodes.section):
                  subsects.append(node)
                  continue
              children = list(node.children) + children
          return [title, [getsects(subsect) for subsect in subsects]]
  
      def testsects(prefix, sects, indent=0):
          title = sects[0]
          parent_num = title.split()[0]
          assert prefix == parent_num, \
              'Section out of place: %r' % title
          for i, subsect in enumerate(sects[1]):
              num = subsect[0].split()[0]
              assert re.match('[0-9]+[.0-9]*[.]', num), \
                  'Unnumbered section: %r' % subsect[0]
              testsects(prefix + str(i + 1) + '.', subsect, indent + 4)
  
      app.builder.build(['only'])
      doctree = app.env.get_doctree('only')
      app.env.apply_post_transforms(doctree, 'only')
  
      parts = [getsects(n)
               for n in [_n for _n in doctree.children if isinstance(_n, nodes.section)]]
      for i, s in enumerate(parts):
          testsects(str(i + 1) + '.', s, 4)
      assert len(parts) == 4, 'Expected 4 document level headings, got:\n%s' % \
          '\n'.join([p[0] for p in parts])
  