Railway Oriented Programming in JavaScript by Dominik Saran

Ever wondered why error handling in JavaScript applications is so cumbersome and verbose? Could we do better? Could just we forget about all that try-catch stuff, ‘undefined’ is not an object and failed promises (pun intended), and at the same time have our app just work? Well, perhaps we could. Enter railway-oriented programming. It’s not a new paradigm or anything - it’s just a clever way to organize our code to be able to focus on the actual problem (the business logic), instead of endless error handling - and still have those errors handled nicely.
Agenda:
The Problem
The solution v.1.0 (without ROP)
The solution v.2.0 (with ROP)
Live example (PESEL number validation)
Questions

[@kshitijpatil2019]

Don't you think we may face event loop related issues if we use promise this way? Like promise callbacks are scheduled to micro queue, so we might run into some race conditions while we were actually expecting things to be executed sequentially

[@0xc0ffee_]

Could you explain why that is? If you await those promises your code becomes essentially synchronous

[@coder_one]

@@0xc0ffee_ javascript loops are synchronous. Using them with asynchronous code can lead to problems