Opening Brace Spacing

The correct positioning of braces that introduce a block of code or member list is highly controversial. No matter which style is preferred, consistency is key. Apart from different tastes, the positioning of braces can also have a significant impact on the readability of the code, especially for visually impaired developers. This rule ensures that braces are preceded by a single space and on the same line as the declaration. Comments between the declaration and the opening brace are respected. Check out the contrasted_opening_brace rule for a different style.

• Identifier: opening_brace
• Enabled by default: Yes
• Supports autocorrection: Yes
• Kind: style
• Analyzer rule: No
• Minimum Swift compiler version: 5.0.0
• Default configuration:

  Key	Value
  severity	warning
  ignore_multiline_type_headers	false
  ignore_multiline_statement_conditions	false
  ignore_multiline_function_signatures	false
  allow_multiline_func	false

Non Triggering Examples

func abc() {
}

[].map() { $0 }

[].map({ })

if let a = b { }

while a == b { }

guard let a = b else { }

struct Rule {}

struct Parent {
    struct Child {
        let foo: Int
    }
}

func f(rect: CGRect) {
    {
        let centre = CGPoint(x: rect.midX, y: rect.midY)
        print(centre)
    }()
}

func f(rect: CGRect) -> () -> Void {
    {
        let centre = CGPoint(x: rect.midX, y: rect.midY)
        print(centre)
    }
}

func f() -> () -> Void {
    {}
}

class Rule:
  NSObject {
  var a: String {
    return ""
  }
}

self.foo(
    (
        "String parameter",
        { "Do something here" }
    )
)

let pattern = #/(\{(?<key>\w+)\})/#

if c {}
else {}

    if c /* comment */ {
        return
    }

Triggering Examples

func abc()↓{
}

func abc()
    ↓{ }

func abc(a: A,
    b: B)
↓{

[].map()↓{ $0 }

struct OldContentView: View {
  @State private var showOptions = false

  var body: some View {
    Button(action: {
      self.showOptions.toggle()
    })↓{
      Image(systemName: "gear")
    }
  }
}

struct OldContentView: View {
  @State private var showOptions = false

  var body: some View {
    Button(action: {
      self.showOptions.toggle()
    })
   ↓{
      Image(systemName: "gear")
    }
  }
}

struct OldContentView: View {
  @State private var showOptions = false

  var body: some View {
    Button {
      self.showOptions.toggle()
    } label:↓{
      Image(systemName: "gear")
    }
  }
}

if let a = b↓{ }

while a == b↓{ }

guard let a = b else↓{ }

if
    let a = b,
    let c = d
    where a == c↓{ }

while
    let a = b,
    let c = d
    where a == c↓{ }

guard
    let a = b,
    let c = d
    where a == c else↓{ }

struct Rule↓{}

struct Rule
↓{
}

struct Rule

    ↓{
}

struct Parent {
    struct Child
    ↓{
        let foo: Int
    }
}

switch a↓{}

if
    let a = b,
    let c = d,
    a == c
↓{ }

while
    let a = b,
    let c = d,
    a == c
↓{ }

guard
    let a = b,
    let c = d,
    a == c else
↓{ }

class Rule↓{}

actor Rule↓{}

enum Rule↓{}

protocol Rule↓{}

extension Rule↓{}

class Rule {
  var a: String↓{
    return ""
  }
}

class Rule {
  var a: String {
    willSet↓{

    }
    didSet  ↓{

    }
  }
}

precedencegroup Group↓{
  assignment: true
}

if
    "test".isEmpty
↓{
    // code here
}

func fooFun() {
    let foo: String? = "foo"
    let bar: String? = "bar"

    if
        let foo = foo,
        let bar = bar
    ↓{
        print(foo + bar)
    }
}

if
    let a = ["A", "B"].first,
    let b = ["B"].first
↓{
    print(a)
}

if c  ↓{}
else /* comment */  ↓{}