SwiftUI main thread hang detector: https://wadetregaskis.com/swiftui-main-thread-hang-detector/

hang.swift

// https://wadetregaskis.com/swiftui-main-thread-hang-detector/

var body: some View {
    SomeRootView {
        …
    }.task {
        let approximateGranularity = Duration.milliseconds(10)
        let threshold = Duration.milliseconds(50)

        let clock = SuspendingClock()
        var lastIteration = clock.now

        while !Task.isCancelled {
            try? await Task.sleep(for: approximateGranularity,
                                  tolerance: approximateGranularity / 2,
                                  clock: clock)

            let now = clock.now

            if now - lastIteration > threshold {
                print("Main thread hung for \((now - lastIteration).formatted(.units(width: .wide, fractionalPart: .show(length: 2)))).")
            }

            lastIteration = now
        }
    }
}