text: from pathlib import Path
  
  import pytest
  
  
  @pytest.mark.parametrize("test_app", [{"buildername": "html", "srcdir": "doc_test/doc_needextend"}], indirect=True)
  def test_doc_needextend_html(test_app):
      app = test_app
      app.build()
      index_html = Path(app.outdir, "index.html").read_text()
      assert "extend_test_003" in index_html
  
      assert (
          '<div class="line">links outgoing: <span class="links"><span><a class="reference internal" href="#extend_'
          'test_004" title="extend_test_003">extend_test_004</a></span></span></div>' in index_html
      )
  
      assert (
          '<div class="line">links outgoing: <span class="links"><span><a class="reference internal" href="#extend_'
          'test_003" title="extend_test_006">extend_test_003</a>, <a class="reference internal" href="#extend_'
          'test_004" title="extend_test_006">extend_test_004</a></span></span></div>' in index_html
      )
  
      page_1__html = Path(app.outdir, "page_1.html").read_text()
      assert (
          '<span class="needs_data_container"><span class="needs_data">tag_1</span><span class="needs_spacer">, '
          '</span><span class="needs_data">new_tag</span><span class="needs_spacer">, '
          '</span><span class="needs_data">another_tag</span></span>' in page_1__html
      )
  