Why is my SKShapeNode subclass not appearing when I run my app?

Question

I am trying to have objects fall from the top of the screen so I created a FallingBlock subclass that inherits from SKShapeNode. However, whenever I run my code, the blocks do not appear on the screen. I know these blocks are on screen because they come in contact with other objects, but they are unable to be seen. Below is my code:

import SpriteKit

class FallingBlock: SKShapeNode {
  
    let color = [UIColor.red,UIColor.cyan,UIColor.green,UIColor.yellow,UIColor.orange,UIColor.systemPink].randomElement() as! UIColor
    
    init(side: CGPoint) {
        super.init()
        
        self.path = CGPath(roundedRect: CGRect(x: side.x, y: side.y, width: 20, height: 20), cornerWidth: 3, cornerHeight: 3, transform: nil)
        self.fillColor = color
        self.strokeColor = color
        self.position = side
        self.physicsBody = SKPhysicsBody(rectangleOf: CGSize(width: 20, height: 20))
        self.physicsBody?.affectedByGravity = true
        self.zPosition = 1
        
        self.physicsBody?.categoryBitMask = PhysicsCategories.obstacleCategory
        self.name = ObjectNames.obstacle
        
    }
  
    required init?(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
    
    deinit {
        print("falling block reference deleted")
    }
}

Within my GameScene I am running the following function:

func newObstacle() {
        let side = [25,frame.width-25].randomElement() as! CGFloat
        obstacle = FallingBlock(side: CGPoint(x: side, y: frame.maxY+15))
        worldNode.addChild(obstacle)
        deallocateObstacle()
    }

Answer 1

I couldn't figure out a solution when the class inherits from an SKShapeNode; however, I was able to figure out how to do it when it inherits from an SKNode. All that is required is to initialize the SKNode and then add an SKShapeNode - with your desired attributes - as a child of the SKNode like what is done below:

class FallingBlock: SKNode {
 
    init(side: CGPoint) {
        super.init()
        self.addNewBlock(side)
    }
    
    required init?(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
    
    deinit {
        print("falling block reference deleted")
    }
    
    private func addNewBlock(_ side: CGPoint) {
        var color = [UIColor.red,UIColor.cyan,UIColor.green,UIColor.yellow,UIColor.orange,UIColor.systemPink].randomElement() as! UIColor

        let obstacle = SKShapeNode(rectOf: CGSize(width: 20, height: 20), cornerRadius: 3)
        obstacle.fillColor = color
        obstacle.strokeColor = color
        obstacle.position = side
        obstacle.physicsBody = SKPhysicsBody(rectangleOf: CGSize(width: 20, height: 20))
        obstacle.physicsBody?.affectedByGravity = true
        obstacle.zPosition = 1
        
        obstacle.physicsBody?.categoryBitMask = PhysicsCategories.obstacleCategory
        obstacle.name = ObjectNames.obstacle
        self.addChild(obstacle)
    }
}