Pillow/Tests/test_tiff_ifdrational.py
2024-09-09 22:34:46 +10:00

77 lines
1.9 KiB
Python

from __future__ import annotations
from fractions import Fraction
from pathlib import Path
import pytest
from PIL import Image, TiffImagePlugin
from PIL.TiffImagePlugin import IFDRational
from .helper import hopper, skip_unless_feature
def _test_equal(
num: float | Fraction | IFDRational,
denom: int,
target: float | Fraction | IFDRational,
) -> None:
t = IFDRational(num, denom)
assert target == t
assert t == target
def test_sanity() -> None:
_test_equal(1, 1, 1)
_test_equal(1, 1, Fraction(1, 1))
_test_equal(2, 2, 1)
_test_equal(1.0, 1, Fraction(1, 1))
_test_equal(Fraction(1, 1), 1, Fraction(1, 1))
_test_equal(IFDRational(1, 1), 1, 1)
_test_equal(1, 2, Fraction(1, 2))
_test_equal(1, 2, IFDRational(1, 2))
_test_equal(7, 5, 1.4)
def test_ranges() -> None:
for num in range(1, 10):
for denom in range(1, 10):
assert IFDRational(num, denom) == IFDRational(num, denom)
def test_nonetype() -> None:
# Fails if the _delegate function doesn't return a valid function
xres = IFDRational(72)
yres = IFDRational(72)
assert xres._val is not None
assert xres.numerator is not None
assert xres.denominator is not None
assert yres._val is not None
assert xres
assert yres
@pytest.mark.parametrize(
"libtiff", (pytest.param(True, marks=skip_unless_feature("libtiff")), False)
)
def test_ifd_rational_save(
monkeypatch: pytest.MonkeyPatch, tmp_path: Path, libtiff: bool
) -> None:
im = hopper()
out = str(tmp_path / "temp.tiff")
res = IFDRational(301, 1)
monkeypatch.setattr(TiffImagePlugin, "WRITE_LIBTIFF", libtiff)
im.save(out, dpi=(res, res), compression="raw")
with Image.open(out) as reloaded:
assert isinstance(reloaded, TiffImagePlugin.TiffImageFile)
assert float(IFDRational(301, 1)) == float(reloaded.tag_v2[282])