tests: enhance test_get_pixels.py, and try to fix a random failure at the same time (#252)

Author: BoboTiG

CHANGELOG.md

@@ -7,7 +7,8 @@ See Git checking messages for full history.
 - Windows: refactored how internal handles are stored (fixes #198)
 - Windows: removed side effects when leaving the context manager, resources are all freed
 - CI: run tests via xvfb-run on GitHub Actions (#248)
-- tests: Use `PyVirtualDisplay` instead of `xvfbwrapper` (#249)
+- tests: enhance ``test_get_pixels.py``, and try to fix a random failure at the same time (related to #251)
+- tests: use `PyVirtualDisplay` instead of `xvfbwrapper` (#249)
 - :heart: contributors: @mgorny, @CTPaHHuK-HEbA
 
 ## 8.0.3 (2023/04/15)

src/tests/conftest.py

@@ -4,6 +4,7 @@
 """
 import glob
 import os
+import platform
 from hashlib import md5
 from pathlib import Path
 from zipfile import ZipFile
@@ -55,6 +56,10 @@ def raw() -> bytes:
 @pytest.fixture(scope="session")
 def pixel_ratio() -> int:
     """Get the pixel, used to adapt test checks."""
+
+    if platform.system().lower() != "darwin":
+        return 1
+
     # Grab a 1x1 screenshot
     region = {"top": 0, "left": 0, "width": 1, "height": 1}
 

src/tests/test_bgra_to_rgb.py

@@ -14,7 +14,7 @@ def test_bad_length():
         image.rgb
 
 
-def test_good_types(raw):
+def test_good_types(raw: bytes):
     image = ScreenShot.from_size(bytearray(raw), 1024, 768)
     assert isinstance(image.raw, bytearray)
     assert isinstance(image.rgb, bytes)

src/tests/test_get_pixels.py

@@ -2,6 +2,8 @@
 This is part of the MSS Python's module.
 Source: https://github.com/BoboTiG/python-mss
 """
+
+import itertools
 import os
 
 import pytest
@@ -21,35 +23,27 @@ def test_grab_monitor():
 
 
 def test_grab_part_of_screen(pixel_ratio):
-    monitor = {"top": 160, "left": 160, "width": 160, "height": 160}
-    with mss(display=os.getenv("DISPLAY")) as sct:
-        image = sct.grab(monitor)
-    assert isinstance(image, ScreenShot)
-    assert isinstance(image.raw, bytearray)
-    assert isinstance(image.rgb, bytes)
-    assert image.top == 160
-    assert image.left == 160
-    assert image.width == 160 * pixel_ratio
-    assert image.height == 160 * pixel_ratio
-
-
-def test_grab_part_of_screen_rounded(pixel_ratio):
-    monitor = {"top": 160, "left": 160, "width": 161, "height": 159}
     with mss(display=os.getenv("DISPLAY")) as sct:
-        image = sct.grab(monitor)
-    assert isinstance(image, ScreenShot)
-    assert isinstance(image.raw, bytearray)
-    assert isinstance(image.rgb, bytes)
-    assert image.top == 160
-    assert image.left == 160
-    assert image.width == 161 * pixel_ratio
-    assert image.height == 159 * pixel_ratio
-
-
-def test_grab_individual_pixels():
-    monitor = {"top": 160, "left": 160, "width": 222, "height": 42}
-    with mss(display=os.getenv("DISPLAY")) as sct:
-        image = sct.grab(monitor)
-    assert isinstance(image.pixel(0, 0), tuple)
+        for width, height in itertools.product(range(1, 42), range(1, 42)):
+            monitor = {"top": 160, "left": 160, "width": width, "height": height}
+            image = sct.grab(monitor)
+
+            assert image.top == 160
+            assert image.left == 160
+            assert image.width == width * pixel_ratio
+            assert image.height == height * pixel_ratio
+
+
+def test_get_pixel(raw: bytes):
+    image = ScreenShot.from_size(bytearray(raw), 1024, 768)
+    assert image.width == 1024
+    assert image.height == 768
+    assert len(image.pixels) == 768
+    assert len(image.pixels[0]) == 1024
+
+    assert image.pixel(0, 0) == (135, 152, 192)
+    assert image.pixel(image.width // 2, image.height // 2) == (0, 0, 0)
+    assert image.pixel(image.width - 1, image.height - 1) == (135, 152, 192)
+
     with pytest.raises(ScreenShotError):
         image.pixel(image.width + 1, 12)