Originally published on https://blog.mistadikay.com/when-polymorphism-bites-you-in-the-ass/

A curious problem I faced recently when Java polymorphism met Scala polymorphism and they gave a birth to an ugly baby that I had to confront.

A short prehistory: we have a huge monolithic Scala web-application that was written 4 years ago and was barely maintained since then (however, it worked surprisingly well all that time). There are a lot of Java dependencies used in the project and despite the claims that Scala has “seamless Java interop”, it’s not all rainbows and unicorns.

“Error: ambiguous reference to overloaded definition…” WHAT?

We use an excellent Mockito framework in unit-tests, but it was never upgraded…

It’s been about a year since me and Kir Belevich started using React at Lazada Group for some internal admin interfaces. We learned a lot during that time and our minds have been heavily shifted by that one-way data-flow philosophy React pushes.

Since React is not exactly a framework, but just a view library, we have both freedom of choice and a burden of responsibility, like: how to structure your application, how to manage its state or how to style your components. And styling was one of the first problems we were trying to address.

Problems with styling

There are many issues with…

Reactive future

What we love about React is how simple and enjoyable its declarative way of constructing components. And when GraphQL was introduced our minds were blown because we realized: we can do the same with data, describing what our components need and not caring about how and when it will be delivered.

Also, Netflix introduced JSONGraph and Falcor this May. What’s interesting here is that working completely independent from Facebook they came up with very similar ideas. So, basically we can see a solid trend here.

REST present

There is one frustrating thing about GraphQL/Falcor though: both of them require certain backend implementation…

Denis Koltsov

Web Developer | javascript (react, node), go, scala, interested in elixir, clojure, haskell

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