Swift text height calculation

string.swift

import UIKit
import XCTest
import PlaygroundSupport

extension String {
    func height(withWidth width: CGFloat, font: UIFont) -> CGFloat {
        let linesToCalculate = components(separatedBy: "\n")
        var textHeight: CGFloat = 0
        linesToCalculate.forEach { string in
            let maxSize = CGSize(width: width, height: CGFloat.greatestFiniteMagnitude)
            let actualSize = string.boundingRect(with: maxSize, options: [.usesLineFragmentOrigin], attributes: [NSAttributedString.Key.font: font], context: nil)
            textHeight += actualSize.height
        }
        return textHeight
    }
}

let textWidth: CGFloat = 100
let defaultTextHeight: CGFloat = 334.140625
let textWithNewLinesHeight: CGFloat = 350.84765625
let emptyTextHeight: CGFloat = 16.70703125
let frenceTextHeight: CGFloat = 284.01953125
let defaultText = "Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat."
let textWithNewLines = "Lorem ipsum\n dolor sit amet,\n consectetur adipiscing elit,\n sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.\n Ut enim ad minim veniam,\n quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. "
let frenchText = "Informations détaillées sur le niveau de sécurité de chaque trajet. Obtenez des alertes en cas de conduite agressive, d'accélération rapide, de freinage brutal, de pointes de vitesse ou d'utilisation du téléphone."
let font = UIFont.systemFont(ofSize: 14, weight: .semibold)

func testDefaultTextCalculation() {
    let height = defaultText.height(withWidth: textWidth, font: font)
    let heightWithNewLines = textWithNewLines.height(withWidth: textWidth, font: font)
    let emtyText = "".height(withWidth: textWidth, font: font)
    XCTAssertEqual(height, defaultTextHeight)
    XCTAssertEqual(heightWithNewLines, textWithNewLinesHeight)
    XCTAssertEqual(emtyText, emptyTextHeight)
}
let frenchTextHeight = frenchText.height(withWidth: textWidth, font: font)
let label = UILabel(frame: CGRect(origin: .zero, size: CGSize(width: textWidth, height: frenchTextHeight)))
label.text = frenchText
label.backgroundColor = .white
label.font = font
label.numberOfLines = 0
//PlaygroundPage.current.liveView = label

let textView = UITextView(frame: CGRect(origin: .zero, size: CGSize(width: textWidth, height: defaultTextHeight)))
textView.text = defaultText
textView.font = font
textView.contentInset
//textView.textContainer.lineFragmentPadding = 0
//textView.textContainerInset = .zero
PlaygroundPage.current.liveView = textView


testDefaultTextCalculation()