Fix food spawn test and optimize test execution

pytest.ini

@@ -3,4 +3,8 @@ testpaths = tests
 python_files = test_*.py
 python_classes = Test*
 python_functions = test_*
-addopts = -v --tb=short 
+addopts = -v --tb=short -n auto
+markers =
+    slow: marks tests as slow (deselect with '-m "not slow"')
+    integration: marks tests as integration tests
+    unit: marks tests as unit tests 

requirements.txt

@@ -2,3 +2,4 @@ pygame==2.5.2
 numpy==1.24.3
 black==23.12.1  # for code formatting
 pytest==7.4.3  # for testing
+pytest-xdist==3.5.0  # for parallel test execution 

src/food.py

@@ -17,22 +17,20 @@ class Food:
             height: Game area height
             occupied_positions: List of positions (typically snake body positions) where food shouldn't spawn
         """
-        # Calculate valid grid positions
-        valid_x = range(0, width, self.block_size)
-        valid_y = range(0, height, self.block_size)
-        
-        # Create list of all possible positions
-        all_positions = [
-            (x, y) for x in valid_x for y in valid_y
+        # Calculate all valid grid positions
+        valid_positions = [
+            (x, y)
+            for x in range(0, width, self.block_size)
+            for y in range(0, height, self.block_size)
             if (x, y) not in occupied_positions
         ]
         
-        if not all_positions:
+        if not valid_positions:
             # No valid positions (snake fills screen) - game should be won
             return
         
-        # Choose random position
-        self.position = random.choice(all_positions)
+        # Choose random position from valid positions
+        self.position = random.choice(valid_positions)
 
     def draw(self, screen: pygame.Surface) -> None:
         """Draw the food on the screen"""

tests/conftest.py

@@ -6,11 +6,12 @@ import os
 # Add src directory to Python path
 sys.path.insert(0, os.path.abspath(os.path.join(os.path.dirname(__file__), '..')))
 
-@pytest.fixture(autouse=True)
-def pygame_init():
-    """Initialize pygame for all tests"""
+def pytest_configure(config):
+    """Initialize pygame once before any tests run"""
     pygame.init()
-    yield
+
+def pytest_unconfigure(config):
+    """Clean up pygame after all tests are done"""
     pygame.quit()
 
 @pytest.fixture