pdfinfo: improve the regex

tests/test_pdfinfo.py

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+# © 2015 James R. Barlow: github.com/jbarlow83
+#
+# This file is part of OCRmyPDF.
+#
+# OCRmyPDF is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# OCRmyPDF is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with OCRmyPDF.  If not, see <http://www.gnu.org/licenses/>.
+
+from ocrmypdf import pdfinfo
+from reportlab.pdfgen.canvas import Canvas
+from PIL import Image
+from tempfile import NamedTemporaryFile
+from math import isclose
+from ocrmypdf.pdfinfo import Colorspace, Encoding
+from contextlib import suppress
+import os
+import shutil
+import pytest
+import img2pdf
+import sys
+import PyPDF2 as pypdf
+import pikepdf
+import pickle
+
+
+def test_single_page_text(outdir):
+    filename = outdir / 'text.pdf'
+    pdf = Canvas(str(filename), pagesize=(8*72, 6*72))
+    text = pdf.beginText()
+    text.setFont('Helvetica', 12)
+    text.setTextOrigin(1*72, 3*72)
+    text.textLine("Methink'st thou art a general offence and every"
+                  " man should beat thee.")
+    pdf.drawText(text)
+    pdf.showPage()
+    pdf.save()
+
+    info = pdfinfo.PdfInfo(filename)
+
+    assert len(info) == 1
+    page = info[0]
+
+    assert page.has_text
+    assert len(page.images) == 0
+
+
+def test_single_page_image(outdir):
+    filename = outdir / 'image-mono.pdf'
+
+    im_tmp = outdir / 'tmp.png'
+    im = Image.new('1', (8, 8), 0)
+    for n in range(8):
+        im.putpixel((n, n), 1)
+    im.save(str(im_tmp), format='PNG')
+
+    imgsize = ((img2pdf.ImgSize.dpi, 8), (img2pdf.ImgSize.dpi, 8))
+    layout_fun = img2pdf.get_layout_fun(None, imgsize, None, None, None)
+
+    im_bytes = im_tmp.read_bytes()
+    pdf_bytes = img2pdf.convert(
+            im_bytes, producer="img2pdf", with_pdfrw=False,
+            layout_fun=layout_fun)
+    filename.write_bytes(pdf_bytes)
+
+    info = pdfinfo.PdfInfo(filename)
+
+    assert len(info) == 1
+    page = info[0]
+
+    assert not page.has_text
+    assert len(page.images) == 1
+
+    pdfimage = page.images[0]
+    assert pdfimage.width == 8
+    assert pdfimage.color == Colorspace.gray
+
+    # DPI in a 1"x1" is the image width
+    assert isclose(pdfimage.xres, 8)
+    assert isclose(pdfimage.yres, 8)
+
+
+def test_single_page_inline_image(outdir):
+    filename = outdir / 'image-mono-inline.pdf'
+    pdf = Canvas(str(filename), pagesize=(8*72, 6*72))
+    with NamedTemporaryFile() as im_tmp:
+        im = Image.new('1', (8, 8), 0)
+        for n in range(8):
+            im.putpixel((n, n), 1)
+        im.save(im_tmp.name, format='PNG')
+        # Draw image in a 72x72 pt or 1"x1" area
+        pdf.drawInlineImage(im_tmp.name, 0, 0, width=72, height=72)
+        pdf.showPage()
+        pdf.save()
+
+    pdf = pdfinfo.PdfInfo(filename)
+    print(pdf)
+    pdfimage = pdf[0].images[0]
+    assert isclose(pdfimage.xres, 8)
+    assert pdfimage.color == Colorspace.rgb  # reportlab produces color image
+    assert pdfimage.width == 8
+
+
+def test_jpeg(resources, outdir):
+    filename = resources / 'c02-22.pdf'
+
+    pdf = pdfinfo.PdfInfo(filename)
+
+    pdfimage = pdf[0].images[0]
+    assert pdfimage.enc == Encoding.jpeg
+    assert isclose(pdfimage.xres, 150)
+
+
+def test_form_xobject(resources):
+    filename = resources / 'formxobject.pdf'
+
+    pdf = pdfinfo.PdfInfo(filename)
+    pdfimage = pdf[0].images[0]
+    assert pdfimage.width == 50
+
+
+def test_no_contents(resources):
+    filename = resources / 'no_contents.pdf'
+
+    pdf = pdfinfo.PdfInfo(filename)
+    assert len(pdf[0].images) == 0
+    assert pdf[0].has_text == False
+
+
+def test_oversized_page(resources):
+    pdf = pdfinfo.PdfInfo(resources / 'poster.pdf')
+    image = pdf[0].images[0]
+    assert image.width * image.xres > 200, "this is supposed to be oversized"
+
+
+def test_pickle(resources):
+    # For multiprocessing we must be able to pickle our information - if
+    # this fails then we are probably storing some unpickleabe pikepdf or
+    # other external data around
+    filename = resources / 'formxobject.pdf'
+    pdf = pdfinfo.PdfInfo(filename)
+    pickle.dumps(pdf)
+
+
+def test_regex():
+    rx = pdfinfo.regex_remove_char_tags
+
+    must_match = [
+        b'<char bbox="0 108 0 108" c="/"/>',
+        b'<char bbox="0 108 0 108" c=">"/>',
+        b'<char bbox="0 108 0 108" c="X"/>',
+    ]
+    must_not_match = [
+        b'<span stuff="c">',
+        b'<span>',
+        b'</span>',
+        b'</page>'
+    ]
+
+    for s in must_match:
+        assert rx.match(s)
+    for s in must_not_match:
+        assert not rx.match(s)