TST: Add test case to verify reloading the main window re-compiles th…

…e underlying ui files

pydm/tests/test_main_window.py

@@ -0,0 +1,24 @@
+import os
+
+from pydm import Display, PyDMApplication
+from qtpy import uic
+from unittest.mock import MagicMock, patch
+
+# The path to the .ui file for creating a main window
+test_ui_path = os.path.join(os.path.dirname(os.path.realpath(__file__)), "test_data", "test.ui")
+
+
+@patch("qtpy.uic.compileUi", wraps=uic.compileUi)
+def test_reload_display(wrapped_compile_ui: MagicMock, qapp: PyDMApplication) -> None:
+    """Verify that when a user reloads a PyDM window the underling display's ui file is actually reloaded"""
+    display = Display(parent=None, ui_filename=test_ui_path)
+
+    qapp.make_main_window()
+    qapp.main_window.set_display_widget(display)
+
+    # When the display is first created and loaded the underlying ui file gets compiled
+    wrapped_compile_ui.assert_called_once()
+
+    # Reloading should force a re-compile of the ui file to ensure any changes are picked up
+    qapp.main_window.reload_display(True)
+    assert wrapped_compile_ui.call_count == 2