old_contents: import pytest
  
  import compas
  
  from compas.datastructures import Mesh
  from compas.datastructures import mesh_insert_vertex_on_edge
  from compas.datastructures import mesh_substitute_vertex_in_faces
  
  
  @pytest.fixture
  def mesh_0():
      vertices = [
          [1.0, 0.0, 0.0], 
          [1.0, 2.0, 0.0],
          [0.0, 1.0, 0.0],
          [2.0, 1.0, 0.0],
          [0.0, 0.0, 0.0],
      ]
      faces = [
          [0, 1, 2],
          [0, 3, 2]
      ]
      
      return Mesh.from_vertices_and_faces(vertices, faces)
  
  
  def test__insert_vertex_on_edge(mesh_0):
      mesh_insert_vertex_on_edge(mesh_0, 0, 1)
      assert mesh_0.face_degree(0) == 4
      assert mesh_0.face_degree(0) == 4
      assert mesh_0.face_vertex_descendant(0, 0) == 5
      assert mesh_0.face_vertex_descendant(1, 1) == 5
  
      mesh_insert_vertex_on_edge(mesh_0, 0, 2, 4)
      assert mesh_0.face_degree(0) == 5
      assert mesh_0.face_vertex_descendant(0, 2) == 4
  
  
  def test_mesh_substitute_vertex_in_faces(mesh_0):
      mesh_substitute_vertex_in_faces(mesh_0, 0, 4)
      assert 4 in mesh_0.face_vertices(0)
      assert 0 not in mesh_0.face_vertices(0)
      assert 4 in mesh_0.face_vertices(1)
      assert 0 not in mesh_0.face_vertices(1)
      mesh_substitute_vertex_in_faces(mesh_0, 4, 0, 1)
      assert 4 in mesh_0.face_vertices(0)
      assert 0 not in mesh_0.face_vertices(0)
      assert 0 in mesh_0.face_vertices(1)
      assert 4 not in mesh_0.face_vertices(1)
new_contents: import pytest
  
  import compas
  
  from compas.datastructures import Mesh
  from compas.datastructures import mesh_insert_vertex_on_edge
  from compas.datastructures import mesh_substitute_vertex_in_faces
  
  
  @pytest.fixture
  def mesh_0():
      vertices = [
          [1.0, 0.0, 0.0], 
          [1.0, 2.0, 0.0],
          [0.0, 1.0, 0.0],
          [2.0, 1.0, 0.0],
          [0.0, 0.0, 0.0]
      ]
      faces = [
          [0, 1, 2],
          [0, 3, 1]
      ]
      
      return Mesh.from_vertices_and_faces(vertices, faces)
  
  
  def test_insert_vertex_on_edge(mesh_0):
      mesh_insert_vertex_on_edge(mesh_0, 0, 1)
      assert len(mesh_0.face_vertices(0)) == 4
      assert len(mesh_0.face_vertices(1)) == 4
      assert mesh_0.face_vertex_descendant(0, 0) == 5
      assert mesh_0.face_vertex_descendant(1, 1) == 5
  
      mesh_insert_vertex_on_edge(mesh_0, 0, 2, 4)
      assert mesh_0.face_degree(0) == 5
      assert mesh_0.face_vertex_descendant(0, 2) == 4
  
  
  def test_mesh_substitute_vertex_in_faces(mesh_0):
      mesh_substitute_vertex_in_faces(mesh_0, 0, 4)
      assert 4 in mesh_0.face_vertices(0)
      assert 0 not in mesh_0.face_vertices(0)
      assert 4 in mesh_0.face_vertices(1)
      assert 0 not in mesh_0.face_vertices(1)
      mesh_substitute_vertex_in_faces(mesh_0, 4, 0, 1)
      assert 4 in mesh_0.face_vertices(0)
      assert 0 not in mesh_0.face_vertices(0)
      assert 0 in mesh_0.face_vertices(1)
      assert 4 not in mesh_0.face_vertices(1)
subject: fix test mesh insert vertex