code: def test_read_simple_r(
      ext,
      text="""# This is a very simple R file
  # I expect to get three cells here.
  #
  # The first one is markdown. The two others
  # are code cells
  
  cars
  
  plot(cars)
  """,
  ):
      nb = jupytext.reads(text, ext)
      assert len(nb.cells) == 3
      assert nb.cells[0].cell_type == "markdown"
      assert nb.cells[1].cell_type == "code"
      assert nb.cells[2].cell_type == "code"
      assert nb.cells[1].source == "cars"
      assert nb.cells[2].source == "plot(cars)"
      text2 = jupytext.writes(nb, ext)
      compare(text2, text)
  
file_path: jupytext/tests/functional/simple_notebooks/test_read_simple_R.py
imports: import pytest
  import jupytext
  from jupytext.compare import compare
label_desc: Use image node_id 6 for calling a global function with example usage: test_read_simple_r(ext, text) without return types