A while ago I’ve published a post that explains how you can use AsyncStream to build your own asynchronous sequences in Swift Concurrency. Since writing that post, a new approach to creating AsyncStream objects has been introduced to allow for more convenience stream building. In this post, I’ll expand on what we’ve already covered in the previous post so that we don’t have to go over everything from scratch. By the end of this post you will understand the new and more convenient makeStream method that was added to AsyncStream. You’ll learn how and when it makes sense to build...

When you work with CI, you’ll know how frustrating it can be when a CI server has versions of Xcode or other tools installed than the tools that you’re using. Especially major Xcode releases can be problematic. If your CI doesn’t have the same new versions available while your project uses recently released features which will lead your builds to fail. An obvious example of this would be when you start using features that are exclusive to the latest iOS version. If Xcode doesn’t know about these features then your project won’t build. An out of date CI can cause...

The long awaited iOS 17.4 and iPadOS 17.4 have just been released which means that we could slowly but surely start seeing alternative app stores to appear if you’re an EU iOS user. Alongside the 17.4 releases Apple has made Xcode 15.3 and Swift 5.10 available. There’s not a huge number of proposals included in Swift 5.10 but that doesn’t make this release less significant. With Swift 5.10, Apple has managed to close some large gaps that existed in Swift Concurrency’s data safety features. In short, this means that the compiler will be able to catch more possible thread safety...

When you’re decoding JSON, you’ll run into situations where you’ll have to decode dates every once in a while. Most commonly you’ll probably be dealing with dates that conform to the ISO-8601 standard but there’s also a good chance that you’ll have to deal with different date formats. In this post, we’ll take a look at how you can leverage some of Swift’s built-in date formats for en- and decoding data as well as providing your own date format. We’ll look at some of the up- and downsides of how Swift decodes dates, and how we can possibly work around...

When Swift 2.0 added the throws keyword to the language, folks were somewhat divided on its usefulness. Some people preferred designing their APIs with an (at the time) unofficial implementation of the Result type because that worked with both regular and callback based functions. However, the language feature got adopted and a new complaint came up regularly. The way throws in Swift was designed didn’t allow developers to specify the types of errors that a function could throw. In every do {} catch {} block we write we have to assume and account for any object that conforms to the...

Swift’s current concurrency model leverages tasks to encapsulate the asynchronous work that you’d like to perform. I wrote about the different kinds of tasks we have in Swift in the past. You can take a look at that post here. In this post, I’d like to explore the rules that Swift applies when it determines where your tasks and functions run. More specifically, I’d like to explore how we can determine whether a task or function will run on the main actor or not. We’ll start this post by very briefly looking at tasks and how we can determine where...

With iOS 17, we’ve gained a new way to provide observable data to our SwiftUI views. Until iOS 17, we’d use either an ObservableObject with @StateObject, @ObservedObject, or @EnvironmentObject whenever we had a reference type that we wanted to observe in one of our SwiftUI views. For lots of apps this worked absolutely fine, but these objects have a dependency on the Combine framework (which in my opinion isn’t a big deal), and they made it really hard for developers to limit which properties a view would observe. In iOS 17, we gained the new @Observable macro. I wrote about...

As we work on projects, we usually add more code than we remove. At least that’s how things are at the beginning of our project. While our project grows, the needs of the codebase change, and we start refactoring things. One thing that’s often quite hard to get exactly right when coding is the kinds of abstractions and design patterns we actually need. In this post, I would like to explore a mechanism that I like to leverage to make sure my code is robust without actually worrying too much about abstractions and design patterns in the first place. We’ll...

Having a local git repository is a smart thing to do. It’s even smarter to push your local git repositories up to a remote server so that you can collaborate with others, clone your repository on a separate machine, or have a backup of your code in case you’re replacing your current development machine with another. A possibly less obvious benefit of hosting your git repository somewhere is that lots of git servers provide useful features like Pull Requests for code reviews, issue tracking, and more. In this post, you will learn how you can set up a new repository...

Git is great, and when it works well it can be a breeze to work with. You push , pull, commit, branch, merge, but then… you get into a merge conflict, In this post, we’ll explore merge conflicts. We’ll look at why they happen, and what we can do to avoid running into merge conflicts in the first place. Let’s start by understanding why a merge conflict happens. Understanding why a merge conflict happens Git is usually pretty good at merging together branches or commits. So why does it get confused sometimes? And what does it mean when a merge...