getPathForShellItem throws on error

Author: adpinola

packages/file_selector/file_selector_windows/lib/src/file_selector_dart/dialog_wrapper.dart

@@ -181,34 +181,40 @@ class DialogWrapper {
       Pointer<Pointer<COMObject>> shellItemArrayPtr,
       Pointer<Uint32> shellItemCountPtr,
       Pointer<Pointer<COMObject>> shellItemPtr) {
-    final List<String> files = <String>[];
-    if (_isOpenDialog) {
-      _lastResult = _dialogController.getResults(shellItemArrayPtr);
-      if (!SUCCEEDED(_lastResult)) {
-        return null;
-      }
+    try {
+      final List<String> files = <String>[];
+      int lastOperationResult;
+      if (_isOpenDialog) {
+        lastOperationResult = _dialogController.getResults(shellItemArrayPtr);
+        if (!SUCCEEDED(lastOperationResult)) {
+          throw WindowsException(lastOperationResult);
+        }
 
-      final IShellItemArray shellItemResources =
-          IShellItemArray(shellItemArrayPtr.cast());
-      _lastResult = shellItemResources.getCount(shellItemCountPtr);
-      if (!SUCCEEDED(_lastResult)) {
-        return null;
-      }
-      for (int index = 0; index < shellItemCountPtr.value; index += 1) {
-        shellItemResources.getItemAt(index, shellItemPtr);
+        final IShellItemArray shellItemResources =
+            IShellItemArray(shellItemArrayPtr.cast());
+        lastOperationResult = shellItemResources.getCount(shellItemCountPtr);
+        if (!SUCCEEDED(lastOperationResult)) {
+          throw WindowsException(lastOperationResult);
+        }
+        for (int index = 0; index < shellItemCountPtr.value; index += 1) {
+          shellItemResources.getItemAt(index, shellItemPtr);
+          final IShellItem shellItem = IShellItem(shellItemPtr.cast());
+          files.add(_shellWin32Api.getPathForShellItem(shellItem));
+          _shellWin32Api.releaseShellItem(shellItem);
+        }
+      } else {
+        lastOperationResult = _dialogController.getResult(shellItemPtr);
+        if (!SUCCEEDED(lastOperationResult)) {
+          throw WindowsException(lastOperationResult);
+        }
         final IShellItem shellItem = IShellItem(shellItemPtr.cast());
         files.add(_shellWin32Api.getPathForShellItem(shellItem));
         _shellWin32Api.releaseShellItem(shellItem);
       }
-    } else {
-      _lastResult = _dialogController.getResult(shellItemPtr);
-      if (!SUCCEEDED(_lastResult)) {
-        return null;
-      }
-      final IShellItem shellItem = IShellItem(shellItemPtr.cast());
-      files.add(_shellWin32Api.getPathForShellItem(shellItem));
-      _shellWin32Api.releaseShellItem(shellItem);
+      return files;
+    } on WindowsException catch (ex) {
+      _lastResult = ex.hr;
+      return null;
     }
-    return files;
   }
 }

packages/file_selector/file_selector_windows/lib/src/file_selector_dart/shell_win32_api.dart

@@ -32,7 +32,7 @@ class ShellWin32Api {
       );
 
       if (!SUCCEEDED(operationResult)) {
-        return '';
+        throw WindowsException(operationResult);
       }
       return ptrPath.value.toDartString();
     });

packages/file_selector/file_selector_windows/test/file_selector_dart/dialog_wrapper_test.dart

@@ -272,7 +272,24 @@ void main() {
     verify(mockFileDialogController.getResult(any)).called(1);
   });
 
-  test('[DialogMode == Save] show should the selected directory for', () {
+  test(
+      '[DialogMode == Save] show should return null if cannot getPathForShellItem',
+      () {
+    final DialogWrapper dialogWrapperModeSave =
+        DialogWrapper.withFakeDependencies(
+            mockFileDialogController, DialogMode.save, mockShellWin32Api);
+    const int parentWindow = 0;
+    when(mockFileDialogController.show(parentWindow)).thenReturn(S_OK);
+    when(mockFileDialogController.getResult(any)).thenReturn(S_OK);
+    when(mockShellWin32Api.getPathForShellItem(any))
+        .thenThrow(WindowsException(E_FAIL));
+
+    final List<String?>? result = dialogWrapperModeSave.show(parentWindow);
+
+    expect(result, null);
+  });
+
+  test('[DialogMode == Save] show should return the file path', () {
     const String filePath = 'path/to/file.txt';
     final DialogWrapper dialogWrapperModeSave =
         DialogWrapper.withFakeDependencies(