OCRmyPDF/tests/plugins/tesseract_big_image_error.py

# © 2020 James R. Barlow: github.com/jbarlow83
#
# Permission is hereby granted, free of charge, to any person obtaining a
# copy of this software and associated documentation files (the
# "Software"), to deal in the Software without restriction, including
# without limitation the rights to use, copy, modify, merge, publish,
# distribute, sublicense, and/or sell copies of the Software, and to
# permit persons to whom the Software is furnished to do so, subject to
# the following conditions:
#
# The above copyright notice and this permission notice shall be included
# in all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
# OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
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from contextlib import contextmanager
from subprocess import CalledProcessError
from unittest.mock import patch

from ocrmypdf import hookimpl
from ocrmypdf.builtin_plugins.tesseract_ocr import TesseractOcrEngine


def raise_size_exception(*args, **kwargs):
    raise CalledProcessError(
        1,
        'tesseract',
        output=b"Image too large: (33830, 14959)\nError during processing.",
        stderr=b"",
    )


@contextmanager
def patch_tesseract_run():
    with patch('ocrmypdf._exec.tesseract.run') as mock:
        mock.side_effect = raise_size_exception
        yield
        mock.assert_called()


class BigImageErrorOcrEngine(TesseractOcrEngine):
    @staticmethod
    def get_orientation(input_file, options):
        with patch_tesseract_run():
            return TesseractOcrEngine.get_orientation(input_file, options)

    @staticmethod
    def generate_hocr(input_file, output_hocr, output_text, options):
        with patch_tesseract_run():
            TesseractOcrEngine.generate_hocr(
                input_file, output_hocr, output_text, options
            )

    @staticmethod
    def generate_pdf(input_file, output_pdf, output_text, options):
        with patch_tesseract_run():
            TesseractOcrEngine.generate_pdf(
                input_file, output_pdf, output_text, options
            )


@hookimpl
def get_ocr_engine():
    return BigImageErrorOcrEngine()