NumberFormatter+Currency.swift

NumberFormatter+Currency.swift

//
//  NumberFormatter+Currency.swift
//  Created by: Jader Feijo
//

import Foundation

extension NumberFormatter {
	public static func formatter(forCurrencyCode currencyCode: String) -> NumberFormatter {
		return NumberFormatter().with { f in
			f.numberStyle = .currency
			f.currencyCode = currencyCode
		}
	}
}

extension String {
	public static func price(_ price: Double, currencyCode: String) -> String? {
		return NumberFormatter.formatter(
			forCurrencyCode: currencyCode
		).string(
			from: NSNumber(value: price)
		)
	}
	
	public func price(_ price: Double) -> String? {
		return String.price(price, currencyCode: self)
	}
}

extension Double {
	public func formattedAs(currencyWithCode currencyCode: String) -> String? {
		return currencyCode.price(self)
	}
}

NumberFormatterCurrencyTests.swift

//
//  NumberFormatterCurrencyTests.swift
//  Created by: Jader Feijo
//

import XCTest

class NumberFormatterCurrencyTests: XCTestCase {
	
	func testNumberFormatter() {
		// British Pounds
		let gbp = NumberFormatter.formatter(forCurrencyCode: "GBP")
		XCTAssertEqual(gbp.string(from: NSNumber(value: 0.0)), formatted(amount: 0.0, currency: "GBP"))
		XCTAssertEqual(gbp.string(from: NSNumber(value: 1.0)), formatted(amount: 1.0, currency: "GBP"))
		XCTAssertEqual(gbp.string(from: NSNumber(value: 10.0)), formatted(amount: 10.0, currency: "GBP"))
		XCTAssertEqual(gbp.string(from: NSNumber(value: 10.5)), formatted(amount: 10.5, currency: "GBP"))
		XCTAssertEqual(gbp.string(from: NSNumber(value: 0.55)), formatted(amount: 0.55, currency: "GBP"))
		XCTAssertEqual(gbp.string(from: NSNumber(value: 0.777)), formatted(amount: 0.777, currency: "GBP"))
		XCTAssertEqual(gbp.string(from: NSNumber(value: 0.774)), formatted(amount: 0.774, currency: "GBP"))
		
		// US Dollars
		let usd = NumberFormatter.formatter(forCurrencyCode: "USD")
		XCTAssertEqual(usd.string(from: NSNumber(value: 0.0)), formatted(amount: 0.0, currency: "USD"))
		XCTAssertEqual(usd.string(from: NSNumber(value: 1.0)), formatted(amount: 1.0, currency: "USD"))
		XCTAssertEqual(usd.string(from: NSNumber(value: 10.0)), formatted(amount: 10.0, currency: "USD"))
		XCTAssertEqual(usd.string(from: NSNumber(value: 10.5)), formatted(amount: 10.5, currency: "USD"))
		XCTAssertEqual(usd.string(from: NSNumber(value: 0.55)), formatted(amount: 0.55, currency: "USD"))
		XCTAssertEqual(usd.string(from: NSNumber(value: 0.777)), formatted(amount: 0.777, currency: "USD"))
		XCTAssertEqual(usd.string(from: NSNumber(value: 0.774)), formatted(amount: 0.774, currency: "USD"))
	}
	
	func testPriceStatic() {
		// British Pounds
		XCTAssertEqual(String.price(0.0, currencyCode: "gbp"), formatted(amount: 0.0, currency: "GBP"))
		XCTAssertEqual(String.price(1.0, currencyCode: "gbp"), formatted(amount: 1.0, currency: "GBP"))
		XCTAssertEqual(String.price(10.0, currencyCode: "gbp"), formatted(amount: 10.0, currency: "GBP"))
		XCTAssertEqual(String.price(10.5, currencyCode: "gbp"), formatted(amount: 10.5, currency: "GBP"))
		XCTAssertEqual(String.price(0.55, currencyCode: "gbp"), formatted(amount: 0.55, currency: "GBP"))
		XCTAssertEqual(String.price(0.777, currencyCode: "gbp"), formatted(amount: 0.777, currency: "GBP"))
		XCTAssertEqual(String.price(0.774, currencyCode: "gbp"), formatted(amount: 0.774, currency: "GBP"))
		
		// US Dollars
		XCTAssertEqual(String.price(0.0, currencyCode: "usd"), formatted(amount: 0.0, currency: "USD"))
		XCTAssertEqual(String.price(1.0, currencyCode: "usd"), formatted(amount: 1.0, currency: "USD"))
		XCTAssertEqual(String.price(10.0, currencyCode: "usd"), formatted(amount: 10.0, currency: "USD"))
		XCTAssertEqual(String.price(10.5, currencyCode: "usd"), formatted(amount: 10.5, currency: "USD"))
		XCTAssertEqual(String.price(0.55, currencyCode: "usd"), formatted(amount: 0.55, currency: "USD"))
		XCTAssertEqual(String.price(0.777, currencyCode: "usd"), formatted(amount: 0.777, currency: "USD"))
		XCTAssertEqual(String.price(0.774, currencyCode: "usd"), formatted(amount: 0.774, currency: "USD"))
	}
	
	func testPriceInstance() {
		// British Pounds
		XCTAssertEqual("GBP".price(0.0), formatted(amount: 0.0, currency: "GBP"))
		XCTAssertEqual("GBP".price(1.0), formatted(amount: 1.0, currency: "GBP"))
		XCTAssertEqual("GBP".price(10.0), formatted(amount: 10.0, currency: "GBP"))
		XCTAssertEqual("GBP".price(10.5), formatted(amount: 10.5, currency: "GBP"))
		XCTAssertEqual("GBP".price(0.55), formatted(amount: 0.55, currency: "GBP"))
		XCTAssertEqual("GBP".price(0.777), formatted(amount: 0.777, currency: "GBP"))
		XCTAssertEqual("GBP".price(0.774), formatted(amount: 0.774, currency: "GBP"))
		
		// US Dollars
		XCTAssertEqual("USD".price(0.0), formatted(amount: 0.0, currency: "USD"))
		XCTAssertEqual("USD".price(1.0), formatted(amount: 1.0, currency: "USD"))
		XCTAssertEqual("USD".price(10.0), formatted(amount: 10.0, currency: "USD"))
		XCTAssertEqual("USD".price(10.5), formatted(amount: 10.5, currency: "USD"))
		XCTAssertEqual("USD".price(0.55), formatted(amount: 0.55, currency: "USD"))
		XCTAssertEqual("USD".price(0.777), formatted(amount: 0.777, currency: "USD"))
		XCTAssertEqual("USD".price(0.774), formatted(amount: 0.774, currency: "USD"))
	}
	
	func testFormattedAs() {
		// British Pounds
		XCTAssertEqual(0.0.formattedAs(currencyWithCode: "GBP"), formatted(amount: 0.0, currency: "GBP"))
		XCTAssertEqual(1.0.formattedAs(currencyWithCode: "GBP"), formatted(amount: 1.0, currency: "GBP"))
		XCTAssertEqual(10.0.formattedAs(currencyWithCode: "GBP"), formatted(amount: 10.0, currency: "GBP"))
		XCTAssertEqual(10.5.formattedAs(currencyWithCode: "GBP"), formatted(amount: 10.5, currency: "GBP"))
		XCTAssertEqual(0.55.formattedAs(currencyWithCode: "GBP"), formatted(amount: 0.55, currency: "GBP"))
		XCTAssertEqual(0.777.formattedAs(currencyWithCode: "GBP"), formatted(amount: 0.78, currency: "GBP"))
		XCTAssertEqual(0.774.formattedAs(currencyWithCode: "GBP"), formatted(amount: 0.77, currency: "GBP"))
		
		// US Dollars
		XCTAssertEqual(0.0.formattedAs(currencyWithCode: "USD"), formatted(amount: 0.0, currency: "USD"))
		XCTAssertEqual(1.0.formattedAs(currencyWithCode: "USD"), formatted(amount: 1.0, currency: "USD"))
		XCTAssertEqual(10.0.formattedAs(currencyWithCode: "USD"), formatted(amount: 10.0, currency: "USD"))
		XCTAssertEqual(10.5.formattedAs(currencyWithCode: "USD"), formatted(amount: 10.5, currency: "USD"))
		XCTAssertEqual(0.55.formattedAs(currencyWithCode: "USD"), formatted(amount: 0.55, currency: "USD"))
		XCTAssertEqual(0.777.formattedAs(currencyWithCode: "USD"), formatted(amount: 0.78, currency: "USD"))
		XCTAssertEqual(0.774.formattedAs(currencyWithCode: "USD"), formatted(amount: 0.77, currency: "USD"))
	}
	
	func formatted(amount: Double, currency: String) -> String? {
		let formatter = NumberFormatter().with { f in
			f.numberStyle = .currency
			f.currencyCode = currency
		}
		return formatter.string(from: NSNumber(value: amount))
	}
}