code: def test_no_scm(tmp_dir, dvc):
      from dvc.scm import NoSCMError
  
      tmp_dir.dvc_gen("file", "text")
  
      with pytest.raises(NoSCMError):
          dvc.diff()
  
imports: import hashlib
  import os
  import pytest
  from funcy import first
  from dvc.exceptions import DvcException
  from dvc.utils.fs import remove
label_desc: Use image node_id 2 for calling a global function with example usage: test_no_scm(tmp_dir, dvc) without return types