Imperative shell, functional core

Imperative shell, functional core is one of the concepts that influenced my programming career the most. It perfectly formulates how to write clean, easily testable code and always keeps you wondering whether you did enough to extract the functional pieces. During my preparations for the Mobile Warsaw #62 talk I…

Practical functional programming in Swift

Recently, I came across a couple of real-world examples that illustrate functional programming usage in Swift. All those examples have a single thing in common - they have been initially written in an imperative manner, which made them harder to read and extend. The article provides an in-depth description of…

Continuous delivery with Travis and fastlane

Continuous delivery is a key to a healthy communication with your customer. However, it is not a common practice for iOS developers to set up a continuous delivery pipeline. It is likely caused by the inferior tooling provided by the Apple itself. This tutorial aims to present a painless way…

UI testing iOS apps for humans

No one likes to be blamed for the mistakes. This is especially true for software engineers. Over the years they came up with countless ideas which make software development less fragile and error-prone. It is safe to say that ever growing number of precaution steps taken to maximize the quality…

UIView providers for Swift unit testing

As you might already know, I deliberately chose not to use storyboards for my Swift code. Instead, I build all of the views programmatically and inject them through initializers into suitable controllers. Although this approach works really nice, it has drawbacks when it comes to unit testing. Imagine having a…

Functional reactive programming in Python

Functional reactive programming (FRP) is probably the hottest 🔥 topic in mobile apps development world right now. GitHub trending repositories list is packed with reactive frameworks (RxSwift, ReactiveCocoa and RxJava to name just a few). But is the pattern's usability limited to iOS and Android only? For the past couple of…

Adding iMessage integration to your app

So you already have an app and you are trying to engage users even more... What is a better way to do that than using one of the coolest iOS 10 features - iMessage integration? This Tuesday Apple rolled out iOS 10 together with Messages framework. It provides building blocks…