Thanks for providing the migration tool, it did help in migrating some files. I have observed that once migrated errors still persists in the file i.e. a few migrated APIs are shown in error.
Prev version: ui.setFocus(widgetLocate)
New version: ui.ensureThat(widgetLocate.hasFocus())
Please note widgetLocate is of type IWidgetLocator for which hasFocus method is not defined. I had to manually update this code.
There are several other places where manual upgrade would be required.
Also, I have faced this issue as well: viewtopic.php?f=5&t=4862