Type-safe Array Init

Prefer using Array(seq) over seq.map { $0 } to convert a sequence into an Array

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

  Key	Value
  severity	warning

Non Triggering Examples

enum MyError: Error {}
let myResult: Result<String, MyError> = .success("")
let result: Result<Any, MyError> = myResult.map { $0 }

struct IntArray {
    let elements = [1, 2, 3]
    func map<T>(_ transformer: (Int) throws -> T) rethrows -> [T] {
        try elements.map(transformer)
    }
}
let ints = IntArray()
let intsCopy = ints.map { $0 }

Triggering Examples

func f<Seq: Sequence>(s: Seq) -> [Seq.Element] {
    s.↓map({ $0 })
}

func f(array: [Int]) -> [Int] {
    array.↓map { $0 }
}

let myInts = [1, 2, 3].↓map { return $0 }

struct Generator: Sequence, IteratorProtocol {
    func next() -> Int? { nil }
}
let array = Generator().↓map { i in i }