What did you do?

Trying to create a showAnimatedSkeleton, where solid color animation change from one color to another:

What did you expect to happen?

Views displaying custom backgroundColor CAAnimation.

What happened instead?

Skeletonable views take default color (clouds) while animation is on, and custom animation is ignored.

Steps to reproduce the behavior

1. Implement showAnimatedSkeleton as follows works fine (using default solid animation):

extension UIView {
    func showSkeletonLoader(cornerRadius: Float = 8) {
        let color = UIColor(red: 0.97, green: 0.98, blue: 1.00, alpha: 1.00)
        SkeletonAppearance.default.multilineHeight = 8
        SkeletonAppearance.default.multilineSpacing = 10
        SkeletonAppearance.default.multilineLastLineFillPercent = 70
        SkeletonAppearance.default.multilineCornerRadius = 8
        self.skeletonCornerRadius = cornerRadius
        return self.showAnimatedSkeleton(usingColor: color, transition: .crossDissolve(0.25))
    }
}

2. Modifying function, adding custom animation:

extension UIView {
    func showSkeletonLoader(cornerRadius: Float = 8) {
        //let color = UIColor(red: 0.87, green: 0.88, blue: 0.94, alpha: 1.00)
        SkeletonAppearance.default.multilineHeight = 8
        SkeletonAppearance.default.multilineSpacing = 10
        SkeletonAppearance.default.multilineLastLineFillPercent = 70
        SkeletonAppearance.default.multilineCornerRadius = 8
        self.skeletonCornerRadius = cornerRadius
        return self.showAnimatedSkeleton(animation: { (layer) -> CAAnimation in
            let darkerColor = UIColor(red: 222.0 / 255.0, green: 225.0 / 255.0, blue: 239.0 / 255.0, alpha: 1.0)
            let lighterColor = UIColor(red: 0.97, green: 0.98, blue: 1.00, alpha: 1.00)
            let pulseAnimation = CABasicAnimation(keyPath: #keyPath(CALayer.backgroundColor))
            pulseAnimation.fromValue = darkerColor
            pulseAnimation.toValue = lighterColor
            pulseAnimation.duration = 1
            pulseAnimation.timingFunction = CAMediaTimingFunction(name: CAMediaTimingFunctionName.easeInEaseOut)
            pulseAnimation.autoreverses = true
            pulseAnimation.repeatCount = .infinity
            pulseAnimation.isRemovedOnCompletion = false
            return pulseAnimation
        }, transition: .crossDissolve(0.25))
    }
}

3. Animation stops working

SkeletonView Environment

SkeletonView version: 1.8.7
Xcode version: 11.3
Swift version: 4.0