Pillow/Tests/test_pickle.py

import pickle

import pytest

from PIL import Image, ImageDraw, ImageFont

from .helper import assert_image_equal, skip_unless_feature

FONT_SIZE = 20
FONT_PATH = "Tests/fonts/DejaVuSans/DejaVuSans.ttf"


def helper_pickle_file(tmp_path, pickle, protocol, test_file, mode):
    # Arrange
    with Image.open(test_file) as im:
        filename = str(tmp_path / "temp.pkl")
        if mode:
            im = im.convert(mode)

        # Act
        with open(filename, "wb") as f:
            pickle.dump(im, f, protocol)
        with open(filename, "rb") as f:
            loaded_im = pickle.load(f)

        # Assert
        assert im == loaded_im


def helper_pickle_string(pickle, protocol, test_file, mode):
    with Image.open(test_file) as im:
        if mode:
            im = im.convert(mode)

        # Act
        dumped_string = pickle.dumps(im, protocol)
        loaded_im = pickle.loads(dumped_string)

        # Assert
        assert im == loaded_im


@pytest.mark.parametrize(
    ("test_file", "test_mode"),
    [
        ("Tests/images/hopper.jpg", None),
        ("Tests/images/hopper.jpg", "L"),
        ("Tests/images/hopper.jpg", "PA"),
        pytest.param(
            "Tests/images/hopper.webp", None, marks=skip_unless_feature("webp")
        ),
        ("Tests/images/hopper.tif", None),
        ("Tests/images/test-card.png", None),
        ("Tests/images/zero_bb.png", None),
        ("Tests/images/zero_bb_scale2.png", None),
        ("Tests/images/non_zero_bb.png", None),
        ("Tests/images/non_zero_bb_scale2.png", None),
        ("Tests/images/p_trns_single.png", None),
        ("Tests/images/pil123p.png", None),
        ("Tests/images/itxt_chunks.png", None),
    ],
)
def test_pickle_image(tmp_path, test_file, test_mode):
    # Act / Assert
    for protocol in range(0, pickle.HIGHEST_PROTOCOL + 1):
        helper_pickle_string(pickle, protocol, test_file, test_mode)
        helper_pickle_file(tmp_path, pickle, protocol, test_file, test_mode)


def test_pickle_la_mode_with_palette(tmp_path):
    # Arrange
    filename = str(tmp_path / "temp.pkl")
    with Image.open("Tests/images/hopper.jpg") as im:
        im = im.convert("PA")

    # Act / Assert
    for protocol in range(0, pickle.HIGHEST_PROTOCOL + 1):
        im.mode = "LA"
        with open(filename, "wb") as f:
            pickle.dump(im, f, protocol)
        with open(filename, "rb") as f:
            loaded_im = pickle.load(f)

        im.mode = "PA"
        assert im == loaded_im


@skip_unless_feature("webp")
def test_pickle_tell():
    # Arrange
    image = Image.open("Tests/images/hopper.webp")

    # Act: roundtrip
    unpickled_image = pickle.loads(pickle.dumps(image))

    # Assert
    assert unpickled_image.tell() == 0


def helper_assert_pickled_font_images(font1, font2):
    # Arrange
    im1 = Image.new(mode="RGBA", size=(300, 100))
    im2 = Image.new(mode="RGBA", size=(300, 100))
    draw1 = ImageDraw.Draw(im1)
    draw2 = ImageDraw.Draw(im2)
    txt = "Hello World!"

    # Act
    draw1.text((10, 10), txt, font=font1)
    draw2.text((10, 10), txt, font=font2)

    # Assert
    assert_image_equal(im1, im2)


@pytest.mark.parametrize("protocol", list(range(0, pickle.HIGHEST_PROTOCOL + 1)))
def test_pickle_font_string(protocol):
    # Arrange
    font = ImageFont.truetype(FONT_PATH, FONT_SIZE)

    # Act: roundtrip
    pickled_font = pickle.dumps(font, protocol)
    unpickled_font = pickle.loads(pickled_font)

    # Assert
    helper_assert_pickled_font_images(font, unpickled_font)


@pytest.mark.parametrize("protocol", list(range(0, pickle.HIGHEST_PROTOCOL + 1)))
def test_pickle_font_file(tmp_path, protocol):
    # Arrange
    font = ImageFont.truetype(FONT_PATH, FONT_SIZE)
    filename = str(tmp_path / "temp.pkl")

    # Act: roundtrip
    with open(filename, "wb") as f:
        pickle.dump(font, f, protocol)
    with open(filename, "rb") as f:
        unpickled_font = pickle.load(f)

    # Assert
    helper_assert_pickled_font_images(font, unpickled_font)