I am getting this while running app on simulator using xCode, version 9.2
I've tried other solution mentioned on Stack overflow & Github S1S2 S3 S4 but most of the solution are mentioned for android.
P.S. This project also includes purescript code explained here Integrate Pure Script in your React Native project
create index.js, index.android.js and index.ios.js whith the same content. I do have all of them and it solved my issue