vm.swift

extension LinearGradient {
    static func addLinearGradient(
        colors: [Color] =  [
            Color(UIColor.alphaVariant40.withAlphaComponent(0.2)),
            Color(UIColor.alphaVariant39)
        ]) -> LinearGradient {
            return LinearGradient(
                gradient: Gradient(colors: colors),
                startPoint: .bottomLeading,
                endPoint: .topTrailing
            )
        }
}


struct GradientBorder: ViewModifier {

    let cornerRadius: CGFloat

    func body(content: Content) -> some View {
        content
            .overlay(
                RoundedRectangle(cornerRadius: cornerRadius)
                    .stroke(
                        LinearGradient.addLinearGradient(),
                        lineWidth: CGFloat(2.0)
                    )
            )
    }
}

extension View {
    func gradientBorder(cornerRadius: CGFloat = CGFloat(12.0)) -> some View {
        modifier(GradientBorder(cornerRadius: cornerRadius))
    }
}