GenericColorTests.swift

import XCTest
@testable import GenericColor

enum OSVersion {
  case iOS, macOS, unknown
}

#if os(macOS)
import AppKit
let osVersion = OSVersion.macOS
#elseif os(iOS)
import UIKit
let osVersion = OSVersion.iOS
#else
let osVersion = OSVersion.unknown
#endif

final class GenericColorsTests: XCTestCase {
  
  // test default init
  var defaultColor: Color<RGB> = .init(
    red: .byte(250),
    green: .byte(104),
    blue: .byte(120),
    alpha: .byte(255)
  )
  var testableCollection: [(desc: String, color: Color<RGB>)] = []
  
  override func setUp() {
    var color = defaultColor
    testableCollection.append(("{ r: 250, g: 104, b: 120, a: 1 }", color))
    
    color = Color(rgb: 0xfa6878)! // color from 6-digit hex rgb
    testableCollection.append(("Color(rgb: 0xfa6878)", color))
    
    color = Color(rgba: 0xfa6878ff)! // color from 8-digit hex rgb
    testableCollection.append(("Color(rgba: 0xfa6878ff)", color))
    
    color = .hex(rgb: 0xfa6878)! // color from 6-digit hex rgb
    testableCollection.append(("Color.hex(rgb: 0xfa6878)", color))
    
    color = .hex(rgba: 0xfa6878ff)! // color from 8-digit hex rgb
    testableCollection.append(("Color.hex(rgba: 0xfa6878ff)", color))
    
    // case-insensitive string color initializers
    let base = ["fa6878", "fa6878ff", "#fa6878", "#fa6878ff"] // use hash prefix if you want
    let colorStrings = base + base.map{ $0.uppercased() }
    testableCollection += colorStrings.map { ("Color(hex:\($0))", Color(hex: $0)!) }
    testableCollection += colorStrings.map { ("Color.hex(\($0))", .hex($0)!) }
  }
  
  func testInitializers() {
    // let literal: Color<RGB> = #colorLiteral(red: 0.9803921568627451, green: 0.40784313725490196, blue: 0.47058823529411764, alpha: 1)
    // XCTAssertEqual(literal, defaultColor)
    
    // test setup initializers
    testableCollection.forEach { XCTAssertEqual(defaultColor, $0.color, $0.desc) }
    
    // test other initializers
    // color from 3-digit hex rgb
    XCTAssertEqual(Color(hex: "abc"), Color(hex: "abcf"))
    XCTAssertEqual(Color(hex: "abc"), Color(hex: "#abcf"))
    XCTAssertEqual(Color(hex: "abc"), Color(hex: "aabbcc"))
    XCTAssertEqual(Color(hex: "abc"), Color(hex: "#aabbcc"))
    XCTAssertEqual(Color(hex: "abc"), Color(hex: "aabbccff"))
    XCTAssertEqual(Color(hex: "abc"), Color(rgba: 0xaabbccff))
    
    XCTAssertEqual(Color(hex: "#abc"), Color(hex: "ABC"))
    XCTAssertEqual(Color(hex: "#abc"), Color(rgba: 0xAABBCCFF))
    
    // 2 will be rounded to `.max` value
    XCTAssertEqual(Color<RGB>(white: 2), Color(red: .max, green: .max, blue: .max))
  }
  
  func testRgbToHsb() {
    let color = Color<HSB>(
      hue: 0.9817351598173516,
      saturation: 0.584,
      brightness: 0.9803921568627453952,
      alpha: 1
    )
    XCTAssertEqual(defaultColor.hsb, color.container)
    XCTAssertEqual(defaultColor.map(\.hsb), color)
    XCTAssertEqual(defaultColor.convert(), color)
  }
  
  func testHsbToRgb() {
    let color = Color<HSB>(
      hue: 0.9817351598173516,
      saturation: 0.584,
      brightness: 0.9803921568627453952,
      alpha: 1.0
    )
    XCTAssertEqual(color.rgb, defaultColor.container)
    XCTAssertEqual(color.map(\.rgb), defaultColor)
    XCTAssertEqual(color.convert(), defaultColor)
  }
  
  func testRgbToCmyk() {
    let color = Color<CMYK>(
      cyan: .zero,
      magenta: 0.584,
      yellow: 0.52,
      key: 0.01960784313725460992,
      alpha: .max
    )
    XCTAssertEqual(defaultColor.cmyk, color.container)
    XCTAssertEqual(defaultColor.map(\.cmyk), color)
    XCTAssertEqual(defaultColor.convert(), color)
  }
  
  func testCmykToRgb() {
    let color = Color<CMYK>(
      cyan: .zero,
      magenta: 0.584,
      yellow: 0.52,
      key: 0.01960784313725460992,
      alpha: .max
    )
    XCTAssertEqual(color.rgb, defaultColor.container)
    XCTAssertEqual(color.map(\.rgb), defaultColor)
    XCTAssertEqual(color.convert(), defaultColor)
  }
  
  func testCoding() {
    guard let data = try? JSONEncoder().encode(defaultColor)
    else { return XCTFail("Could not encode color.") }
    guard let color = try? JSONDecoder().decode(Color<RGB>.self, from: data)
    else { return XCTFail("Could not decode color.") }
    XCTAssertEqual(color, defaultColor)
  }
  
  func testHexStringRepresentation() {
    let color1 = Color<RGB>.hex(rgb: 0x00aabb)!
    let color2 = Color<RGB>.hex(rgba:0x000)!
    let color3 = Color<RGB>.hex(rgb: 0xffffff)!
    let color4 = Color<RGB>.hex(rgba: 0xffffffaa)!
    
    XCTAssertEqual(color1.hex(uppercase: true, hashTagPrefix: true), "#00AABBFF")
    XCTAssertEqual(color2.hex(uppercase: false, hashTagPrefix: false), "00000000")
    XCTAssertEqual(color3.hex(uppercase: false, hashTagPrefix: true), "#ffffffff")
    XCTAssertEqual(color4.hex(), "ffffffaa")
  }
  
  /// Should not couse initializer ambiguity
  func testMacOSColorInit() throws {
    try XCTSkipUnless(osVersion == .macOS, "MacOS only test")
    #if os(macOS)
    let genericColor = Color<RGB>()
    _ = NSColor(genericColor)
    #endif
  }
  
  /// Should not couse initializer ambiguity
  func testIOSColorInit() throws {
    try XCTSkipUnless(osVersion == .iOS, "iOS only test")
    #if os(iOS)
    let genericColor = Color<RGB>()
    _ = UIColor(genericColor)
    #endif
  }
}