Hey @RobAtOpinyin,
Ideally when you delete the coverage folder and .report.json the fresh coverage report would be generated as and when you test each function/line/block of code on your App.js.
Can you share your FDK version? Was there code changes while testing the app?
@zach_jones_noel I have managed to clear the coverage and start again but as I test the app.js code, the update of the report is really inconsistent. There are functions and branches that are clearly working in the tests but the report is not updating to reflect it. This is not an issue in the code that operates in the full page app. That updates the report as soon as its tested.