@objc func mediaRemoteCallback(_ aNotification: Notification?) {
        var album = ""
        var name = ""
        var artist = ""
        var artwork: NSImage?

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Cognitive Complexity

Cognitive Complexity is a measure of how difficult a unit of code is to intuitively understand. Unlike Cyclomatic Complexity, which determines how difficult your code will be to test, Cognitive Complexity tells you how difficult your code will be to read and comprehend.

A method's cognitive complexity is based on a few simple rules:

• Code is not considered more complex when it uses shorthand that the language provides for collapsing multiple statements into one
• Code is considered more complex for each "break in the linear flow of the code"
• Code is considered more complex when "flow breaking structures are nested"

Further reading

• Cognitive Complexity docs
• Cognitive Complexity: A new way of measuring understandability

    @objc func mediaRemoteAppStateChange(_ aNotification: Notification) {
        debugLog("🎧 app state change")
        
        if let userInfo = aNotification.userInfo {
            if let rate = userInfo["kMRMediaRemoteNowPlayingApplicationIsPlayingUserInfoKey"] as? Double {

Close

Cognitive Complexity

Cognitive Complexity is a measure of how difficult a unit of code is to intuitively understand. Unlike Cyclomatic Complexity, which determines how difficult your code will be to test, Cognitive Complexity tells you how difficult your code will be to read and comprehend.

A method's cognitive complexity is based on a few simple rules:

• Code is not considered more complex when it uses shorthand that the language provides for collapsing multiple statements into one
• Code is considered more complex for each "break in the linear flow of the code"
• Code is considered more complex when "flow breaking structures are nested"

Further reading

• Cognitive Complexity docs
• Cognitive Complexity: A new way of measuring understandability

                        if let _artwork = NSImage(data: information["kMRMediaRemoteNowPlayingInfoArtworkData"] as! Data) {

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forced-type-cast

Avoid using the forced form of the type cast operator (as!) because Swift is not able to determine at compile time if the type conversion will succeed. In the event of an unsuccessful conversion, a runtime error will be triggered. The conditional form of the type cast operator (as?) is safer and should be used when possible.

Preferred

if let movie = item as? Movie {
    print("Movie: '\(movie.name)', dir. \(movie.director)")
}

Not Preferred

let movie = item as! Movie
print("Movie: '\(movie.name)', dir. \(movie.director)")

Close

trailing-whitespace

Flag whitespace after the last non-whitespace character on each line until the newline.

Preferred

let number = 42¬

Not Preferred

let number = 42••¬

Close

trailing-whitespace

Flag whitespace after the last non-whitespace character on each line until the newline.

Preferred

let number = 42¬

Not Preferred

let number = 42••¬

Close

trailing-whitespace

Flag whitespace after the last non-whitespace character on each line until the newline.

Preferred

let number = 42¬

Not Preferred

let number = 42••¬

Close

trailing-whitespace

Flag whitespace after the last non-whitespace character on each line until the newline.

Preferred

let number = 42¬

Not Preferred

let number = 42••¬

        MRMediaRemoteGetNowPlayingInfo(DispatchQueue.main, { (information) in

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trailing-closure

Closures that are the last argument of a function should be passed into the function using trailing closure syntax.

Preferred

reversed = names.sort { s1, s2 in return s1 > s2 }

Not Preferred

reversed = names.sort({ s1, s2 in return s1 > s2 })

Close

trailing-whitespace

Flag whitespace after the last non-whitespace character on each line until the newline.

Preferred

let number = 42¬

Not Preferred

let number = 42••¬

Close

trailing-whitespace

Flag whitespace after the last non-whitespace character on each line until the newline.

Preferred

let number = 42¬

Not Preferred

let number = 42••¬

Close

trailing-whitespace

Flag whitespace after the last non-whitespace character on each line until the newline.

Preferred

let number = 42¬

Not Preferred

let number = 42••¬

Close

trailing-whitespace

Flag whitespace after the last non-whitespace character on each line until the newline.

Preferred

let number = 42¬

Not Preferred

let number = 42••¬

    func addCallback(_ callback:@escaping MusicCallback) {

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colon-whitespace

There should be no whitespace preceding the colon, exactly one whitespace after the colon for: * var, class, struct, protocol, extension, func, and tuple declarations * dict literals and types * case statements

However, for conditional expressions there should be a single whitespace before and after the colon.

Variable declarations

Preferred

var x: Int = 2

Not Preferred

var x : Int
var y:   String

Dictionary literals and types

Preferred

var x = [ 'key1': 1, 'key2': 2 ]
var y: [ Int: String ]

Not Preferred

var x = [ 'key1' : 1, 'key2':  3]
var y: [ Int :    String ]

Case statements

Preferred

switch character {
case "a": doSomething(a);
default: alert();
}

Not Preferred

switch character {
case "a" : doSomething(a);
default:     alert();
}

Class, Struct, Protocol, and Extension declarations

Preferred

class ClassName: BaseClass {
}

struct StructName: BaseStruct {
}

protocol ProtocolName: AnotherProtocol {
}

extension TypeName: ProtocolName {
}

Not Preferred

class ClassName : BaseClass {
}

struct StructName:  BaseStruct {
}

protocol ProtocolName:AnotherProtocol {
}

extension TypeName : ProtocolName {
}

Tuple declarations

Preferred

var y = (key: 1, value: 2)

Not Preferred

var y = (key:1, value : 2)

Function declarations

Preferred

func someFunction<t: someclass u: someprotocol>(someT: T, someU: U) {
}</t:>

Not Preferred

func someFunction<t : someclass u:someprotocol>(someT: T, someU: U) {
}</t>

Conditional expressions

Preferred

var x = condition ? a : b

Not Preferred

var x = condition ? a: b
var x = condition ? a   : b

Close

trailing-whitespace

Flag whitespace after the last non-whitespace character on each line until the newline.

Preferred

let number = 42¬

Not Preferred

let number = 42••¬

Close

trailing-whitespace

Flag whitespace after the last non-whitespace character on each line until the newline.

Preferred

let number = 42¬

Not Preferred

let number = 42••¬

Close

trailing-whitespace

Flag whitespace after the last non-whitespace character on each line until the newline.

Preferred

let number = 42¬

Not Preferred

let number = 42••¬

Close

trailing-whitespace

Flag whitespace after the last non-whitespace character on each line until the newline.

Preferred

let number = 42¬

Not Preferred

let number = 42••¬

Close

trailing-whitespace

Flag whitespace after the last non-whitespace character on each line until the newline.

Preferred

let number = 42¬

Not Preferred

let number = 42••¬

    }

Close

function-whitespace

Every function and method declaration should have one blank line before and after itself. An exception to this rule are functions that are declared at the start of a file (only need one blank line after their declaration) or at the end of a file (only need one blank line before their declaration). Comments immediately before a function declaration (no blank lines between them and the function) are considered to be part of the declaration.

Preferred

func function1() {
  var text = 1
  var text = 2
}

function1()

// a comment
func function2() {
  // something goes here
}

struct SomeStruct {

  func function3() {
    // something goes here
  }

  func function4() {
    // something else goes here
  };

}

func function5() {
  // something goes here
}

Not Preferred

func function1() {
  var text = 1
  var text = 2
}
function1()
// a comment
func function2() {
  // something goes here
}

struct SomeStruct {
  func function3() {
    // something goes here
  }

  func function4() {
    // something else goes here
  };
}
func function5() {
  // something goes here
}

                if (info != 0.0) {

Close

redundant-parentheses

Control flow constructs (if, else if, switch, for, while, repeat-while, and guard statements), Exception handling constructs (throw, and do/catch statements), and Initializers (array, dictionary, initializer patterns) should not be enclosed in parentheses.

Additionally, method calls with no parameters and a trailing closure should not have empty parentheses following the method name.

Control flow constructs

• if, else if statement

Preferred

if SomeCondition {

} else if SomeOtherCondition {
}

Not Preferred

if (SomeCondition) {

} else if (SomeOtherCondition) {
}

• switch statement

Preferred

switch SomeData {
    default:
        break
}

Not Preferred

switch (SomeData) {
    default:
        break
}

• for loop

Preferred

for var i = 0; i < 10; i+=1 {

}

Not Preferred

for (var i = 0; i < 10; i+=1) {

}

• while loop

Preferred

while SomeCondition {

}

Not Preferred

while (SomeCondition) {

}

• repeat-while loop

Preferred

repeat {

} while SomeCondition

Not Preferred

repeat {

} while (SomeCondition)

• guard clause

Preferred

guard true else {   }

Not Preferred

guard (true) else {   }

Exception handling constructs

• do/catch statement

Preferred

do  {

} catch SomeException {

}

Not Preferred

do  {

} catch (SomeException) {

}

• throw statement

Preferred

throw SomeException

Not Preferred

throw (SomeException)

Initializers

• array items

Preferred

var shoppingList: [String] = ["Eggs", "Milk"]

Not Preferred

var shoppingList: [String] = [("Eggs"), ("Milk")]

• dictionary items

Preferred

var airports: [String: String] = ["YYZ": "Toronto Pearson", "DUB": "Dublin"]

Not Preferred

var airports: [String: String] = [("YYZ"): ("Toronto Pearson"), ("DUB"): ("Dublin")]

• initializer patterns

Preferred

var x: Int = 2
var y: String = "Sleekbyte"
var x = 2

Not Preferred

var x: Int = (2)
var y: String = ("Sleekbyte")
var x = (2)

Method calls

Preferred

items.map {
  item in item.transform()
}

Not Preferred

items.map() {
  item in item.transform()
}

                        if let _artwork = NSImage(data: information["kMRMediaRemoteNowPlayingInfoArtworkData"] as! Data) {

Close

constant-naming

Global constants should follow either UpperCamelCase or lowerCamelCase naming conventions. Local constants should follow lowerCamelCase naming conventions.

Preferred

let MaxHeight = 42
let maxHeight = 42

Not Preferred

let max_height = 42