Contrasted Opening Brace

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 on a separate line after the declaration to contrast the code block from the rest of the declaration. Comments between the declaration and the opening brace are respected. Check out the opening_brace rule for a different style.

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

  Key	Value
  severity	warning

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
{
    {}
}

@MyProperty 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
    }

if c1
{
  return
} else if c2
{
  return
} else if c3
{
  return
}

let a = f.map
{ a in
    a
}

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")
    } label: ↓{
      Image(systemName: "gear")
    }
  }
}

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

@MyProperty class Rule
{
  var a: String
  {
    willSet↓{

    }
    didSet  ↓{

    }
  }
}

precedencegroup Group ↓{
  assignment: true
}

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

if c  ↓{}
else /* comment */  ↓{}

if c
  ↓{
    // code here
}

if c1 ↓{
  return
} else if c2↓{
  return
} else if c3
 ↓{
  return
}

func f()
{
    return a.map
            ↓{ $0 }
}

a ↓{
    $0
} b: ↓{
    $1
}