Refactor initial document handling to separate command line from defa…

…ult document handling.

core/src/toga/app.py

@@ -608,35 +608,34 @@ def _create_standard_commands(self):
 
     def _create_initial_windows(self):
         """Internal utility method for creating initial windows based on command line
-        arguments. This method is used when the platform doesn't provide its own
-        command-line handling interface.
+        arguments.
 
-        If document types are defined, try to open every argument on the command line as
-        a document (unless the backend manages the command line arguments).
-        """
-
-        if not (self._impl.HANDLES_COMMAND_LINE and self._impl.CLOSE_ON_LAST_WINDOW):
-            doc_count = len(self.windows)
+        If document types are defined, and the backend doesn't have native command line
+        handling, try to open every argument on the command line as a document (unless
+        the backend manages the command line arguments).
 
-            # Process command line arguments if the backend doesn't handle them
-            if not self._impl.HANDLES_COMMAND_LINE and self.documents.types:
+        If, after processing all command line arguments, the app doesn't have at least
+        one window, the app's default initial document handling will be triggered.
+        """
+        # Process command line arguments if the backend doesn't handle them
+        if not self._impl.HANDLES_COMMAND_LINE:
+            if self.documents.types:
                 for filename in sys.argv[1:]:
-                    if self._open_initial_document(filename):
-                        doc_count += 1
-
-            # Ensure there is at least one document or window
-            if self.main_window is None and doc_count == 0:
-                if self.documents.types:
-                    if self._impl.CLOSE_ON_LAST_WINDOW:
-                        # Pass in the first document type as the default
-                        self.documents.new(self.documents.types[0])
-                    else:
-                        self.loop.run_until_complete(self.documents.request_open())
+                    self._open_initial_document(filename)
+
+        # Ensure there is at least one window
+        if self.main_window is None and len(self.windows) == 0:
+            if self.documents.types:
+                if self._impl.CLOSE_ON_LAST_WINDOW:
+                    # Pass in the first document type as the default
+                    self.documents.new(self.documents.types[0])
                 else:
-                    # No document types defined.
-                    raise RuntimeError(
-                        "App didn't create any windows, or register any document types."
-                    )
+                    self.loop.run_until_complete(self.documents.request_open())
+            else:
+                # No document types defined.
+                raise RuntimeError(
+                    "App didn't create any windows, or register any document types."
+                )
 
     def _startup(self) -> None:
         # Wrap the platform's event loop's task factory for task tracking

core/tests/app/test_document_app.py

@@ -1,9 +1,10 @@
 import sys
-from unittest.mock import AsyncMock, MagicMock, Mock
+from unittest.mock import AsyncMock, Mock
 
 import pytest
 
 import toga
+from toga.documents import DocumentSet
 from toga_dummy.app import App as DummyApp
 from toga_dummy.command import Command as DummyCommand
 from toga_dummy.utils import (
@@ -170,9 +171,9 @@ def test_create_no_cmdline_default_handling_close_on_last_window(monkeypatch):
 
     assert app.documents.types == [ExampleDocument]
 
-    # No documents or windows exist
-    assert len(app.documents) == 0
-    assert len(app.windows) == 0
+    # A default document has been created
+    assert len(app.documents) == 1
+    assert len(app.windows) == 1
 
 
 def test_create_no_cmdline_default_handling_no_close_on_last_window(monkeypatch):
@@ -190,18 +191,26 @@ def test_create_no_cmdline_default_handling_no_close_on_last_window(monkeypatch)
     # Mock request_open() because OpenFileDialog's response can't be set before the
     # app creation. Since request_open() is called during app initialization, we can't
     # set the dialog response in time, leading to an unexpected dialog response error.
-    monkeypatch.setattr(ExampleDocumentApp, "documents", MagicMock())
     mock_request_open = AsyncMock()
-    monkeypatch.setattr(ExampleDocumentApp.documents, "request_open", mock_request_open)
+    monkeypatch.setattr(DocumentSet, "request_open", mock_request_open)
 
     # Create the app instance
-    _ = ExampleDocumentApp(
+    app = ExampleDocumentApp(
         "Test App",
         "org.beeware.document-app",
         document_types=[ExampleDocument],
     )
 
-    # Check that request_open was called
+    assert app._impl.interface == app
+    assert_action_performed(app, "create App")
+
+    assert app.documents.types == [ExampleDocument]
+
+    # No documents have been created
+    assert len(app.documents) == 0
+    assert len(app.windows) == 0
+
+    # ...but request_open was called
     mock_request_open.assert_called_once()