Code block below produces different results depending on if print is commented or not: import Combine var cancellables = SetAnyCancellable() enum FruitError: Error { case bad } var fruit = "apple" func getFruit() - String { fruit } Just(getFruit) //.print() .map{$0()} .flatMap { value - AnyPublisherString, FruitError in print("in flat map \(value)") if value == "apple" { fruit = "pineapple" return Fail(error: FruitError.bad).eraseToAnyPublisher() } return Just("banana").setFailureType(to: FruitError.self).eraseToAnyPublisher() } .retry(1) .sink(receiveCompletion: { print($0) }, receiveValue: {print($0)}) .store(in: &cancellables) Without print: in flat map apple in flat map apple failure With print: in flat map apple in flat map pineapple banana receive finished finished receive finished Why does print or any other debug operator(breakpoint or handleEvent) change behaviour of sequence? Playground without print - https://developer.apple.com/forums/content/attachment/d8a1d043-191b-41f3-8f0e-72dafa621374 Playground with print - https://developer.apple.com/forums/content/attachment/7c0de4c2-37fb-4136-ae8e-5ed0e77287c5

We used Locale::usesMetricSystem to distinguish between metric and Imperial(US) measurement systems. We set "-AppleLocale en_US" as launch argument for App in UITests but usesMetricSystem still returns true in case user's locale are not equal to "US" in System Preferences - Language and Region - Region. Here is a demo project to illustrate the issue: https://github.com/yuri-qualtie/UseMetricSystemDemo Precondition: Change user region to not US(for example Australia) in System Preferences - Language and Region - Region We expect that code: print(Locale.current.usesMetricSystem) prints false when -AppleLocale en_US is set but actual result is true Probably there is alternative way how to change measurement system via launch arguments or App's settings in Xcode?

We have SwiftUI Alert with destructive button - "Yes, sign out"? Alert( title: Text("Are you sure you want to sign out?"), message: Text("Some message"), primaryButton: .cancel( Text("No, don’t sign out") ), secondaryButton: .destructive( Text("Yes, sign out"), action: { print("signOut") } ) ) Button's text is displayed in pale pink but according to our design we want to change it to dark red. As an option we want change button's color as well. How we can accomplish it? As a side note: we found that for iOS we probably can utilise UIView.appearance(whenContainedInInstancesOf: API but it's available only on iOS but we are interested in solution for macOS

We were encourage by Frameworks Engineer reply and Apple's Official Docs and started to use this approach in our App. But next we detected that App has leaked objects when we do Memory Graph Check in UITests. Removing of .accessibilityElement(children: .contain) solves the issue but we still want to use container identifiers in our UITests. Here is a sample project to illustrated and reproduce the issue: https://github.com/yuri-qualtie/MemoryLeaks. All the details and steps are described in Readme We need help with fix for .accessibilityElement(children: .contain) but any workaround is welcomed

We updated our CI machine to: macOS Monterey Version 12.0.1 Xcode Version 13.1 (13A1030d) We started to receive UITest failures with following error: Testing failed: MemoryLeaksUITests: MemoryLeaksUITests-Runner (3507) encountered an error (The test runner failed to initialize for UI testing. If you believe this error represents a bug, please attach the result bundle at /Users/dev/Library/Developer/Xcode/DerivedData/MemoryLeaks-dduvihbyiuzwdnawggthtfwdgwks/Logs/Test/Test-MemoryLeaks-2021.11.05_13-43-58-+0300.xcresult. (Underlying Error: Timed out while enabling automation mode.)) The failure disappears if we enable UIAutomation for testmanagerd by providing password However it's not one time action. This permission dialog still appears after some time during a day. We noticed it constantly appears after machine reboot. Unfortunately it blocks us from using our CI machine as test runner. There is no option(checkbox) to permanently enable(provide password) automation in this dialog. Also it's not possible to add it in Settings -> Security & Privacy -> Privacy - Automation. Here is a sample project on GitHub to reproduce the issue. Steps: Reboot machine Run in terminal xcodebuild -target MemoryLeaksUITests -scheme MemoryLeaks test

In following code example: struct ContentView: View {     @State var text: String = "sample text"     var body: some View {         VStack {             TextField("", text: $text)             Button(action: { print("action performed!") }) {                 Text("Click me")             }             .keyboardShortcut(.defaultAction)         }         .padding(40)     } } .keyboardShortcut(.defaultAction) that is attached to Button perfectly works on macOs Big Sur(11.6) and I see "action performed!" in Xcode console when tap Enter key on keyboard. Unfortunately, same example doesn't work on macOs Monterey(12.0.1) and Xcode 13.1. So nothing happens(I don't see any logs) when I tap Enter key on keyboard. Also I noticed that it happens only when focus is set in TextField. I checked that onSubmit can solve this issue. Unfortunately, I can't use since it's available in macOs 12 or newer but my App has deployment target is macOs 11. So any workarounds are welcomed.

We use .xcresult files on our CI and recently noticed that size of file significantly increased. So previously we had files ~ 50 MB but now they are ~ 300 MB. After investigation of .xcresult contents we found that it contains macOS Logs - test-session-systemlogs-2022.01.05_13-13-07-+0000 In testmanagerd .log we see in a last line: Moved logarchive from /var/tmp/test-session-systemlogs-2022.01.05_13-13-07-+0000.logarchive to ../Staging/1_Test/Diagnostics/My Mac_4203018E-580F-C1B5-9525-B745CECA79EB/test-session-systemlogs-2022.01.05_13-13-07-+0000.logarchive Issue is reproducible on a new project. Steps: File -> New -> Project Select macOS -> App Enable include test For simplicity disable(comment) all the UITests except ResultSampleUITests::testExample Add XCTAssertTrue(false) after app.launch() Run tests from console and specify path to resultBundlePath xcodebuild -project ResultSample.xcodeproj -scheme ResultSample -resultBundlePath ~/Downloads/2/all-tests -test-timeouts-enabled YES test 7. When tests are finished navigate to resultBundlePath and check size of all-tests.xcresult. It has size 51.6 MB for me. If change XCTAssertTrue(false) to XCTAssertTrue(true) then size of all-tests.xcresult is decreased to 31 KB. Any idea how to disable/delete macOS diagnostic logs or decrease a size of .xcresult

We inspired by announce that DriverKit will come to iPadOs this fall and decided to experiment with DriverKit on macOS. We started from scratch but followed all the recommendations from Sample. With our installer code we can: Install driver extension to macOS system. (systemextensionsctl list shows [activated enabled]) for our driver See driver record using ioreg. So it's displayed: MyDriver <class IOUserService, id 0x10000193b, registered, matched, active, busy 0 (0 ms), retain 7> See *.MyDriver process in Activity Monitor In client code we can find a match: private let dextIdentifier = "MyDriver" private var lastResult: kern_return_t = kIOReturnSuccess private var connection: io_connect_t = IO_OBJECT_NULL var iterator: io_iterator_t = IO_OBJECT_NULL var driver: io_service_t = IO_OBJECT_NULL lastResult = IOServiceGetMatchingServices(kIOMasterPortDefault, IOServiceNameMatching(dextIdentifier), &iterator) print("Search for services ...") while case let service = IOIteratorNext(iterator), service != IO_OBJECT_NULL { driver = service } IOObjectRelease(iterator) guard driver != IO_OBJECT_NULL else { return } So driver is not IO_OBJECT_NULL. But we stuck on IOServiceOpen. So code: lastResult = IOServiceOpen(driver, mach_task_self_, UInt32(kIOHIDServerConnectType), &connection); validateLastResult(forOperation: "opening service") prints opening service: (iokit/common) general error since IOServiceOpen returns 0x2bc What we tried: Disable SIP in recovery mode and set systemextensionsctl developer on Result: opening service: (iokit/common) general error Add com.apple.developer.driverkit.userclient-access to our client App. Result: App crashes on start and in Console we see: taskgated-helper - Unsatisfied entitlements: com.apple.developer.driverkit.userclient-access. We requested this entitlement. We found post were com.apple.developer.driverkit.allow-any-userclient-access suggested as solution. Result: Driver extension is not started and we see in Console: taskgated-helper MyDriver: Unsatisfied entitlements: com.apple.developer.driverkit.allow-any-userclient-access amfid /Library/SystemExtensions/B7624EEF-3688-4735-A58B-26FEF4DE353C/MyDriver.dext/MyDriver signature not valid: -67671 We recreated appIds, profiles on developer account that has com.apple.developer.driverkit.allow-any-userclient-access from Apple. Result: Driver extension is started but we still see opening service: (iokit/common) general error We modified CommunicatingBetweenADriverKitExtensionAndAClientApp.zip by setting our appIds and profiles and run in in SIP disabled mode. Result: opening service: (iokit/common) general error Our environment: macOS Monterey 12.4 XCode Version 13.4 (13F17a) Driver Code is pretty straightforward: ///// iig class MyDriver: public IOUserClient { public: virtual bool init(void) override; virtual kern_return_t Start(IOService * provider) override; virtual kern_return_t Stop(IOService* provider) override; virtual void free(void) override; }; ///// cpp #define Log(fmt, ...) os_log(OS_LOG_DEFAULT, "MyDriver - " fmt "\n", ##__VA_ARGS__) struct MyDriver_IVars { OSAction* callbackAction = nullptr; }; bool MyDriver::init() { bool result = false; Log("init()"); result = super::init(); if (result != true) { Log("init() - super::init failed."); goto Exit; } ivars = IONewZero(MyDriver_IVars, 1); if (ivars == nullptr) { Log("init() - Failed to allocate memory for ivars."); goto Exit; } Log("init() - Finished."); return true; Exit: return false; } kern_return_t IMPL(MyDriver, Start) { kern_return_t ret; ret = Start(provider, SUPERDISPATCH); if(ret != kIOReturnSuccess) { Log("Start() - super::Start failed with error: 0x%08x.", ret); goto Exit; } ret = RegisterService(); if (ret != kIOReturnSuccess) { Log("Start() - Failed to register service with error: 0x%08x.", ret); goto Exit; } Log("Start() - Finished."); ret = kIOReturnSuccess; Exit: return ret; } kern_return_t IMPL(MyDriver, Stop) { kern_return_t ret = kIOReturnSuccess; Log("Stop()"); ret = Stop(provider, SUPERDISPATCH); if (ret != kIOReturnSuccess) { Log("Stop() - super::Stop failed with error: 0x%08x.", ret); } return ret; } void MyDriver::free(void) { Log("free()"); IOSafeDeleteNULL(ivars, MyDriver_IVars, 1); super::free(); }

We requested com.apple.developer.driverkit.transport.usb entitlement a few days ago and it looks like it was granted since we see(can select) it at: App Id -> Additional Capabilities Tab -> DriverKit USB Transport - Vendor ID. We tried to choose both options at Additional Entitlements page Default and Driver Kit and System Extension Template for **** Mac Dev. Generated profile displays DriverKit USB Transport - Vendor ID in Enabled Capabilities in browser. However downloaded profile doesn't include com.apple.developer.driverkit.transport.usb. As a result our Driver fails to start and in Console we see: Driver: Unsatisfied entitlements: com.apple.developer.driverkit.transport.usb /Library/SystemExtensions/675FA894-8985-4D86-B0FF-B892B9AEA27B/Driver.dext/Driver signature not valid: -67671 BTW, we tried to modify existing profile and create a new one. Did we miss something? Is any way to check entitlement status with Apple support?

We created Driver sample by Xcode template and following macro was added into code: #define Log(fmt, ...) os_log(OS_LOG_DEFAULT, "Driver - " fmt "\n", ##__VA_ARGS__) We used this macro in init and start. For example: bool ForcePlateDriver::init() { Log("init()"); But our logs are not displayed in Console app. Did we miss something? Is anything else is required to have logs for Driver? Our environment: MacOS Monterey - 12.4 (21F79) Xcode - Version 13.4 (13F17a)

We followed WWDC Session: System Extensions and DriverKit and recreated a code to do USB device communication via IOUSBHostPipe: struct MyDriver_IVars {     IOUSBHostInterface       *interface;     IOUSBHostPipe            *inPipe;     OSAction                 *ioCompleteCallback;     IOBufferMemoryDescriptor *inData;     uint16_t                  maxPacketSize; }; kern_return_t IMPL(MyDriver, Start) { ...     ivars->maxPacketSize = 64;     ret = ivars->interface->CreateIOBuffer( kIOMemoryDirectionInOut,                                            ivars->maxPacketSize,                                            &ivars->inData);     ret = CreateActionReadComplete(0, &ivars->ioCompleteCallback); ret = ivars->inPipe->AsyncIO(ivars->inData,                                  ivars->maxPacketSize,                                  ivars->ioCompleteCallback,                                  0); ... } Our Driver is started by OS when device is connected. We see that ReadComplete callback is called: void IMPL(MyDriver, ReadComplete) {     Log("ReadComplete() - status - %d; bytes count - %d", status, actualByteCount); } However it's not obvious how to read data received in this callback. I suspect that we should use IOBufferMemoryDescriptor *inData but we didn't find any good example/sample and documentation is poor. Our callback is called only once. It's not clear how to read a series of data from device? Should we create some loop and call inPipe->AsyncIO from callback? Also it would be helpful to see how to pass data to device. I hope we should fill IOBufferMemoryDescriptor *inData.

We are experimenting with DriverKit on macOS while DriverKit is still in beta on iPadOS. We want to build a Driver for iPad that will allow to communicate our iPad App with USB device. What we did: Configured and implemented a driver that uses USBDriverKit::IOUSBHostInterface as provider. This driver is automatically matched/started by macOS when we plug our device into USB port. Next we utilised USBDriverKit::IOUSBHostPipe to send/receive data from our device. We print data from device in logs for now. Studied Communicating Between a DriverKit Extension and a Client App Configured and implemented a driver that based on IOUserClient and allows to open communication channel by macOs App using IOServiceOpen API. Driver has callback to pass data to macOS Client App. Currently we want to combine 2 drivers and pass data received from USB device to our client App using callback. Unfortunately, we stuck since now we have 2 instances of driver: First instance is automatically run by macOS when device is plugged Second instance is created when we are connecting from Client App and virtual kern_return_t NewUserClient(uint32_t type, IOUserClient** userClient) method is called. So we can't use second instance to do USB device communication since it has wrong provider(IOUserClient) in kern_return_t Start(IOService * provider) but we need IOUSBHostInterface to start:     ivars->interface = OSDynamicCast(IOUSBHostInterface, provider);     if(ivars->interface == NULL) {         ret = kIOReturnNoDevice;         goto Exit;     } Are we doing it wrong? Maybe instead of automatic matching for IOUSBHostInterface we should do it manually from UserClient driver or use another approach? As we learned we have to create a new service instance in NewUserClient method and can't return driver that was run by OS: kern_return_t IMPL(MyDriver, NewUserClient) {     kern_return_t ret = kIOReturnSuccess;     IOService* client = nullptr;     ret = Create(this, "UserClientProperties", &client);     if (ret != kIOReturnSuccess)     {         goto Exit;     }     *userClient = OSDynamicCast(IOUserClient, client);     if (*userClient == NULL)     {         client->release();         ret = kIOReturnError;         goto Exit;     } Exit:     return ret; } BTW, maybe there is much easier way to forward data from USB device to iPadOS App?

According to Communicating Between a DriverKit Extension and a Client App we can use IOConnectCallScalarMethod to send/get data to Driver. We use unchecked variation of IOConnectCallScalarMethod to call method in our Driver from Client App. In a Driver's method we set arguments->scalarOutputCount greater than 16. However in a Client app outputCount equal to 16, so we can get only a portion of output. Is 16 limit enforced by IOConnectCallScalarMethod implementation? How we can get more than 16? Should we use IOConnectCallStructMethod instead?

We implemented communication between Swift App and DriverKit driver using IOConnectCallAsyncStructMethod. So in Swift App we have following code to setup AsyncDataCallback: func AsyncDataCallback(refcon: UnsafeMutableRawPointer?, result: IOReturn, args: UnsafeMutablePointer<UnsafeMutableRawPointer?>?, numArgs: UInt32) -> Void { // handle args } var asyncRef: [io_user_reference_t] = .init(repeating: 0, count: 8) asyncRef[kIOAsyncCalloutFuncIndex] = unsafeBitCast(AsyncDataCallback as IOAsyncCallback, to: UInt64.self) asyncRef[kIOAsyncCalloutRefconIndex] = unsafeBitCast(self, to: UInt64.self) ...... let notificationPort = IONotificationPortCreate(kIOMasterPortDefault) let machNotificationPort = IONotificationPortGetMachPort(notificationPort) let runLoopSource = IONotificationPortGetRunLoopSource(notificationPort)! CFRunLoopAddSource(CFRunLoopGetCurrent(), runLoopSource.takeUnretainedValue(), CFRunLoopMode.defaultMode) var input = "someinput".map { UInt8($0.asciiValue!) } let inputSize = input.count IOConnectCallAsyncStructMethod(             connection,             123,             machNotificationPort,             &asyncRef,             UInt32(kIOAsyncCalloutCount),             &input,             inputSize,             nil,             nil ) In the driver's ExternalMethod we save callback in ivars: ivars->callbackAction = arguments->completion; ivars->callbackAction->retain(); Next we start communication with our device in a separate thread and execute callback when we get data from device: SendDataAsync(void *data, uint32_t dataLength) { const int asyncDataCount = 16; if (ivars->callbackAction != nullptr) {         Log("SendDataAsync() - got %u bytes", dataLength);         uint64_t asyncData[asyncDataCount] = { };         asyncData[0] = dataLength;         memcpy(asyncData + 1, data, dataLength);         AsyncCompletion(ivars->callbackAction, kIOReturnSuccess, asyncData, asyncDataCount);     } Limitation 1: Our device produces data packet every 10 ms. So driver gets 100 data packets per second. Receive rate is good and we verified it by logs. However we see some delay in AsyncCallback in Swift App. It looks like async calls are queued since we see that Swift App gets callbacks for a few seconds when we stopped to send data from Driver. We measured receive rate in Swift App and it is about 50 data packets per second. So what's a minimum call rate for AsyncCompletion? Is it higher than 10 ms? Maybe there is other more efficient way to asynchronously pass data from Driver to Swift App? Limitation 2: We thought we can buffer data packets and decrease AsyncCompletion call rate. However asyncData could be only 16 of uint64_t by declaration typedef uint64_t IOUserClientAsyncArgumentsArray[16];. Size of our data packer is 112 bytes that perfectly fits to max args size(8*16 = 128 bytes). So we can't cache and send 2 data packets. How we can avoid this limitation and send more data via AsyncCompletion? Is there any other API for asynchronous communication that allows send more data back?

We are developing driver for our USB device. Our approach is to run and test driver on macOS first and then verify on iPadOS 16. In the driver we add custom property -"kUSBSerialNumberString" into default properties: OSDictionary * Driver::devicePropertiesWithSerialNumber() {     kern_return_t ret;     OSDictionary *properties = NULL;     OSDictionary *dictionary = NULL;     OSObjectPtr value;     const IOUSBDeviceDescriptor *deviceDescriptor;     deviceDescriptor = ivars->device->CopyDeviceDescriptor();          ret = CopyProperties(&properties);     value = copyStringAtIndex(deviceDescriptor->iSerialNumber, kIOUSBLanguageIDEnglishUS);     Log("Serial number: %{public}s", ((OSString *)value)->getCStringNoCopy());          dictionary = OSDictionary::withDictionary(properties, 0);     OSSafeReleaseNULL(properties);     if (value) {         OSDictionarySetValue(dictionary, "kUSBSerialNumberString", value);         OSSafeReleaseNULL(value);     }     return  dictionary; } next in kern_return_t IMPL(Driver, Start) we call SetProperties:     ret = SetProperties(devicePropertiesWithSerialNumber());     if(ret != kIOReturnSuccess) {         Log("Start() - Failed to set properties: 0x%08x.", ret);         goto Exit;     } We can read our property on macOS using:     func getDeviceProperty(device: io_object_t, key: String) -> AnyObject? {         IORegistryEntryCreateCFProperty(             device, key as CFString, kCFAllocatorDefault, .zero         )?.takeRetainedValue()     }         if let serialNumber = getDeviceProperty(device: driver, key: "kUSBSerialNumberString") {             print("serialNumber: \(serialNumber)")         } However getDevicePropertyon iPadOS returns nil. We are wondering is any limitation for IORegistry entries(properties) on iPadOS16? Is any way to add custom property to IORegistry? BTW, we added debug method to print all the available properties for IORegistry:     private func debugRegistry(device: io_object_t) {         var dictionary: Unmanaged<CFMutableDictionary>?         IORegistryEntryCreateCFProperties(device, &dictionary, kCFAllocatorDefault, .zero)         if let dictionary = dictionary {             let values = dictionary.takeUnretainedValue()             print(values)         }     } It returns just 1 property for iPadOS: { IOClass = IOUserService; } and much more for macOS including our custom one: { CFBundleIdentifier = "****"; CFBundleIdentifierKernel = "com.apple.kpi.iokit"; IOClass = IOUserService; IOMatchCategory = "***"; IOMatchedPersonality = { CFBundleIdentifier = "****"; CFBundleIdentifierKernel = "com.apple.kpi.iokit"; IOClass = IOUserService; IOMatchCategory = "****"; IOPersonalityPublisher = "****"; IOProviderClass = IOUSBHostInterface; IOResourceMatch = IOKit; IOUserClass = Driver; IOUserServerCDHash = 9cfd03b5c1b90da709ffb1455a053c5d7cdf47ac; IOUserServerName = "*****"; UserClientProperties = { IOClass = IOUserUserClient; IOUserClass = DriverUserClient; }; bConfigurationValue = 1; bInterfaceNumber = 1; bcdDevice = 512; idProduct = XXXXX; idVendor = XXXXX; }; IOPersonalityPublisher = "*****"; IOPowerManagement = { CapabilityFlags = 2; CurrentPowerState = 2; MaxPowerState = 2; }; IOProbeScore = 100000; IOProviderClass = IOUSBHostInterface; IOResourceMatch = IOKit; IOUserClass = Driver; IOUserServerCDHash = 9cfd03b5c1b90da709ffb1455a053c5d7cdf47ac; IOUserServerName = "*****"; UserClientProperties = { IOClass = IOUserUserClient; IOUserClass = DriverUserClient; }; bConfigurationValue = 1; bInterfaceNumber = 1; bcdDevice = 512; idProduct = XXXXX; idVendor = XXXXXX; kUSBSerialNumberString = XXXXXXXXXXX; }