Swift Extensions for SKAction.playSoundFileNamed() with custom volume

SKAction+Extensions.swift

// reference: https://github.com/pepelkod/iOS-Examples/blob/master/PlaySoundWithVolume/PlaySoundWithVolumeAction.m

import SpriteKit

public extension SKAction {
    public class func playSoundFileNamed(fileName: String, atVolume: Float, waitForCompletion: Bool) -> SKAction {
        
        let nameOnly = fileName.stringByDeletingPathExtension
        let fileExt  = fileName.pathExtension
        
        let soundPath = NSBundle.mainBundle().URLForResource(nameOnly, withExtension: fileExt)
        
        var error:NSError?
        
        let player: AVAudioPlayer = AVAudioPlayer(contentsOfURL: soundPath, error: &error)
        
        player.volume = atVolume
        
        let playAction: SKAction = SKAction.runBlock { () -> Void in
            player.play()
        }
        
        if(waitForCompletion){
            let waitAction = SKAction.waitForDuration(player.duration)
            let groupAction: SKAction = SKAction.group([playAction, waitAction])
            return groupAction
        }
        
        return playAction
    }
}

Updated for Swift 4.1 :

`public extension SKAction {

    public class func playSoundFileNamed(fileName: String, atVolume: Float, waitForCompletion: Bool) -> SKAction {
    
    let nameOnly = URL(fileURLWithPath: fileName).deletingPathExtension().lastPathComponent
    let fileExt  = fileName.pathExtension
    
    let soundPath = Bundle.main.url(forResource: nameOnly, withExtension: fileExt)
    
    var player: AVAudioPlayer!
    do {
       player = try AVAudioPlayer(contentsOf: soundPath!)
    } catch {
        debugPrint("Error with playing soundFile: \(error.localizedDescription)")
    }
    
    player.volume = atVolume
    
    let playAction: SKAction = SKAction.run { () -> Void in
        player.play()
    }
    
    if(waitForCompletion){
        let waitAction = SKAction.wait(forDuration: player.duration)
        let groupAction: SKAction = SKAction.group([playAction, waitAction])
        return groupAction
    }
    
    return playAction
 }
}

extension String {
    var ns: NSString {
        return self as NSString
    }
    var pathExtension: String {
        return ns.pathExtension
    }
    var lastPathComponent: String {
        return ns.lastPathComponent
    }
}`