Added tests for core

core/src/toga/platform.py

@@ -8,7 +8,7 @@ if sys.version_info >= (3, 10):
 else:
     # Before Python 3.10, entry_points did not support the group argument;
     # so, the backport package must be used on older versions.
-    from importlib_metadata import entry_points
+    from importlib_metadata import entry_points  # pragma: no cover
 
 
 # Map python sys.platform with toga platforms names

core/tests/app/test_app.py

@@ -8,6 +8,8 @@ from unittest.mock import Mock
 import pytest
 
 import toga
+from toga.screen import Screen as ScreenInterface
+from toga_dummy.screen import Screen as ScreenImpl
 from toga_dummy.utils import (
     assert_action_not_performed,
     assert_action_performed,
@@ -621,3 +623,10 @@ def test_deprecated_name():
     assert app.formal_name == "Test App"
     with pytest.warns(DeprecationWarning, match=name_warning):
         assert app.name == "Test App"
+
+
+def test_screens(app):
+    assert isinstance(app.screens, list)
+    for screen in app.screens:
+        assert isinstance(screen, ScreenInterface)
+        assert isinstance(screen._impl, ScreenImpl)

core/tests/test_screen.py

@@ -0,0 +1,25 @@
+from toga_dummy.utils import assert_action_performed
+
+
+def test_name(app):
+    assert app.screens[0].name == "primary_screen"
+    assert app.screens[1].name == "secondary_screen"
+
+
+def test_origin(app):
+    assert app.screens[0].origin == (0, 0)
+    assert app.screens[1].origin == (-1920, 0)
+
+
+def test_size(app):
+    assert app.screens[0].size == (1920, 1080)
+    assert app.screens[1].size == (1920, 1080)
+
+
+# Same as for the window as_image() test.
+def test_as_image(app):
+    """A screen can be captured as an image"""
+    image = app.screens[0].as_image()
+    assert_action_performed(app.screens[0], "get image data")
+    # Don't need to check the raw data; just check it's the right size.
+    assert image.size == (318, 346)

core/tests/test_window.py

@@ -4,6 +4,8 @@ from unittest.mock import Mock
 import pytest
 
 import toga
+from toga.screen import Screen as ScreenInterface
+from toga_dummy.screen import Screen as ScreenImpl
 from toga_dummy.utils import (
     assert_action_not_performed,
     assert_action_performed,
@@ -354,6 +356,22 @@ def test_as_image(window):
     assert image.size == (318, 346)
 
 
+def test_screen(window, app):
+    assert isinstance(window.screen, ScreenInterface)
+    assert isinstance(window.screen._impl, ScreenImpl)
+    # Cannot actually change window.screen, so just check
+    # the window positions as a substitute for moving the
+    # window between the screens.
+    assert window.position == (100, 100)
+    window.screen = app.screens[1]
+    assert window.position == (-1820, 100)
+
+
+def test_screen_position(window, app):
+    window.screen_position = (0, 0)
+    assert window.screen_position == (0, 0)
+
+
 def test_info_dialog(window, app):
     """An info dialog can be shown"""
     on_result_handler = Mock()

dummy/src/toga_dummy/screen.py

@@ -1,3 +1,6 @@
+from pathlib import Path
+
+import toga_dummy
 from toga.screen import Screen as ScreenInterface
 
 from .utils import LoggedObject  # noqa
@@ -28,5 +31,8 @@ class Screen(LoggedObject):
     def get_size(self):
         return (1920, 1080)
 
+    # Same as for the window as_image().
     def get_image_data(self):
-        self._action("get_image_data")
+        self._action("get image data")
+        path = Path(toga_dummy.__file__).parent / "resources/screenshot.png"
+        return path.read_bytes()