iOS Code Review - newsletter for iOS developers

Issue #89 of iOS Code Review is out 📬 This week: 🧚 SwiftFairy, a Mac app that gives your coding agent a real SwiftUI review. The checks are rule-based, so it gives the same findings on the same code every time. 🗣️ How to tell Siri AI what's on your app's screen, with code for single items and lists 🛡️ Swift 6.4's withTaskCancellationShield, so cleanup finishes after a cancel. It only works on iOS 27, so you need an availability check if you support 26. ✅ SE-0546 was accepted: public memberwise inits in extensions will compile 📱 New answers from Apple's iPhone Duo Group Labs, including that you can't opt out of resizing Thanks to Runway for sponsoring again. Triage by Runway puts QA regressions, beta feedback, App Store reviews and crashes in one inbox. Link to the full edition in the comments 👇

Issue #88 of iOS Code Review is out 📬 Two betas shipped this week, and one of them will change your pull requests. Xcode 27.2 beta adds a JSON project format, project.xcproj, that you can use instead of project.pbxproj. Each file lists its own target membership, and the layout matches the Project navigator. Adding a file used to touch three separate parts of the pbxproj. Now it's one line. Before you switch, make sure everyone on your team is on Xcode 27, because Xcode 26 can't open the new format. Also in this issue: 📱 The iPhone Duo simulator is finally out in Xcode 27.1 beta, with a small CLI that folds it from your scripts ↕️ Duo toolbars can move into a vertical bar, and there's a clean way to backport those APIs without raising your deployment target 🐢 A launch argument that tells you which ForEach is slowing down your List 💥 iOS 27's new extension that handles crash reports in a separate process after your app dies 💳 Subscription bundles, suites, and multiseat buying. Multiseat is already on by default in App Store Connect, so decide before October 22 Thanks to Runway for sponsoring this week. Triage by Runway pulls every incoming app issue into one inbox: QA regressions, beta feedback, App Store reviews and crashes. It removes duplicates, assigns them and tracks the fixes. Read it here 👇 #iOSDev #Swift #SwiftUI #Xcode

iOS 27 and Xcode 27 shipped on Monday. If you maintain an iOS app, a few things now have deadlines. Starting April 2027, App Store Connect only accepts iOS apps built with the iOS 27 SDK. That includes adopting Liquid Glass, so the time to plan for it is now, not in March. Xcode 27 also changes what coding agents can do. They can now boot simulators, launch your app, tap through the UI, take screenshots to check their own work, and read your debugger console. Plans show up as editable Markdown that you approve before any code gets written. There is also a new setting that limits which files an agent can touch. It's off by default and worth turning on. Issue #87 of iOS Code Review also covers: → A Swift 6.4 source break with a one-line fix → Rerunning a flaky test until it fails with swift test --repeat-until fail → LLDB's new task tree command for debugging Swift concurrency → Debounced SwiftUI search that never shows stale results → ArrangementView and the fold and hinge APIs coming for iPhone Duo #iOSDev #Swift #SwiftUI #Xcode

Apple announced iPhone Duo today. Ships October 23. Here's what your app does on it right now: Built before iOS 27: centered on the inner display with dead space around it. Built on iOS 27: extends past the status bar. Built on iOS 27.1: edge to edge, nav buttons stacked vertically. Six weeks to get from the first line to the third. I wrote a special edition of iOS Code Reviews on exactly that: the size-class map for both displays, why UIRequiresFullScreen won't save you, asymmetric safe areas, the new ReservedRegion API, and the App Resizability skill in Xcode 27.1. Code included. Also announcing: we're going weekly, and each edition now has three placements for your own iOS and Mac app or tools. Reply to the email to grab one! #iOSDev #Swift #SwiftUI #iPhoneDuo

Apple just gave every iOS coding agent seven of its own best-practice guides, built directly into Xcode 27. One command exports them: SwiftUI patterns, UIKit modernization, a security audit checklist. All written by Apple's own team, all readable by Claude, Cursor, or whatever your agent stack looks like. Pair that with Xcode's new headless MCP server (build, run, and test on Simulator without opening the IDE) and a quieter shift is underway: the workflow where you never touch Xcode's UI to ship an app is no longer hypothetical. This week's issue also covers the foldable-device clues buried in iOS 27's beta code and the SwiftUI layout patterns worth learning now, before either of these becomes the default. Full issue is linked below.

iOS 27 is already hinting at foldable support ! "foldState," "angleDegrees," dual-battery strings, and a push for resizable, adaptive layouts across every app. If you're still hardcoding size classes, now's the time to stop!

iOS 27 beta 6 dropped Monday. Xcode 27 beta 5 the week before. Here are the three changes worth acting on before the September scramble! https://lnkd.in/gFAGBa4w

New issue of iOS Code Reviews is out! Three shifts worth acting on now, while iOS 27 is still in beta (stable in September): Liquid Glass is mandatory. Xcode 27 drops the UIDesignRequiresCompatibility flag, so the iOS 26 opt-out is gone. And it is not just paint: the floating tab bar and transparent nav bars change your layout geometry. Foundation Models opens up. The on-device-only framework now takes any backend behind the same LanguageModelSession API, so you can swap to Private Cloud Compute or an MLX model in about one line. Non-modal panels in SwiftUI, the native way, with presentationBackgroundInteraction and detents. Read it here: https://lnkd.in/g2CWE38D #iOSDev #SwiftUI #Swift

iOS Code Reviews #81 is out SwiftUI's toolbars finally get real overflow logic, iPhone apps go resizable in iOS 27 (yes, layout bugs incoming), and a solid community Agent Skill for Swift Testing. https://lnkd.in/dVssPKdf

All the latest from WWDC in Issue #80! https://lnkd.in/dem8ykAW