Quick test to verify SwiftUI Gestures + Velocity

GestureSwitch.swift

import SwiftUI
import UIKit
import PlaygroundSupport

struct GestureSwitch: View {

  @GestureState var offsetY: CGFloat? = nil

  var body: some View {
    ZStack {
      Rectangle()
        .foregroundColor(.gray)

      Rectangle()
        .foregroundColor(.purple)
        .offset(x: 0.0, y: offsetY ?? 0.0)
        .animation(offsetY == nil ? .spring(response: 0.95, dampingFraction: 0.85, blendDuration: 0.0) : nil)
        .gesture(
          DragGesture()
            .updating($offsetY) { (gestureValue, offsetY, _) in
              offsetY = gestureValue.translation.height
            }
        )
    }
  }

}

PlaygroundPage.current.setLiveView(GestureSwitch())
PlaygroundPage.current.needsIndefiniteExecution = true