attribute.swift

//: Playground - noun: a place where people can play

import UIKit
import XCTest

class UserManagerTests: XCTestCase {
    func testConvertToHtml() {
        self.measure {
            let htmlString = String.init(repeating: "<p>I am normal</p><b>asdfasd</b><i>asdfasdfa</i>", count: 1000)
            _ = htmlString.convertHtml()
        }
    }
}

extension String {
    func convertHtml() -> NSAttributedString {

        let modifiedFont = String(format:"<span style=\"font-family: '-apple-system', 'HelveticaNeue'; font-size: 17\">%@</span>", self)
        let data = modifiedFont.data(using: .utf8)!
        return try! NSAttributedString(data: data, options: [NSAttributedString.DocumentReadingOptionKey.documentType:NSAttributedString.DocumentType.html, NSAttributedString.DocumentReadingOptionKey.characterEncoding: String.Encoding.utf8.rawValue], documentAttributes: nil)
    }
}

UserManagerTests.defaultTestSuite.run()

Test Case '-[__lldb_expr_61.UserManagerTests testConvertToHtml]' measured [Time, seconds] average: 0.928, relative standard deviation: 3.961%