feat: Improve macOS app chooser functionality and enhance drag operation success criteria

tests/unit/test_main_window.py

@@ -206,11 +206,31 @@ class TestMainWindowOpenWith:
         test_file = sample_config.allowed_roots[0] / "open_with_macos.txt"
         test_file.write_text("test")
 
-        class _Result:
+        call_count = [0]  # Use list to make it mutable in nested function
+        
+        class _AppChooseResult:
             returncode = 0
-
+            stdout = "TextEdit"  # Simulated chosen app name
+        
+        class _OpenResult:
+            returncode = 0
+            stdout = ""
+        
+        def mock_run(*args, **kwargs):
+            """Mock subprocess.run with two different behaviors per call."""
+            call_count[0] += 1
+            # First call: osascript to choose application
+            if call_count[0] == 1:
+                return _AppChooseResult()
+            # Second call: open command to open the file
+            elif call_count[0] == 2:
+                return _OpenResult()
+            else:
+                raise AssertionError(f"Unexpected call #{call_count[0]} to subprocess.run")
+        
+        
         with patch("webdrop_bridge.ui.main_window.sys.platform", "darwin"):
-            with patch("webdrop_bridge.ui.main_window.subprocess.run", return_value=_Result()):
+            with patch("webdrop_bridge.ui.main_window.subprocess.run", side_effect=mock_run):
                 assert window._open_with_app_chooser(str(test_file)) is True
 
     def test_open_with_app_chooser_unsupported_platform(self, qtbot, sample_config):