ReselectTabViewModifier.swift

private struct ReselectTabViewModifier: ViewModifier {
    @Environment(\.didReselectTab) private var didReselectTab

    let visibleAction: (() -> Void)
    let hiddenAction: (() -> Void)?

    @State var isVisible = false

    init(ifVisible visibleAction: @escaping (() -> Void),
         else hiddenAction: (() -> Void)?) {
        self.visibleAction = visibleAction
        self.hiddenAction = hiddenAction
    }

    func body(content: Content) -> some View {
        content
            .isVisible(self.$isVisible)
            .onReceive(didReselectTab.receive(on: RunLoop.main)) { _ in
                if self.isVisible {
                    self.visibleAction()
                } else if let hiddenAction = self.hiddenAction {
                    hiddenAction()
                }
            }
    }
}

extension View {
    public func onReselect(ifVisible visibleAction: @escaping (() -> Void),
                           else hiddenAction: (() -> Void)? = nil) -> some View {
        return self.modifier(ReselectTabViewModifier(ifVisible: visibleAction, else: hiddenAction))
    }
}

extension EnvironmentValues {
    struct DidReselectTabKey: EnvironmentKey {
        static let defaultValue: AnyPublisher<TabSelection, Never> = Empty<TabSelection, Never>().eraseToAnyPublisher()
    }

    var didReselectTab: AnyPublisher<TabSelection, Never> {
        get {
            return self[DidReselectTabKey.self]
        }
        set {
            self[DidReselectTabKey.self] = newValue
        }
    }
}