perform_target.swift

extension XCTestCase {
    public func perform(event: UIControl.Event, from button: UIControl, target: NSObject, args: Any?) {
        let action = button.actions(forTarget: target, forControlEvent: event)?.first ?? ""
        target.performSelector(onMainThread: Selector(action), with: args, waitUntilDone: true)
    }

    public func performGestureRecognizer<T>(type: T.Type, on view: UIView) {
        let gesture = view.gestureRecognizers?.first { $0 is T }

        let target = (gesture?.value(forKey: "_targets") as? [NSObject])?.first
        let selectorString = String(describing: target)
            .components(separatedBy: ", ")
            .first?
            .replacingOccurrences(of: "(action=", with: "")
            .replacingOccurrences(of: "Optional(", with: "") 
            ?? ""

        view.perform(.init(stringLiteral: selectorString))
    }
}