Debugging an app based on Combine

It's a common idea that debugging reactive code is more difficult than debugging imperative code. Unfortunately, this is not completely wrong: in part, because of the nature of the code; in part, because the development tools are not sophisticated enough to follow this new paradigm.

Combine, however, implements a few convenient ways to help us better understand what happens in our streams.

In this recipe, we'll learn three techniques to debug a Combine stream.

I admit that all three are a bit basic; however, they are a starting point and should be enough to start to understand how to deal with errors in the streams.

Getting ready

Let's create a SwiftUI app called DebuggingCombineApp in Xcode.

How to do it…

Given the limited possibilities of debugging Combine, we are not implementing a sophisticated app, but a trivial three-button app that calls the three possible ways of debugging Combine:

• Handling...