tests: add type hints

Signed-off-by: Benjamin Gilbert <bgilbert@cs.cmu.edu>

Author: bgilbert

.pre-commit-config.yaml

@@ -59,7 +59,7 @@ repos:
       - id: mypy
         name: Check Python types
         additional_dependencies: [openslide-bin, pillow, types-setuptools]
-        exclude: "^(doc/.*|tests/.*|examples/deepzoom/.*)$"
+        exclude: "^(doc/.*|examples/deepzoom/.*)$"
 
   - repo: https://github.com/rstcheck/rstcheck
     rev: v6.2.4

tests/common.py

@@ -30,9 +30,9 @@
     # environment.
     _dll_path = os.getenv('OPENSLIDE_PATH')
     if _dll_path is not None:
-        with os.add_dll_directory(_dll_path):
+        with os.add_dll_directory(_dll_path):  # type: ignore[attr-defined]
             import openslide  # noqa: F401  module-imported-but-unused
 
 
-def file_path(name):
+def file_path(name: str) -> Path:
     return Path(__file__).parent / 'fixtures' / name

tests/test_base.py

@@ -28,13 +28,13 @@
 
 
 class TestLibrary(unittest.TestCase):
-    def test_open_slide(self):
+    def test_open_slide(self) -> None:
         with open_slide(file_path('boxes.tiff')) as osr:
             self.assertTrue(isinstance(osr, OpenSlide))
         with open_slide(file_path('boxes.png')) as osr:
             self.assertTrue(isinstance(osr, ImageSlide))
 
-    def test_lowlevel_available(self):
+    def test_lowlevel_available(self) -> None:
         '''Ensure all exported functions have an 'available' attribute.'''
         for name in dir(lowlevel):
             attr = getattr(lowlevel, name)

tests/test_deepzoom.py

@@ -30,24 +30,26 @@
 class _Abstract:
     # nested class to prevent the test runner from finding it
     class BoxesDeepZoomTest(unittest.TestCase):
-        def setUp(self):
+        CLASS: type | None = None
+        FILENAME: str | None = None
+
+        def setUp(self) -> None:
+            assert self.CLASS is not None
+            assert self.FILENAME is not None
             self.osr = self.CLASS(file_path(self.FILENAME))
             self.dz = DeepZoomGenerator(self.osr, 254, 1)
 
-        def tearDown(self):
+        def tearDown(self) -> None:
             self.osr.close()
 
-        def test_repr(self):
+        def test_repr(self) -> None:
             self.assertEqual(
                 repr(self.dz),
-                (
-                    'DeepZoomGenerator(%r, tile_size=254, overlap=1, '
-                    + 'limit_bounds=False)'
-                )
+                'DeepZoomGenerator(%r, tile_size=254, overlap=1, limit_bounds=False)'
                 % self.osr,
             )
 
-        def test_metadata(self):
+        def test_metadata(self) -> None:
             self.assertEqual(self.dz.level_count, 10)
             self.assertEqual(self.dz.tile_count, 11)
             self.assertEqual(
@@ -81,31 +83,31 @@ def test_metadata(self):
                 ),
             )
 
-        def test_get_tile(self):
+        def test_get_tile(self) -> None:
             self.assertEqual(self.dz.get_tile(9, (1, 0)).size, (47, 250))
 
-        def test_tile_color_profile(self):
+        def test_tile_color_profile(self) -> None:
             if self.CLASS is OpenSlide and not lowlevel.read_icc_profile.available:
                 self.skipTest("requires OpenSlide 4.0.0")
             self.assertEqual(len(self.dz.get_tile(9, (1, 0)).info['icc_profile']), 588)
 
-        def test_get_tile_bad_level(self):
+        def test_get_tile_bad_level(self) -> None:
             self.assertRaises(ValueError, lambda: self.dz.get_tile(-1, (0, 0)))
             self.assertRaises(ValueError, lambda: self.dz.get_tile(10, (0, 0)))
 
-        def test_get_tile_bad_address(self):
+        def test_get_tile_bad_address(self) -> None:
             self.assertRaises(ValueError, lambda: self.dz.get_tile(0, (-1, 0)))
             self.assertRaises(ValueError, lambda: self.dz.get_tile(0, (1, 0)))
 
-        def test_get_tile_coordinates(self):
+        def test_get_tile_coordinates(self) -> None:
             self.assertEqual(
                 self.dz.get_tile_coordinates(9, (1, 0)), ((253, 0), 0, (47, 250))
             )
 
-        def test_get_tile_dimensions(self):
+        def test_get_tile_dimensions(self) -> None:
             self.assertEqual(self.dz.get_tile_dimensions(9, (1, 0)), (47, 250))
 
-        def test_get_dzi(self):
+        def test_get_dzi(self) -> None:
             self.assertTrue(
                 'http://schemas.microsoft.com/deepzoom/2008' in self.dz.get_dzi('jpeg')
             )

tests/test_imageslide.py

@@ -29,16 +29,16 @@
 
 
 class TestImageWithoutOpening(unittest.TestCase):
-    def test_detect_format(self):
+    def test_detect_format(self) -> None:
         self.assertTrue(ImageSlide.detect_format(file_path('__missing_file')) is None)
         self.assertTrue(ImageSlide.detect_format(file_path('../setup.py')) is None)
         self.assertEqual(ImageSlide.detect_format(file_path('boxes.png')), 'PNG')
 
-    def test_open(self):
+    def test_open(self) -> None:
         self.assertRaises(OSError, lambda: ImageSlide(file_path('__does_not_exist')))
         self.assertRaises(OSError, lambda: ImageSlide(file_path('../setup.py')))
 
-    def test_open_image(self):
+    def test_open_image(self) -> None:
         # passing PIL.Image to ImageSlide
         with Image.open(file_path('boxes.png')) as img:
             with ImageSlide(img) as osr:
@@ -49,18 +49,18 @@ def test_open_image(self):
         sys.getfilesystemencoding() == 'utf-8',
         'Python filesystem encoding is not UTF-8',
     )
-    def test_unicode_path(self):
+    def test_unicode_path(self) -> None:
         path = file_path('😐.png')
         for arg in path, str(path):
             self.assertEqual(ImageSlide.detect_format(arg), 'PNG')
             self.assertEqual(ImageSlide(arg).dimensions, (300, 250))
 
-    def test_unicode_path_bytes(self):
+    def test_unicode_path_bytes(self) -> None:
         arg = str(file_path('😐.png')).encode('UTF-8')
         self.assertEqual(ImageSlide.detect_format(arg), 'PNG')
         self.assertEqual(ImageSlide(arg).dimensions, (300, 250))
 
-    def test_operations_on_closed_handle(self):
+    def test_operations_on_closed_handle(self) -> None:
         with Image.open(file_path('boxes.png')) as img:
             osr = ImageSlide(img)
             osr.close()
@@ -72,7 +72,7 @@ def test_operations_on_closed_handle(self):
             # shouldn't close it
             self.assertEqual(img.getpixel((0, 0)), 3)
 
-    def test_context_manager(self):
+    def test_context_manager(self) -> None:
         osr = ImageSlide(file_path('boxes.png'))
         with osr:
             pass
@@ -83,20 +83,23 @@ def test_context_manager(self):
 class _Abstract:
     # nested class to prevent the test runner from finding it
     class SlideTest(unittest.TestCase):
-        def setUp(self):
+        FILENAME: str | None = None
+
+        def setUp(self) -> None:
+            assert self.FILENAME is not None
             self.osr = ImageSlide(file_path(self.FILENAME))
 
-        def tearDown(self):
+        def tearDown(self) -> None:
             self.osr.close()
 
 
 class TestImage(_Abstract.SlideTest):
     FILENAME = 'boxes.png'
 
-    def test_repr(self):
+    def test_repr(self) -> None:
         self.assertEqual(repr(self.osr), 'ImageSlide(%r)' % file_path('boxes.png'))
 
-    def test_metadata(self):
+    def test_metadata(self) -> None:
         self.assertEqual(self.osr.level_count, 1)
         self.assertEqual(self.osr.level_dimensions, ((300, 250),))
         self.assertEqual(self.osr.dimensions, (300, 250))
@@ -108,7 +111,8 @@ def test_metadata(self):
         self.assertEqual(self.osr.properties, {})
         self.assertEqual(self.osr.associated_images, {})
 
-    def test_color_profile(self):
+    def test_color_profile(self) -> None:
+        assert self.osr.color_profile is not None  # for type inference
         self.assertEqual(self.osr.color_profile.profile.device_class, 'mntr')
         self.assertEqual(
             len(self.osr.read_region((0, 0), 0, (100, 100)).info['icc_profile']), 588
@@ -117,37 +121,37 @@ def test_color_profile(self):
             len(self.osr.get_thumbnail((100, 100)).info['icc_profile']), 588
         )
 
-    def test_read_region(self):
+    def test_read_region(self) -> None:
         self.assertEqual(
             self.osr.read_region((-10, -10), 0, (400, 400)).size, (400, 400)
         )
 
-    def test_read_region_size_dimension_zero(self):
+    def test_read_region_size_dimension_zero(self) -> None:
         self.assertEqual(self.osr.read_region((0, 0), 0, (400, 0)).size, (400, 0))
 
-    def test_read_region_bad_level(self):
+    def test_read_region_bad_level(self) -> None:
         self.assertRaises(
             OpenSlideError, lambda: self.osr.read_region((0, 0), 1, (100, 100))
         )
 
-    def test_read_region_bad_size(self):
+    def test_read_region_bad_size(self) -> None:
         self.assertRaises(
             OpenSlideError, lambda: self.osr.read_region((0, 0), 0, (400, -5))
         )
 
-    def test_thumbnail(self):
+    def test_thumbnail(self) -> None:
         self.assertEqual(self.osr.get_thumbnail((100, 100)).size, (100, 83))
 
     @unittest.skipUnless(lowlevel.cache_create.available, "requires OpenSlide 4.0.0")
-    def test_set_cache(self):
+    def test_set_cache(self) -> None:
         self.osr.set_cache(OpenSlideCache(64 << 10))
         self.assertEqual(self.osr.read_region((0, 0), 0, (400, 400)).size, (400, 400))
 
 
 class TestNoIccImage(_Abstract.SlideTest):
     FILENAME = 'boxes-no-icc.png'
 
-    def test_color_profile(self):
+    def test_color_profile(self) -> None:
         self.assertIsNone(self.osr.color_profile)
         self.assertNotIn(
             'icc_profile', self.osr.read_region((0, 0), 0, (100, 100)).info