code: def test_formats(tmpdir):
      tmpdir.join(".jupytext").write(
          '''# Default pairing
  formats = "ipynb,py"'''
      )
      test = tmpdir.join("test.py")
      test.write("1 + 1\n")
  
      jupytext([str(test), "--sync"])
  
      assert tmpdir.join("test.ipynb").isfile()
  
file_path: jupytext/tests/functional/cli/test_cli_config.py
imports: import nbformat
  import pytest
  from nbformat.v4.nbbase import new_code_cell, new_notebook
  from jupytext.cli import jupytext
  from jupytext.compare import compare
  from jupytext.header import header_to_metadata_and_cell
  from jupytext.jupytext import read, write
label_desc: Use image node_id 2 for calling a global function with example usage: test_formats(tmpdir) without return types