Fix Windows CI test failures

- Fix file handle leaks by using context managers for PIL Image.open()
- Properly close image files to prevent PermissionError during temp cleanup
- Fix permission denied test for Windows platform compatibility
- Use platform-specific file permission handling in tests

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

Author: kocabiyik

src/withoutbg/api.py

@@ -49,7 +49,8 @@ def _encode_image(self, image: Union[str, Path, Image.Image, bytes]) -> str:
     def _decode_image(self, base64_string: str) -> Image.Image:
         """Decode base64 string to PIL Image."""
         image_bytes = base64.b64decode(base64_string)
-        return Image.open(io.BytesIO(image_bytes))
+        with Image.open(io.BytesIO(image_bytes)) as img:
+            return img.copy()
 
     def _resize_for_api(
         self, image: Image.Image, max_size: int = 1024
@@ -134,11 +135,13 @@ def remove_background(
         try:
             # Store original image for local alpha application
             if isinstance(input_image, (str, Path)):
-                original_image = Image.open(input_image)
+                with Image.open(input_image) as img:
+                    original_image = img.copy()
             elif isinstance(input_image, Image.Image):
                 original_image = input_image.copy()
             elif isinstance(input_image, bytes):
-                original_image = Image.open(io.BytesIO(input_image))
+                with Image.open(io.BytesIO(input_image)) as img:
+                    original_image = img.copy()
             else:
                 raise APIError(f"Unsupported image type: {type(input_image)}")
 

src/withoutbg/models.py

@@ -435,9 +435,11 @@ def remove_background(
         """
         # Load image
         if isinstance(input_image, (str, Path)):
-            image = Image.open(input_image)
+            with Image.open(input_image) as img:
+                image = img.copy()
         elif isinstance(input_image, bytes):
-            image = Image.open(io.BytesIO(input_image))
+            with Image.open(io.BytesIO(input_image)) as img:
+                image = img.copy()
         elif isinstance(input_image, Image.Image):
             image = input_image.copy()
         else:

tests/test_cli_e2e.py

@@ -420,24 +420,46 @@ def test_e2e_permission_denied_output(self, real_test_image_path, temp_dir):
         if not real_test_image_path.exists():
             pytest.skip("Real test image not available")
 
-        # Create a read-only directory
+        import platform
+        import stat
+
+        # Create a read-only directory - Windows requires different approach
         readonly_dir = temp_dir / "readonly"
         readonly_dir.mkdir()
-        readonly_dir.chmod(0o444)  # Read-only
-
-        try:
+        
+        # Use platform-specific permission handling
+        if platform.system() == "Windows":
+            # On Windows, create a file first, then make it read-only
             output_path = readonly_dir / "output.png"
-
+            output_path.touch()
+            output_path.chmod(stat.S_IREAD)
+            
             result = self.runner.invoke(
                 main, [str(real_test_image_path), "--output", str(output_path)]
             )
-
+            
             # Should fail due to permission error
             assert result.exit_code == 1
-
-        finally:
+            
             # Restore permissions for cleanup
-            readonly_dir.chmod(0o755)
+            output_path.chmod(stat.S_IWRITE | stat.S_IREAD)
+        else:
+            # Unix-style read-only directory
+            readonly_dir.chmod(0o444)
+            
+            try:
+                output_path = readonly_dir / "output.png"
+
+                result = self.runner.invoke(
+                    main, [str(real_test_image_path), "--output", str(output_path)]
+                )
+
+                # Should fail due to permission error
+                assert result.exit_code == 1
+
+            finally:
+                # Restore permissions for cleanup
+                readonly_dir.chmod(0o755)
 
     @pytest.mark.real_processing
     def test_e2e_disk_space_simulation(self, real_test_image_path, temp_dir):