old_contents: import os
  
  from .. import run_python_module, run_command
  from .base import BaseTestApp
  
  
  class TestNbGrader(BaseTestApp):
  
      def test_help(self):
          """Does the help display without error?"""
          run_python_module(["nbgrader", "--help-all"])
  
      def test_no_subapp(self):
          """Is the help displayed when no subapp is given?"""
          run_python_module(["nbgrader"], retcode=1)
  
      def test_generate_config(self):
          """Is the config file properly generated?"""
  
          # it already exists, because we create it in conftest.py
          os.remove("nbgrader_config.py")
  
          # try recreating it
          run_python_module(["nbgrader", "--generate-config"])
          assert os.path.isfile("nbgrader_config.py")
  
          # does it fail if it already exists?
          run_python_module(["nbgrader", "--generate-config"], retcode=1)
  
      def test_check_version(self):
          """Is the version the same regardless of how we run nbgrader?"""
          out1 = run_command(["nbgrader", "--version"])
          out2 = run_python_module(["nbgrader", "--version"])
          assert out1 == out2
  
new_contents: import os
  import sys
  
  from .. import run_python_module, run_command
  from .base import BaseTestApp
  
  
  class TestNbGrader(BaseTestApp):
  
      def test_help(self):
          """Does the help display without error?"""
          run_python_module(["nbgrader", "--help-all"])
  
      def test_no_subapp(self):
          """Is the help displayed when no subapp is given?"""
          run_python_module(["nbgrader"], retcode=1)
  
      def test_generate_config(self):
          """Is the config file properly generated?"""
  
          # it already exists, because we create it in conftest.py
          os.remove("nbgrader_config.py")
  
          # try recreating it
          run_python_module(["nbgrader", "--generate-config"])
          assert os.path.isfile("nbgrader_config.py")
  
          # does it fail if it already exists?
          run_python_module(["nbgrader", "--generate-config"], retcode=1)
  
      def test_check_version(self):
          """Is the version the same regardless of how we run nbgrader?"""
          if sys.platform == 'win32':
              out1 = "\r\n".join(run_command(["nbgrader.cmd", "--version"]).split("\r\n")[2:])
          else:
              out1 = run_command(["nbgrader", "--version"])
          out2 = run_python_module(["nbgrader", "--version"])
          assert out1 == out2
  
subject: Fix issue with how nbgrader is called