Some code flow improvements and main GUI test coverage

tests/conftest.py

@@ -54,8 +54,10 @@ def resetConfigVars():
     CONFIG.setBackupPath(_TMP_ROOT)
     CONFIG.setGuiFont(None)
     CONFIG.setTextFont(None)
+    CONFIG.backupOnClose = False
     CONFIG._homePath = _TMP_ROOT
     CONFIG._dLocale = QLocale("en_GB")
+    CONFIG.pdfDocs = _TMP_ROOT / "manual.pdf"
     CONFIG.guiLocale = "en_GB"
     return
 
@@ -72,6 +74,7 @@ def sessionFixture():
         shutil.rmtree(_TMP_ROOT)
     _TMP_ROOT.mkdir()
     _TMP_CONF.mkdir()
+    (_TMP_ROOT / "manual.pdf").touch()
     return
 
 
@@ -161,6 +164,7 @@ def nwGUI(qtbot, monkeypatch, functionFixture):
     monkeypatch.setattr(QMessageBox, "result", lambda *a: QMessageBox.StandardButton.Yes)
 
     nwGUI = main(["--testmode", f"--config={_TMP_CONF}", f"--data={_TMP_CONF}"])
+    assert nwGUI is not None
     qtbot.addWidget(nwGUI)
     resetConfigVars()
     nwGUI.docEditor.initEditor()