If I use the method callAsyncJavaScript() my app will compile, but it won't run on older simulators.
Specifically, in a brand new Storyboard project, I added this to `viewDidLoad():
let webView = WKWebView() webView.callAsyncJavaScript("1", in: nil, in: .page) { result in print("\(result)") }
This runs fine with Xcode 16.3 targeting the iOS 18.4 simulator. It doesn't work if I target the iOS 18.3.1 simulator or the iOS 17.5 simulator. It does work on an iPhone 15 Pro running iOS 18.4 and it works on an iPhone 12 Pro running iOS 17.7.1.
It goes without saying that this used to work on Xcode 16.2 and earlier, since my real project has been using that API for 3 or 4 years now.
The specific error is
dyld[89984]: Symbol not found: _$sSo9WKWebViewC6WebKitE19callAsyncJavaScript_9arguments2inAF17completionHandlerySS_SDySSypGSo11WKFrameInfoCSgSo14WKContentWorldCys6ResultOyyps5Error_pGcSgtF Referenced from: <82CC68A8-9426-343E-82CD-5443F53A6919> /Users/dave/Library/Developer/CoreSimulator/Devices/69CE58A3-8162-4616-B110-5857E6E2889F/data/Containers/Bundle/Application/3F27AAA0-8E96-437D-A1F4-DECD2E1A95B5/CallAsyncJavascript.app/CallAsyncJavascript.debug.dylib Expected in: <E11EC0F5-2AD1-3402-AB03-31A85EA6EB3A> /Library/Developer/CoreSimulator/Volumes/iOS_21F79/Library/Developer/CoreSimulator/Profiles/Runtimes/iOS 17.5.simruntime/Contents/Resources/RuntimeRoot/System/Library/Frameworks/WebKit.framework/WebKit
Our engineering teams need to investigate this issue, as resolution may involve changes to Apple's software.
Please file a bug report that includes a Xcode project and some directions that can be used to reproduce the problem. And after that please post the bug number here. I'll check the status and provide an update (if there's anything to report) next time I do a sweep of forums posts where I've suggested bug reports.