old_contents: #!/usr/bin/env python3
  # -*- coding: utf-8 -*-
  
  from livemark.diff import _is_same_node, _next_noempty
  
  from wdom.tests.util import TestCase
  from wdom.parser import parse_html
  
  
  class TestSameNode(TestCase):
      def test_same_node(self):
          node1_src = '<h1>A</h1>'
          node1 = parse_html(node1_src)
          node2 = parse_html(node1_src)
          self.assertTrue(_is_same_node(node1.firstChild, node2.firstChild))
  
new_contents: #!/usr/bin/env python3
  # -*- coding: utf-8 -*-
  
  from livemark.diff import _is_same_node, _next_noempty
  
  from wdom.tests.util import TestCase
  from wdom.parser import parse_html
  
  
  class TestSameNode(TestCase):
      def setUp(self):
          self.src1 = '<h1>text1</h1>'
          self.src2 = '<h1>text2</h1>'
          self.src3 = '<h2>text1</h2>'
          self.text1 = 'text1'
          self.text2 = 'text2'
          self.node1 = parse_html(self.src1).firstChild
          self.node2 = parse_html(self.src2).firstChild
          self.node3 = parse_html(self.src3).firstChild
          self.t_node1 = parse_html(self.text1).firstChild
          self.t_node2 = parse_html(self.text2).firstChild
  
      def test_same_node(self):
          node1 = parse_html(self.src1).firstChild
          node2 = parse_html(self.src1).firstChild
          self.assertTrue(_is_same_node(node1, node2))
  
      def test_different_text(self):
          self.assertFalse(_is_same_node(self.node1, self.node2))
  
      def test_different_tag(self):
          self.assertFalse(_is_same_node(self.node1, self.node3))
  
      def test_same_text(self):
          node1 = parse_html(self.text1).firstChild
          node2 = parse_html(self.text1).firstChild
          self.assertTrue(_is_same_node(node1, node2))
  
      def test_different_text_node(self):
          self.assertFalse(_is_same_node(self.t_node1, self.t_node2))
  
      def test_different_tag_text(self):
          self.assertFalse(_is_same_node(self.node1, self.t_node1))
          self.assertFalse(_is_same_node(self.node2, self.t_node2))
          self.assertFalse(_is_same_node(self.node3, self.t_node1))
  
subject: Add test for same node check