code: def test_check_environment_and_redirect(
      mock_redirect_command, tmpdir, monkeypatch
  ):
      # Ensure that the test fails if it tries to redirect
      mock_redirect_command.side_effect = RuntimeError
  
      # Test normal executable on the path
      # Ensure current executable is on the path
      monkeypatch.setenv("PATH", f"{os.path.dirname(sys.executable)}")
  
      assert _check_environment_and_redirect() is None
  
      # Test executable on the path with redirect
      fake_python_path = os.path.join(tmpdir, "python")
  
      os.symlink(sys.executable, fake_python_path)
  
      monkeypatch.setenv("PATH", f"{tmpdir}")
      assert _check_environment_and_redirect() is None
  
      os.remove(fake_python_path)
  
      descriptor = os.open(
          fake_python_path,
          flags=(
              os.O_WRONLY  # access mode: write only
              | os.O_CREAT  # create if not exists
              | os.O_TRUNC  # truncate the file to zero
          ),
          mode=0o777,
      )
  
      with open(descriptor, "w") as f:
          f.writelines(
              [
                  "#!/bin/bash\n",
                  f'{sys.executable} "$@"',
              ]
          )
  
      monkeypatch.setenv("PATH", f"{tmpdir}")
      assert _check_environment_and_redirect() is None
  
file_path: pytorch-lightning/tests/tests_app/utilities/test_cli_helpers.py
imports: import os
  import sys
  from unittest.mock import Mock, patch
  import arrow
  import lightning.app
  import pytest
  from lightning.app.utilities.cli_helpers import _arrow_time_callback, _check_environment_and_redirect, _format_input_env_variables, _get_newer_version
label_desc: Use image node_id 4 for calling a global function with example usage: test_check_environment_and_redirect(mock_redirect_command, tmpdir, monkeypatch) without return types