Pillow/Tests/test_file_eps.py
Jon Dufresne 4cd4adddc3 Improve handling of file resources
Follow Python's file object semantics. User code is responsible for
closing resources (usually through a context manager) in a deterministic
way.

To achieve this, remove __del__ functions. These functions used to
closed open file handlers in an attempt to silence Python
ResourceWarnings. However, using __del__ has the following drawbacks:

- __del__ isn't called until the object's reference count reaches 0.
  Therefore, resource handlers remain open or in use longer than
  necessary.

- The __del__ method isn't guaranteed to execute on system exit. See the
  Python documentation:

  https://docs.python.org/3/reference/datamodel.html#object.__del__

  > It is not guaranteed that __del__() methods are called for objects
  > that still exist when the interpreter exits.

- Exceptions that occur inside __del__ are ignored instead of raised.
  This has the potential of hiding bugs. This is also in the Python
  documentation:

  > Warning: Due to the precarious circumstances under which __del__()
  > methods are invoked, exceptions that occur during their execution
  > are ignored, and a warning is printed to sys.stderr instead.

Instead, always close resource handlers when they are no longer in use.
This will close the file handler at a specified point in the user's code
and not wait until the interpreter chooses to. It is always guaranteed
to run. And, if an exception occurs while closing the file handler, the
bug will not be ignored.

Now, when code receives a ResourceWarning, it will highlight an area
that is mishandling resources. It should not simply be silenced, but
fixed by closing resources with a context manager.

All warnings that were emitted during tests have been cleaned up. To
enable warnings, I passed the `-Wa` CLI option to Python. This exposed
some mishandling of resources in ImageFile.__init__() and
SpiderImagePlugin.loadImageSeries(), they too were fixed.
2019-10-12 08:27:17 -07:00

241 lines
9.1 KiB
Python

import io
from PIL import EpsImagePlugin, Image
from .helper import PillowTestCase, hopper, unittest
HAS_GHOSTSCRIPT = EpsImagePlugin.has_ghostscript()
# Our two EPS test files (they are identical except for their bounding boxes)
file1 = "Tests/images/zero_bb.eps"
file2 = "Tests/images/non_zero_bb.eps"
# Due to palletization, we'll need to convert these to RGB after load
file1_compare = "Tests/images/zero_bb.png"
file1_compare_scale2 = "Tests/images/zero_bb_scale2.png"
file2_compare = "Tests/images/non_zero_bb.png"
file2_compare_scale2 = "Tests/images/non_zero_bb_scale2.png"
# EPS test files with binary preview
file3 = "Tests/images/binary_preview_map.eps"
class TestFileEps(PillowTestCase):
@unittest.skipUnless(HAS_GHOSTSCRIPT, "Ghostscript not available")
def test_sanity(self):
# Regular scale
with Image.open(file1) as image1:
image1.load()
self.assertEqual(image1.mode, "RGB")
self.assertEqual(image1.size, (460, 352))
self.assertEqual(image1.format, "EPS")
with Image.open(file2) as image2:
image2.load()
self.assertEqual(image2.mode, "RGB")
self.assertEqual(image2.size, (360, 252))
self.assertEqual(image2.format, "EPS")
# Double scale
with Image.open(file1) as image1_scale2:
image1_scale2.load(scale=2)
self.assertEqual(image1_scale2.mode, "RGB")
self.assertEqual(image1_scale2.size, (920, 704))
self.assertEqual(image1_scale2.format, "EPS")
with Image.open(file2) as image2_scale2:
image2_scale2.load(scale=2)
self.assertEqual(image2_scale2.mode, "RGB")
self.assertEqual(image2_scale2.size, (720, 504))
self.assertEqual(image2_scale2.format, "EPS")
def test_invalid_file(self):
invalid_file = "Tests/images/flower.jpg"
self.assertRaises(SyntaxError, EpsImagePlugin.EpsImageFile, invalid_file)
@unittest.skipUnless(HAS_GHOSTSCRIPT, "Ghostscript not available")
def test_cmyk(self):
with Image.open("Tests/images/pil_sample_cmyk.eps") as cmyk_image:
self.assertEqual(cmyk_image.mode, "CMYK")
self.assertEqual(cmyk_image.size, (100, 100))
self.assertEqual(cmyk_image.format, "EPS")
cmyk_image.load()
self.assertEqual(cmyk_image.mode, "RGB")
if "jpeg_decoder" in dir(Image.core):
target = Image.open("Tests/images/pil_sample_rgb.jpg")
self.assert_image_similar(cmyk_image, target, 10)
@unittest.skipUnless(HAS_GHOSTSCRIPT, "Ghostscript not available")
def test_showpage(self):
# See https://github.com/python-pillow/Pillow/issues/2615
with Image.open("Tests/images/reqd_showpage.eps") as plot_image:
with Image.open("Tests/images/reqd_showpage.png") as target:
# should not crash/hang
plot_image.load()
# fonts could be slightly different
self.assert_image_similar(plot_image, target, 6)
@unittest.skipUnless(HAS_GHOSTSCRIPT, "Ghostscript not available")
def test_file_object(self):
# issue 479
with Image.open(file1) as image1:
with open(self.tempfile("temp_file.eps"), "wb") as fh:
image1.save(fh, "EPS")
@unittest.skipUnless(HAS_GHOSTSCRIPT, "Ghostscript not available")
def test_iobase_object(self):
# issue 479
with Image.open(file1) as image1:
with io.open(self.tempfile("temp_iobase.eps"), "wb") as fh:
image1.save(fh, "EPS")
@unittest.skipUnless(HAS_GHOSTSCRIPT, "Ghostscript not available")
def test_bytesio_object(self):
with open(file1, "rb") as f:
img_bytes = io.BytesIO(f.read())
img = Image.open(img_bytes)
img.load()
image1_scale1_compare = Image.open(file1_compare).convert("RGB")
image1_scale1_compare.load()
self.assert_image_similar(img, image1_scale1_compare, 5)
def test_image_mode_not_supported(self):
im = hopper("RGBA")
tmpfile = self.tempfile("temp.eps")
self.assertRaises(ValueError, im.save, tmpfile)
@unittest.skipUnless(HAS_GHOSTSCRIPT, "Ghostscript not available")
def test_render_scale1(self):
# We need png support for these render test
codecs = dir(Image.core)
if "zip_encoder" not in codecs or "zip_decoder" not in codecs:
self.skipTest("zip/deflate support not available")
# Zero bounding box
with Image.open(file1) as image1_scale1:
image1_scale1.load()
image1_scale1_compare = Image.open(file1_compare).convert("RGB")
image1_scale1_compare.load()
self.assert_image_similar(image1_scale1, image1_scale1_compare, 5)
# Non-Zero bounding box
with Image.open(file2) as image2_scale1:
image2_scale1.load()
image2_scale1_compare = Image.open(file2_compare).convert("RGB")
image2_scale1_compare.load()
self.assert_image_similar(image2_scale1, image2_scale1_compare, 10)
@unittest.skipUnless(HAS_GHOSTSCRIPT, "Ghostscript not available")
def test_render_scale2(self):
# We need png support for these render test
codecs = dir(Image.core)
if "zip_encoder" not in codecs or "zip_decoder" not in codecs:
self.skipTest("zip/deflate support not available")
# Zero bounding box
with Image.open(file1) as image1_scale2:
image1_scale2.load(scale=2)
image1_scale2_compare = Image.open(file1_compare_scale2).convert("RGB")
image1_scale2_compare.load()
self.assert_image_similar(image1_scale2, image1_scale2_compare, 5)
# Non-Zero bounding box
with Image.open(file2) as image2_scale2:
image2_scale2.load(scale=2)
image2_scale2_compare = Image.open(file2_compare_scale2).convert("RGB")
image2_scale2_compare.load()
self.assert_image_similar(image2_scale2, image2_scale2_compare, 10)
@unittest.skipUnless(HAS_GHOSTSCRIPT, "Ghostscript not available")
def test_resize(self):
files = [file1, file2, "Tests/images/illu10_preview.eps"]
for fn in files:
with Image.open(fn) as im:
new_size = (100, 100)
im = im.resize(new_size)
self.assertEqual(im.size, new_size)
@unittest.skipUnless(HAS_GHOSTSCRIPT, "Ghostscript not available")
def test_thumbnail(self):
# Issue #619
# Arrange
files = [file1, file2]
for fn in files:
with Image.open(file1) as im:
new_size = (100, 100)
im.thumbnail(new_size)
self.assertEqual(max(im.size), max(new_size))
def test_read_binary_preview(self):
# Issue 302
# open image with binary preview
with Image.open(file3):
pass
def _test_readline(self, t, ending):
ending = "Failure with line ending: %s" % (
"".join("%s" % ord(s) for s in ending)
)
self.assertEqual(t.readline().strip("\r\n"), "something", ending)
self.assertEqual(t.readline().strip("\r\n"), "else", ending)
self.assertEqual(t.readline().strip("\r\n"), "baz", ending)
self.assertEqual(t.readline().strip("\r\n"), "bif", ending)
def _test_readline_io_psfile(self, test_string, ending):
f = io.BytesIO(test_string.encode("latin-1"))
t = EpsImagePlugin.PSFile(f)
self._test_readline(t, ending)
def _test_readline_file_psfile(self, test_string, ending):
f = self.tempfile("temp.txt")
with open(f, "wb") as w:
w.write(test_string.encode("latin-1"))
with open(f, "rb") as r:
t = EpsImagePlugin.PSFile(r)
self._test_readline(t, ending)
def test_readline(self):
# check all the freaking line endings possible from the spec
# test_string = u'something\r\nelse\n\rbaz\rbif\n'
line_endings = ["\r\n", "\n", "\n\r", "\r"]
strings = ["something", "else", "baz", "bif"]
for ending in line_endings:
s = ending.join(strings)
self._test_readline_io_psfile(s, ending)
self._test_readline_file_psfile(s, ending)
def test_open_eps(self):
# https://github.com/python-pillow/Pillow/issues/1104
# Arrange
FILES = [
"Tests/images/illu10_no_preview.eps",
"Tests/images/illu10_preview.eps",
"Tests/images/illuCS6_no_preview.eps",
"Tests/images/illuCS6_preview.eps",
]
# Act / Assert
for filename in FILES:
with Image.open(filename) as img:
self.assertEqual(img.mode, "RGB")
@unittest.skipUnless(HAS_GHOSTSCRIPT, "Ghostscript not available")
def test_emptyline(self):
# Test file includes an empty line in the header data
emptyline_file = "Tests/images/zero_bb_emptyline.eps"
with Image.open(emptyline_file) as image:
image.load()
self.assertEqual(image.mode, "RGB")
self.assertEqual(image.size, (460, 352))
self.assertEqual(image.format, "EPS")