code: def test_stdin(ocrmypdf_exec, resources, outpdf):
      input_file = str(resources / "francais.pdf")
      output_file = str(outpdf)
  
      # Runs: ocrmypdf - output.pdf < testfile.pdf
      with open(input_file, "rb") as input_stream:
          p_args = ocrmypdf_exec + [
              "-",
              output_file,
              "--plugin",
              "tests/plugins/tesseract_noop.py",
          ]
          run(
              p_args,
              capture_output=True,
              stdin=input_stream,
              check=True,
          )
  
file_path: OCRmyPDF/tests/test_stdio.py
imports: from __future__ import annotations
  import os
  from subprocess import DEVNULL, PIPE, run
  import pytest
  from ocrmypdf.helpers import check_pdf
  from .conftest import run_ocrmypdf
label_desc: Use image node_id 1 for calling a global function with example usage: test_stdin(ocrmypdf_exec, resources, outpdf) without return types