Pillow/Tests/test_tiff_ifdrational.py
Jon Dufresne 4f185329f4 Streamline test skipping based on supported features
This adds a new test decorator: skip_unless_feature(). The argument is
the same as passed to features.check(). If the feature is not supported,
the test will be skipped.

This removes several kinds of boilerplate copied and pasted around tests
so test feature checking is handled and displayed more consistently.

Refs #4193
2020-02-18 13:07:01 -08:00

61 lines
1.7 KiB
Python

from fractions import Fraction
from PIL import Image, TiffImagePlugin, features
from PIL.TiffImagePlugin import IFDRational
from .helper import PillowTestCase, hopper
class Test_IFDRational(PillowTestCase):
def _test_equal(self, num, denom, target):
t = IFDRational(num, denom)
self.assertEqual(target, t)
self.assertEqual(t, target)
def test_sanity(self):
self._test_equal(1, 1, 1)
self._test_equal(1, 1, Fraction(1, 1))
self._test_equal(2, 2, 1)
self._test_equal(1.0, 1, Fraction(1, 1))
self._test_equal(Fraction(1, 1), 1, Fraction(1, 1))
self._test_equal(IFDRational(1, 1), 1, 1)
self._test_equal(1, 2, Fraction(1, 2))
self._test_equal(1, 2, IFDRational(1, 2))
def test_nonetype(self):
# Fails if the _delegate function doesn't return a valid function
xres = IFDRational(72)
yres = IFDRational(72)
self.assertIsNotNone(xres._val)
self.assertIsNotNone(xres.numerator)
self.assertIsNotNone(xres.denominator)
self.assertIsNotNone(yres._val)
self.assertTrue(xres and 1)
self.assertTrue(xres and yres)
def test_ifd_rational_save(self):
methods = (True, False)
if not features.check("libtiff"):
methods = (False,)
for libtiff in methods:
TiffImagePlugin.WRITE_LIBTIFF = libtiff
im = hopper()
out = self.tempfile("temp.tiff")
res = IFDRational(301, 1)
im.save(out, dpi=(res, res), compression="raw")
with Image.open(out) as reloaded:
self.assertEqual(
float(IFDRational(301, 1)), float(reloaded.tag_v2[282])
)