Roman Mishchenko Software Engineer (Cocoa)

WWDC24 Highlights: A Closer Look For Developers

#Xcode
#Swift

04 July 2024 • 3 min read

Here's what they didn't tell you at WWDC: Xcode's Copilot, Swift Testing, and the latest SwiftUI Previews. I'm Roman Mishchenko, an engineer at CleanMyMac, and let’s dive into the most important updates for iOS and macOS developers.

Apple's annual WWDC unveiled updates across all operating systems from iOS to VisionOS. We won’t rehash all the details, but here are a few key points that Apple didn't spotlight in the main presentation.

Xcode Developments

Copilot

Apple has launched Xcode 16 beta, featuring a code prediction model specifically designed for coding in Swift and Objective-C. This model, already tested by MacPaw engineers, operates offline directly on your device, though it is currently a bit slower than Copilot.

Note: the code prediction model is only compatible with Xcode 16 on macOS Sequoia. Additionally, the much-anticipated Assistant Editor for Xcode was not included in the first beta; we are awaiting new releases.

Workflow

SwiftUI Preview now uses shared products from Build and Run. That means Preview will no longer rebuild the project if it has already been built for running, which significantly simplifies UI testing.

Apple also redesigned the Instruments interface, adding powerful tools for detecting memory leaks.

For macOS Sequoia and iOS 18, Dwarf-5 symbols will be used by default for debugging.

Localizable

Localization improvements include a new 'Do Not Translate' tag for strings, easier navigation, specific string searches, and automated error checking in string catalogs. In my opinion, the most significant improvements are the enhanced text interactions with user prompts and better number formatting.

Swift Developments

Swift now operates under its own GitHub organization, expanding its development beyond Apple’s ecosystem. Swift will now be available on Fedora and Debian distros, as well as embedded systems.

An unexpected announcement was the introduction of cross-chain compilation between Linux and macOS using Static Linux SDK. Now, you can swiftly deploy code from macOS to a Linux server.

Swift Testing

Apple has created a new open-source framework to simplify code testing with macros, named Swift Testing. It has two main APIs, #expect and #require. #expect uses Swift expressions and operators to record evaluated values, while #require ensures early termination of the test.

Additionally, new features now support organizing tests by tags, customizing names, configuring behaviors, and setting up test suites based on characteristics that define test conditions.

Overall, Swift Testing can quickly locate issues when tests fail and streamlines the testing process across various platforms including Apple, Linux and Windows.