Testing removing from pool in swift using Then

poolTests.swift

// Pool tests
// @richy486

// using Then
// https://github.com/devxoul/Then

public protocol Then {}
extension Then {
    
    /// Makes it available to set properties with closures just after initializing.
    ///
    ///     let label = UILabel().then {
    ///         $0.textAlignment = .Center
    ///         $0.textColor = UIColor.blackColor()
    ///         $0.text = "Hello, World!"
    ///     }
    public func then(@noescape block: Self -> Void) -> Self {
        block(self)
        return self
    }
    
}

extension NSObject: Then {}
extension Item: Then {}


// -------- Pool Tests ---------



struct Item {
    var active = true
}

var arr = [Item(active: false),Item(active: false),Item(active: false)]
let poolSize = 20

func getFromPool() -> Item {

    if arr.count >= poolSize {
        let filtered = arr.filter { $0.active == true }
        if filtered.count > 0 {
            return filtered[0]
        }
        
    }
    
    
    
    let newItem = Item(active: true)
    arr.append(newItem)
    return newItem
    
}



func getFromPool2() -> Item {
    
    guard let filtered = (arr.filter { $0.active }).first where arr.count >= poolSize else {
        let newItem = Item(active: true)
        arr.append(newItem)
        return newItem
    }

    return filtered
    
    
    
}


func getFromPool3() -> Item {
    
    guard let filtered = (arr.filter { $0.active }).first where arr.count >= poolSize else {
        return Item(active: true).then{ arr.append($0) }
    }
    
    return filtered
    
    
}

func getFromPool4() -> Item {
    
    return (arr.filter { $0.active }).first ?? Item(active: true).then{ arr.append($0) }
}

// Old way
func getFromPoolNil() -> Item? {
    var item: Item?
    
    if arr.count >= poolSize {
        let filtered = arr.filter { $0.active == true }
        if filtered.count > 0 {
            item = filtered[0]
        }
    }
    
    if item == nil {
        item = Item(active: true)
        arr.append(item!)
    }
    
    return item
}