func logToDisk(_ message: String) {
    DispatchQueue.main.async {
        // Prefix message with date
        let dateFormatter = DateFormatter()
        dateFormatter.dateFormat = "yyyy-MM-dd HH:mm:ss.SSS"

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

func Log(level: ErrorLevel, message: String) {
    #if DEBUG
    print("\(message)\n")
    #endif

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

func rollLogIfNeeded() {
    let cacheDirectory = Cache.supportPath
    // if let cacheDirectory = path() {
    var cacheFileUrl = URL(fileURLWithPath: cacheDirectory as String)
    

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

func logToConsole(_ message: String) {
    if #available(OSX 10.12, *) {
        // This is faster when available
        let log = OSLog(subsystem: Bundle.main.bundleIdentifier!, category: "Screensaver")
        os_log("Aerial: %{public}@", log: log, type: .default, message)

Close

Duplicated Code

Duplicated code can lead to software that is hard to understand and difficult to change. The Don't Repeat Yourself (DRY) principle states:

Every piece of knowledge must have a single, unambiguous, authoritative representation within a system.

When you violate DRY, bugs and maintenance problems are sure to follow. Duplicated code has a tendency to both continue to replicate and also to diverge (leaving bugs as two similar implementations differ in subtle ways).

Tuning

This issue has a mass of 61.

We set useful threshold defaults for the languages we support but you may want to adjust these settings based on your project guidelines.

The threshold configuration represents the minimum mass a code block must have to be analyzed for duplication. The lower the threshold, the more fine-grained the comparison.

If the engine is too easily reporting duplication, try raising the threshold. If you suspect that the engine isn't catching enough duplication, try lowering the threshold. The best setting tends to differ from language to language.

See codeclimate-duplication's documentation for more information about tuning the mass threshold in your .codeclimate.yml.

Refactorings

• Extract Method
• Extract Class
• Form Template Method
• Introduce Null Object
• Pull Up Method
• Pull Up Field
• Substitute Algorithm

Further Reading

• Don't Repeat Yourself on the C2 Wiki
• Duplicated Code on SourceMaking
• Refactoring: Improving the Design of Existing Code by Martin Fowler. Duplicated Code, p76

    if level == .error {
        if #available(OSX 10.12, *) {
            // This is faster when available
            let log = OSLog(subsystem: Bundle.main.bundleIdentifier!, category: "Screensaver")
            os_log("AerialError: %{public}@", log: log, type: .error, message)

Close

Duplicated Code

Duplicated code can lead to software that is hard to understand and difficult to change. The Don't Repeat Yourself (DRY) principle states:

Every piece of knowledge must have a single, unambiguous, authoritative representation within a system.

When you violate DRY, bugs and maintenance problems are sure to follow. Duplicated code has a tendency to both continue to replicate and also to diverge (leaving bugs as two similar implementations differ in subtle ways).

Tuning

This issue has a mass of 61.

We set useful threshold defaults for the languages we support but you may want to adjust these settings based on your project guidelines.

The threshold configuration represents the minimum mass a code block must have to be analyzed for duplication. The lower the threshold, the more fine-grained the comparison.

If the engine is too easily reporting duplication, try raising the threshold. If you suspect that the engine isn't catching enough duplication, try lowering the threshold. The best setting tends to differ from language to language.

See codeclimate-duplication's documentation for more information about tuning the mass threshold in your .codeclimate.yml.

Refactorings

• Extract Method
• Extract Class
• Form Template Method
• Introduce Null Object
• Pull Up Method
• Pull Up Field
• Substitute Algorithm

Further Reading

• Don't Repeat Yourself on the C2 Wiki
• Duplicated Code on SourceMaking
• Refactoring: Improving the Design of Existing Code by Martin Fowler. Duplicated Code, p76

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 Log(level: ErrorLevel, message: String) {

Close

lower-camel-case

method and var names should follow lowerCamelCase naming convention: first letter of the entire word is lowercase, but subsequent first letters are uppercase.

Method and selector names

Preferred

func someMethod() {
    // method definition goes here
}

Not Preferred

func some-method() {
    // method definition goes here
}

Variable names

Preferred

var someVariable = someValue

Not Preferred

var Some_Var1able = someValue

}*/

Close

comment-whitespace

Prefer at least one whitespace character after a comment opening symbol (//, ///, /*, or /**) and at least one whitespace character before a comment closing symbol (*/).

Preferred

// This is a comment

/// This is a documentation comment

/* This is a
multi-line comment */

/* This is a
multi-line comment
*/

/** This is a
documentation multi-line
comment
*/

Not Preferred

//This is a comment

///This is a documentation comment

/*This is a
multi-line comment*/

/**This is a multi-line
documentation comment */

            if (fileSize > 1000000) {

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()
}

}

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
}

    func addCallback(_ callback:@escaping LoggerCallback) {

Close

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••¬

func logToDisk(_ message: String) {

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
}

    }

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
}

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••¬