old_contents: import pytest
  
  from pip._internal.commands import commands_dict, create_command
  
  
  def test_commands_dict__order():
      """
      Check the ordering of commands_dict.
      """
      names = list(commands_dict)
      # A spot-check is sufficient to check that commands_dict encodes an
      # ordering.
      assert names[0] == 'install'
      assert names[-1] == 'help'
  
  
  @pytest.mark.parametrize('name', list(commands_dict))
  def test_create_command(name):
      """Test creating an instance of each available command."""
      command = create_command(name)
      assert command.name == name
      assert command.summary == commands_dict[name].summary
  
new_contents: import pytest
  
  from pip._internal.cli.req_command import (
      IndexGroupCommand,
      RequirementCommand,
      SessionCommandMixin,
  )
  from pip._internal.commands import commands_dict, create_command
  
  
  def check_commands(pred, expected):
      """
      Check the commands satisfying a predicate.
      """
      commands = [create_command(name) for name in sorted(commands_dict)]
      actual = [command.name for command in commands if pred(command)]
      assert actual == expected, 'actual: {}'.format(actual)
  
  
  def test_commands_dict__order():
      """
      Check the ordering of commands_dict.
      """
      names = list(commands_dict)
      # A spot-check is sufficient to check that commands_dict encodes an
      # ordering.
      assert names[0] == 'install'
      assert names[-1] == 'help'
  
  
  @pytest.mark.parametrize('name', list(commands_dict))
  def test_create_command(name):
      """Test creating an instance of each available command."""
      command = create_command(name)
      assert command.name == name
      assert command.summary == commands_dict[name].summary
  
  
  def test_session_commands():
      """
      Test which commands inherit from SessionCommandMixin.
      """
      def is_session_command(command):
          return isinstance(command, SessionCommandMixin)
  
      expected = ['download', 'install', 'list', 'search', 'uninstall', 'wheel']
      check_commands(is_session_command, expected)
  
  
  def test_index_group_commands():
      """
      Test the commands inheriting from IndexGroupCommand.
      """
      expected = ['download', 'install', 'list', 'wheel']
  
      def is_index_group_command(command):
          return isinstance(command, IndexGroupCommand)
  
      check_commands(is_index_group_command, expected)
  
      # Also check that the commands inheriting from IndexGroupCommand are
      # exactly the commands with the --no-index option.
      def has_option_no_index(command):
          return command.parser.has_option('--no-index')
  
      check_commands(has_option_no_index, expected)
  
  
  def test_requirement_commands():
      """
      Test which commands inherit from RequirementCommand.
      """
      def is_requirement_command(command):
          return isinstance(command, RequirementCommand)
  
      check_commands(is_requirement_command, ['download', 'install', 'wheel'])
  
subject: Test the command class inheritance for each command.