multiple collisions or drugging - ios

Question

I have two types of collision. First one is the spaceShip and asteroid (this is already handled) but I can't handle second type of collisions, where my spaceShipLazer hits enemySpaceShips. In second case I have drugging/multiple collisions or sometimes perfect collision.
My enemySpaceShip is an EnemySpaceShip class which is a subclass of SKSpriteNode.
So the question is about second collision. Is has multiple collisions that is not expected. How I can fix it?
func didBeginContact(contact: SKPhysicsContact) {
if contact.bodyA.categoryBitMask == CollisionCategories.PlayerSpaceShip && contact.bodyB.categoryBitMask == CollisionCategories.Asteroid || contact.bodyB.categoryBitMask == CollisionCategories.PlayerSpaceShip && contact.bodyA.categoryBitMask == CollisionCategories.Asteroid {
if !gameOver && !playerWasHit {
playerWasHit = true
self.pauseTheGame()
//spaceShip vs asteroid animation
let fadeOutAction = SKAction.fadeOutWithDuration(0.1)
fadeOutAction.timingMode = SKActionTimingMode.EaseOut
let fadeInAction = SKAction.fadeInWithDuration(0.1)
fadeInAction.timingMode = SKActionTimingMode.EaseOut
let blinkAction = SKAction.sequence([fadeOutAction, fadeInAction])
let blinkRepeatAction = SKAction.repeatAction(blinkAction, count: 3)
let delayAction = SKAction.waitForDuration(0.2)
let gameOverAction = SKAction.runBlock({ () -> Void in
self.gameSettings.lives--
self.gameDelegate?.gameDelegateDidUpdateLives()
if self.gameSettings.lives > 0 {
self.respawn()
} else {
self.gameSettings.recordScores(self.gameSettings.currentScore)
self.gameDelegate?.gameDelegateGameOver(self.gameSettings.currentScore)
self.gameOver = true
self.pauseTheGame()
}
})
let gameOverSequence = SKAction.sequence([blinkRepeatAction, delayAction, gameOverAction])
spaceShipLayer.runAction(gameOverSequence)
}
if soundOn {
let hitSoundAction = SKAction.playSoundFileNamed("hitSound.wav", waitForCompletion: true)
runAction(hitSoundAction)
}
//second case playerLazer vs enemySpaceShip
} else if contact.bodyA.categoryBitMask == CollisionCategories.PlayerLaser && contact.bodyB.categoryBitMask == CollisionCategories.EnemySpaceShip || contact.bodyB.categoryBitMask == CollisionCategories.PlayerLaser && contact.bodyA.categoryBitMask == CollisionCategories.EnemySpaceShip {
contact.bodyA.node?.removeFromParent()
contact.bodyB.node?.removeFromParent()
}
}

Answer 1

I found decision that makes everything perfect:
just second part should be like this:
if
contact.bodyA.categoryBitMask == CollisionCategories.PlayerLaser &&
contact.bodyB.categoryBitMask == CollisionCategories.EnemySpaceShip ||
contact.bodyA.categoryBitMask == CollisionCategories.EnemySpaceShip &&
contact.bodyB.categoryBitMask == CollisionCategories.PlayerLaser
{
contact.bodyA.node?.physicsBody?.categoryBitMask = CollisionCategories.None
contact.bodyB.node?.physicsBody?.categoryBitMask = CollisionCategories.None
contact.bodyA.node?.removeFromParent()
contact.bodyB.node?.removeFromParent()
self.addPoints(5)
}
}
So I've made .None categoryBitMask and applied it after collision detection so now points and spriteNode behavior is correct!