Convert tesseract_badutf8 to plugin

tests/plugins/tesseract_badutf8.py

@@ -0,0 +1,63 @@
+# © 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.
+# IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+# CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+# TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+# SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+"""Tesseract bad utf8
+
+In some cases, some versions of Tesseract can output binary gibberish or data
+that is not UTF-8 compatible, so we are forced to check that we can convert it
+and present it to the user.
+"""
+
+from subprocess import CalledProcessError
+from unittest.mock import patch
+
+from ocrmypdf import hookimpl
+from ocrmypdf.builtin_plugins.tesseract_ocr import TesseractOcrEngine
+
+
+def bad_utf8(*args, **kwargs):
+    raise CalledProcessError(
+        1,
+        'tesseract',
+        output=b'\x96\xb3\x8c\xf8\x82\xc8UTF-8\x0a',  # "Invalid UTF-8" in Shift JIS
+        stderr=b"",
+    )
+
+
+class BadUtf8OcrEngine(TesseractOcrEngine):
+    @staticmethod
+    def generate_hocr(input_file, output_hocr, output_text, options):
+        with patch('ocrmypdf.exec.tesseract.run', new=bad_utf8):
+            TesseractOcrEngine.generate_hocr(
+                input_file, output_hocr, output_text, options
+            )
+
+    @staticmethod
+    def generate_pdf(input_file, output_pdf, output_text, options):
+        with patch('ocrmypdf.exec.tesseract.run', new=bad_utf8):
+            TesseractOcrEngine.generate_pdf(
+                input_file, output_pdf, output_text, options
+            )
+
+
+@hookimpl
+def get_ocr_engine():
+    return BadUtf8OcrEngine()