Pillow

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from __future__ import annotations
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from pathlib import Path
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from typing import IO
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import pytest
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from PIL import GribStubImagePlugin, Image, ImageFile
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from .helper import hopper
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TEST_FILE = "Tests/images/WAlaska.wind.7days.grb"
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def test_open() -> None:
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    # Act
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    with Image.open(TEST_FILE) as im:
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        # Assert
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        assert im.format == "GRIB"
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        # Dummy data from the stub
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        assert im.mode == "F"
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        assert im.size == (1, 1)
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def test_invalid_file() -> None:
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    # Arrange
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    invalid_file = "Tests/images/flower.jpg"
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    # Act / Assert
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    with pytest.raises(SyntaxError):
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        GribStubImagePlugin.GribStubImageFile(invalid_file)
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def test_load() -> None:
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    # Arrange
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    with Image.open(TEST_FILE) as im:
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        # Act / Assert: stub cannot load without an implemented handler
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        with pytest.raises(OSError):
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            im.load()
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def test_save(tmp_path: Path) -> None:
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    # Arrange
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    im = hopper()
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    tmpfile = str(tmp_path / "temp.grib")
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    # Act / Assert: stub cannot save without an implemented handler
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    with pytest.raises(OSError):
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        im.save(tmpfile)
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def test_handler(tmp_path: Path) -> None:
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    class TestHandler(ImageFile.StubHandler):
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        opened = False
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        loaded = False
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        saved = False
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        def open(self, im: Image.Image) -> None:
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            self.opened = True
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        def load(self, im: Image.Image) -> Image.Image:
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            self.loaded = True
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            im.fp.close()
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            return Image.new("RGB", (1, 1))
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        def is_loaded(self) -> bool:
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            return self.loaded
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        def save(self, im: Image.Image, fp: IO[bytes], filename: str) -> None:
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            self.saved = True
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    handler = TestHandler()
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    GribStubImagePlugin.register_handler(handler)
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    with Image.open(TEST_FILE) as im:
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        assert handler.opened
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        assert not handler.is_loaded()
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        im.load()
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        assert handler.is_loaded()
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        temp_file = str(tmp_path / "temp.grib")
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        im.save(temp_file)
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        assert handler.saved
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    GribStubImagePlugin._handler = None
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