Some useful regex extension methods for the String type

String+Regex.swift

// MARK: - Regex extensions
extension String {

    func test(for pattern: String, options: NSRegularExpression.Options = []) -> Bool {
        guard let groups = try? matches(for: pattern, options: options) else { return false }
        return groups.count >= 1
    }

    func matches(for pattern: String, options: NSRegularExpression.Options = []) throws -> [[String]] {
        let regex = try NSRegularExpression(pattern: pattern, options: options)
        let matches = regex.matches(in: self, options: [], range: NSRange(location: 0, length: self.utf16.count))
        let nsString = self as NSString
        return matches.map { match in
            return (0..<match.numberOfRanges).map { index in
                let range = match.range(at: index)
                return range.location != NSNotFound ? nsString.substring(with: range) : ""
            }
        }
    }

    func replacingOccurrences(ofPattern pattern: String, with replacement: String,
                              options: NSRegularExpression.Options = []) throws -> String {
        let regex = try NSRegularExpression(pattern: pattern, options: options)
        let matches = regex.matches(in: self, options: [], range: NSRange(location: 0, length: self.utf16.count))
        return matches.reversed().reduce(self) { (string, match) in
            return (string as NSString).replacingCharacters(in: match.range, with: replacement)
        }
    }
}