Testing runs through nightwatch that treats an electron application as a special version of chrome, which it is. It basically calls the executable which is built by the ./rundist.bash script which creates executables based on the current channel configuration package.json, ie "version": "1.0.8-insiders"
Executables are stored in the ./release directory. Without that executable you cannot run tests. You cannot call tests on local development instance that is launched by yarn start:dev. You need to create an exec first.
Executables are stored in the ./release directory. Without that executable you cannot run tests. You cannot call tests on local development instance that is launched by yarn start:dev. You need to create an executable file first.