Merge pull request #4 from 5sw/figma

Import colors from Figma library

.github/workflows/release.yml

@@ -24,7 +24,7 @@ jobs:
               head "https://github.com/${{ github.repository }}.git"
               license "MIT"
 
-              depends_on :xcode => ["12.0", :build]
+              depends_on :xcode => ["14.0", :build]
 
               def install
                 system "make", "install", "prefix=#{prefix}"

.github/workflows/test.yml

@@ -5,7 +5,7 @@ on:
 
 jobs:
   BuildAndTest:
-    runs-on: macos-latest
+    runs-on: macos-12
     steps:
       - uses: actions/checkout@v1
 

.swift-version

@@ -1 +1 @@
-5.3
+5.7

Example/.gitignore

@@ -0,0 +1,2 @@
+Example.*
+!Example.txt

Example/Example.txt

@@ -0,0 +1,10 @@
+Base/Green #8fd151
+Base/PaleGreen #d0f9a9
+Base/Red rgb(249, 39, 7)
+TransparentRed rgba(255, 0, 0, 128)
+Base/Yellow #ff0
+
+Error @Base/Red
+Warning @Base/Yellow
+Good @Base/Green
+

Package.resolved

@@ -1,16 +1,23 @@
 {
-  "object": {
   "pins" : [
     {
-        "package": "swift-argument-parser",
-        "repositoryURL": "https://github.com/apple/swift-argument-parser",
+      "identity" : "rbbjson",
+      "kind" : "remoteSourceControl",
+      "location" : "https://github.com/robb/RBBJSON",
       "state" : {
-          "branch": null,
-          "revision": "92646c0cdbaca076c8d3d0207891785b3379cbff",
-          "version": "0.3.1"
+        "branch" : "main",
+        "revision" : "102c970283e105d7c5be2e29630db29c808c20eb"
       }
-      }
-    ]
     },
-  "version": 1
+    {
+      "identity" : "swift-argument-parser",
+      "kind" : "remoteSourceControl",
+      "location" : "https://github.com/apple/swift-argument-parser",
+      "state" : {
+        "revision" : "9f39744e025c7d377987f30b03770805dcb0bcd1",
+        "version" : "1.1.4"
+      }
+    }
+  ],
+  "version" : 2
 }

Package.swift

@@ -1,4 +1,4 @@
-// swift-tools-version:5.3
+// swift-tools-version:5.7
 // The swift-tools-version declares the minimum version of Swift required to build this package.
 
 import PackageDescription
@@ -6,27 +6,25 @@ import PackageDescription
 let package = Package(
     name: "MakeColors",
     platforms: [
-        .macOS("10.15.4"),
+        .macOS("12.0"),
     ],
     dependencies: [
-        .package(url: "https://github.com/apple/swift-argument-parser", .upToNextMinor(from: "0.3.1")),
+        .package(url: "https://github.com/apple/swift-argument-parser", .upToNextMinor(from: "1.1.4")),
+        .package(url: "https://github.com/robb/RBBJSON", branch: "main"),
     ],
     targets: [
-        .target(
+        .executableTarget(
             name: "MakeColors",
-            dependencies: [
-                "LibMakeColors",
-            ]
-        ),
-        .target(
-            name: "LibMakeColors",
             dependencies: [
                 .product(name: "ArgumentParser", package: "swift-argument-parser"),
             ]
         ),
         .testTarget(
             name: "MakeColorsTests",
-            dependencies: ["LibMakeColors"]
+            dependencies: [
+                "MakeColors",
+                .product(name: "RBBJSON", package: "RBBJSON"),
+            ]
         ),
     ]
 )

README.md

@@ -45,6 +45,7 @@ Base/Red rgb(249, 39, 7)
 TransparentRed rgba(255, 0, 0, 128)
 Base/Yellow #ff0
 ```
+
 Grayscale colors can be produced with the `white(value)` and `white(value, alpha)` syntax. A value of zero means black while a value of 255 is pure white. 
 
 ```
@@ -53,6 +54,12 @@ MediumGray white(128)
 TransparentGray white(128, 128)
 ```
 
+HSV colors can be specified as `hsv(hue, saturation, value)` or `hsva(hue, saturation, value, alpha)` syntax. Hue is specified as degrees with the `°` or `deg` suffix.
+
+```
+HSV/Yellow hsv(60°, 255, 255)
+```
+
 Colors can also reference other colors by prefixing them with an `@` sign:
 
 ```
@@ -102,7 +109,6 @@ The generated HTML looks like this:
 
 ## Future work
 
-- Support other color formats (HSV, ...)
 - Calculate derived colors (blend, change hue/saturation/brightness/alpha)
 - Support for dark/light mode
 - Improved error reporting in the parser

Sources/MakeColors/Generators/AssetCatalogGenerator.swift

@@ -58,7 +58,7 @@ private let infoTag = """
 }
 """
 
-private extension Color {
+extension Color {
     func json() -> String {
         """
         {
@@ -67,10 +67,10 @@ private extension Color {
             "color" : {
                 "color-space" : "srgb",
                 "components" : {
-                "alpha" : "0x\(String(alpha, radix: 16))",
-                "blue" : "0x\(String(blue, radix: 16))",
-                "green" : "0x\(String(green, radix: 16))",
-                "red" : "0x\(String(red, radix: 16))"
+                "alpha" : "\(Double(alpha) / 0xFF)",
+                "blue" : "0x\(blue, radix: 16, width: 2)",
+                "green" : "0x\(green, radix: 16, width: 2)",
+                "red" : "0x\(red, radix: 16, width: 2)"
                 }
             },
             "idiom" : "universal"
@@ -88,6 +88,22 @@ private extension Color {
     }
 }
 
+extension String.StringInterpolation {
+    mutating func appendInterpolation<I: BinaryInteger>(
+        _ value: I,
+        radix: Int,
+        width: Int = 0,
+        uppercase: Bool = true
+    ) {
+        var string = String(value, radix: radix, uppercase: uppercase)
+        if width > string.count {
+            string.insert(contentsOf: String(repeating: "0", count: width - string.count), at: string.startIndex)
+        }
+
+        appendLiteral(string)
+    }
+}
+
 private let group = """
 {
   "properties" : {

Sources/MakeColors/Generators/Generator.swift

@@ -1,6 +1,6 @@
 import Foundation
 
-protocol Generator: class {
+protocol Generator: AnyObject {
     static var defaultExtension: String { get }
     static var option: String { get }
 
@@ -9,7 +9,7 @@ protocol Generator: class {
     func generate(data: [String: ColorDef]) throws -> FileWrapper
 }
 
-protocol Context: class {
+protocol Context: AnyObject {
     var prefix: String? { get }
 }
 

Sources/MakeColors/Importers/Figma/FigmaImporter.swift

@@ -0,0 +1,151 @@
+import Foundation
+
+enum FigmaErrors: Error {
+    case invalidUrl
+    case missingToken
+    case invalidResponse
+    case missingColor(String)
+}
+
+class FigmaImporter: Importer {
+    let key: String
+    let token: String
+    let outputName: String
+
+    required init(source: String) throws {
+        // https://www.figma.com/file/:key/:title
+        guard
+            let url = URL(string: source),
+            url.host == "www.figma.com",
+            url.pathComponents.count >= 4,
+            url.pathComponents[1] == "file"
+        else {
+            throw FigmaErrors.invalidUrl
+        }
+
+        key = url.pathComponents[2]
+        outputName = url.pathComponents[3]
+
+        guard let token = ProcessInfo.processInfo.environment["FIGMA_TOKEN"] else {
+            throw FigmaErrors.missingToken
+        }
+
+        self.token = token
+    }
+
+    func read() async throws -> [String: ColorDef] {
+        let styles = try await request(StylesResponse.self, path: "/v1/files/\(key)/styles").meta.styles
+            .filter { $0.styleType == "FILL" }
+
+        let ids = styles.map(\.nodeId).joined(separator: ",")
+
+        let nodes = try await request(
+            NodesResponse.self,
+            path: "/v1/files/\(key)/nodes",
+            query: [URLQueryItem(name: "ids", value: ids)]
+        )
+        .nodes
+
+        var result: [String: ColorDef] = [:]
+        result.reserveCapacity(styles.count)
+
+        for style in styles {
+            guard
+                let node = nodes[style.nodeId],
+                let fill = node.document.fills.first(where: { $0.type == "SOLID" })
+            else {
+                throw FigmaErrors.missingColor(style.name)
+            }
+
+            if node.document.fills.count > 1 {
+                print("Warning: Multiple fills defined for \(style.name)")
+            }
+
+            if fill.blendMode != "NORMAL" {
+                print("Warning: Blend mode \(fill.blendMode) used for \(style.name)")
+            }
+
+            guard !result.keys.contains(style.name) else {
+                throw Errors.duplicateColor(style.name)
+            }
+
+            result[style.name] = .color(Color(fill.color))
+        }
+
+        return result
+    }
+
+    func request<T: Decodable>(_: T.Type = T.self, path: String, query: [URLQueryItem]? = nil) async throws -> T {
+        var components = URLComponents()
+        components.scheme = "https"
+        components.host = "api.figma.com"
+        components.path = path
+        components.queryItems = query
+
+        guard let url = components.url else {
+            fatalError("Cannot create url. Components: \(components)")
+        }
+
+        var request = URLRequest(url: url)
+        request.setValue(token, forHTTPHeaderField: "X-Figma-Token")
+
+        let (data, response) = try await URLSession.shared.data(for: request)
+
+        guard let response = response as? HTTPURLResponse else {
+            fatalError("Non-HTTP-Response received: \(response)")
+        }
+
+        guard response.statusCode == 200 else {
+            throw FigmaErrors.invalidResponse
+        }
+
+        let decoder = JSONDecoder()
+        decoder.keyDecodingStrategy = .convertFromSnakeCase
+        return try decoder.decode(T.self, from: data)
+    }
+}
+
+struct StylesResponse: Decodable {
+    var meta: Meta
+    struct Meta: Decodable {
+        var styles: [Style]
+    }
+
+    struct Style: Decodable {
+        var nodeId: String
+        var styleType: String
+        var name: String
+        var description: String
+    }
+}
+
+struct NodesResponse: Decodable {
+    var nodes: [String: Node]
+
+    struct Node: Decodable {
+        var document: Document
+    }
+
+    struct Document: Decodable {
+        var fills: [Fill]
+    }
+
+    struct Fill: Decodable {
+        var blendMode: String
+        var type: String
+        var color: Color
+    }
+
+    struct Color: Decodable {
+        var r, g, b, a: Float
+    }
+}
+
+extension Color {
+    init(_ color: NodesResponse.Color) {
+        red = UInt8(truncatingIfNeeded: Int(color.r * 0xFF))
+        green = UInt8(truncatingIfNeeded: Int(color.g * 0xFF))
+        blue = UInt8(truncatingIfNeeded: Int(color.b * 0xFF))
+        alpha = UInt8(truncatingIfNeeded: Int(color.a * 0xFF))
+    }
+}

Sources/MakeColors/Importers/Importer.swift

@@ -0,0 +1,15 @@
+protocol Importer {
+    init(source: String) throws
+
+    func read() async throws -> [String: ColorDef]
+
+    var outputName: String { get }
+
+    static var option: String { get }
+}
+
+extension Importer {
+    static var option: String {
+        String(describing: self).droppingSuffix("Importer").lowercased()
+    }
+}

Sources/MakeColors/Importers/List/ListImporter.swift

@@ -0,0 +1,38 @@
+import Foundation
+
+struct ListImporter: Importer {
+    let input: String
+    var outputName: String
+
+    init(source: String) {
+        input = source
+        outputName = URL(fileURLWithPath: source).deletingPathExtension().lastPathComponent
+    }
+
+    func read() throws -> [String: ColorDef] {
+        let scanner = Scanner(string: try readInput())
+        scanner.charactersToBeSkipped = .whitespaces
+
+        return try scanner.colorList()
+    }
+
+    func readInput() throws -> String {
+        if input == "-" {
+            return try readStdin()
+        }
+
+        let url = URL(fileURLWithPath: input)
+        return try String(contentsOf: url)
+    }
+
+    func readStdin() throws -> String {
+        guard
+            let data = try FileHandle.standardInput.readToEnd(),
+            let input = String(data: data, encoding: .utf8)
+        else {
+            throw Errors.cannotReadStdin
+        }
+
+        return input
+    }
+}

Sources/MakeColors/Importers/List/Scanner+ColorParser.swift

@@ -19,11 +19,11 @@ extension Scanner {
             }
         }
 
-        if string("rgba"), string("("), let components = commaSeparated(), components.count == 4, string(")") {
+        if string("rgba"), let components = argumentList(4) {
             return Color(components)
         }
 
-        if string("rgb"), string("("), let components = commaSeparated(), components.count == 3, string(")") {
+        if string("rgb"), let components = argumentList(3) {
             return Color(components)
         }
 
@@ -31,9 +31,58 @@ extension Scanner {
             return Color(white: arguments)
         }
 
+        if string("hsva") {
+            return readHSV(alpha: true)
+        }
+
+        if string("hsv") {
+            return readHSV(alpha: false)
+        }
+
         return nil
     }
 
+    private func readHSV(alpha readAlpha: Bool) -> Color? {
+        guard
+            string("("),
+            let hue = degrees(),
+            string(","),
+            let saturation = component(),
+            string(","),
+            let value = component()
+        else { return nil }
+
+        let alpha: UInt8
+
+        if readAlpha {
+            guard
+                string(","),
+                let value = component()
+            else { return nil }
+            alpha = value
+        } else {
+            alpha = 0xFF
+        }
+
+        guard string(")") else { return nil }
+
+        return Color(hue: hue, saturation: saturation, value: value, alpha: alpha)
+    }
+
+    func degrees() -> Int? {
+        guard let int = scanInt() else { return nil }
+
+        if string("%") {
+            guard 0...100 ~= int else { return nil }
+            return (360 * int) / 100
+        } else if string("°") || string("deg") {
+            return int
+        } else {
+            guard 0...0xFF ~= int else { return nil }
+            return (360 * int) / 0xFF
+        }
+    }
+
     func colorReference() -> String? {
         guard string("@") else { return nil }
         return name()
@@ -61,7 +110,7 @@ extension Scanner {
 
     func colorLine() -> (String, ColorDef)? {
         guard
-            let name = self.name(),
+            let name = name(),
             let def = colorDef(),
             endOfLine()
         else {
@@ -119,13 +168,26 @@ extension Scanner {
     func commaSeparated() -> [UInt8]? {
         var result: [UInt8] = []
         repeat {
-            guard let int = scanInt(), let component = UInt8(exactly: int) else {
+            guard let component = component() else {
                 return nil
             }
             result.append(component)
         } while string(",")
         return result
     }
+
+    func component() -> UInt8? {
+        guard var int = scanInt() else {
+            return nil
+        }
+
+        if string("%") {
+            guard 0...100 ~= int else { return nil }
+            int = int * 0xFF / 100
+        }
+
+        return UInt8(exactly: int)
+    }
 }
 
 private extension Scanner {

Sources/MakeColors/MakeColors.swift

@@ -19,6 +19,39 @@ private struct GeneratorOption: EnumerableFlag, CustomStringConvertible {
     }
 }
 
+private struct ImporterOption: CaseIterable, ExpressibleByArgument, CustomStringConvertible {
+    static let allCases: [ImporterOption] = [
+        .list,
+        .init(type: FigmaImporter.self),
+    ]
+
+    static let list = ImporterOption(type: ListImporter.self)
+
+    let type: Importer.Type
+
+    init(type: Importer.Type) {
+        self.type = type
+    }
+
+    init?(argument: String) {
+        guard
+            let found = Self.allCases
+                .first(where: { $0.description.caseInsensitiveCompare(argument) == .orderedSame })
+        else {
+            return nil
+        }
+        self = found
+    }
+
+    var description: String {
+        type.option
+    }
+
+    static func == (lhs: ImporterOption, rhs: ImporterOption) -> Bool {
+        lhs.type == rhs.type
+    }
+}
+
 enum Errors: Error {
     case syntaxError
     case duplicateColor(String)
@@ -47,13 +80,17 @@ enum HelpTexts {
     )
 }
 
-public final class MakeColors: ParsableCommand, Context {
+@main
+public final class MakeColors: AsyncParsableCommand, Context {
     @Argument(help: HelpTexts.input)
     var input: String
 
     @Flag(help: "The formatter to use.")
     private var formatter = GeneratorOption.allCases[0]
 
+    @Option(help: "The importer to use.")
+    private var importer = ImporterOption.list
+
     @Option(help: "Prefix for color names.")
     var prefix: String?
 
@@ -65,11 +102,9 @@ public final class MakeColors: ParsableCommand, Context {
 
     public init() {}
 
-    public func run() throws {
-        let scanner = Scanner(string: try readInput())
-        scanner.charactersToBeSkipped = .whitespaces
-
-        let data = try scanner.colorList()
+    public func run() async throws {
+        let importer = try importer.type.init(source: input)
+        let data = try await importer.read()
 
         if dump {
             try dump(data: data)
@@ -78,27 +113,7 @@ public final class MakeColors: ParsableCommand, Context {
         let generator = formatter.type.init(context: self)
         let fileWrapper = try generator.generate(data: data)
 
-        try writeOutput(fileWrapper)
-    }
-
-    func readInput() throws -> String {
-        if input == "-" {
-            return try readStdin()
-        }
-
-        let url = URL(fileURLWithPath: input)
-        return try String(contentsOf: url)
-    }
-
-    func readStdin() throws -> String {
-        guard
-            let data = try FileHandle.standardInput.readToEnd(),
-            let input = String(data: data, encoding: .utf8)
-        else {
-            throw Errors.cannotReadStdin
-        }
-
-        return input
+        try writeOutput(fileWrapper, name: output ?? "\(importer.outputName).\(formatter.type.defaultExtension)")
     }
 
     func dump(data: [String: ColorDef]) throws {
@@ -118,7 +133,7 @@ public final class MakeColors: ParsableCommand, Context {
         }
     }
 
-    func writeOutput(_ wrapper: FileWrapper) throws {
+    func writeOutput(_ wrapper: FileWrapper, name: String) throws {
         if shouldWriteToStdout {
             guard wrapper.isRegularFile, let contents = wrapper.regularFileContents else {
                 throw Errors.cannotWriteWrapperToStdout
@@ -126,19 +141,10 @@ public final class MakeColors: ParsableCommand, Context {
 
             FileHandle.standardOutput.write(contents)
         } else {
-            let writeURL = outputURL(extension: formatter.type.defaultExtension)
+            let writeURL = URL(fileURLWithPath: name)
             try wrapper.write(to: writeURL, options: .atomic, originalContentsURL: nil)
         }
     }
 
     var shouldWriteToStdout: Bool { output == "-" || (input == "-" && output == nil) }
-
-    func outputURL(extension: String) -> URL {
-        if let output = output {
-            return URL(fileURLWithPath: output)
-        } else {
-            let basename = URL(fileURLWithPath: input).deletingPathExtension().lastPathComponent
-            return URL(fileURLWithPath: basename).appendingPathExtension(`extension`)
-        }
-    }
 }

Sources/MakeColors/Model/Color+HSV.swift

@@ -0,0 +1,45 @@
+extension Color {
+    init(hue: Int, saturation: UInt8, value: UInt8, alpha: UInt8 = 0xFF) {
+        let degrees = abs(hue % 360)
+
+        let saturation = Double(saturation) / 0xFF
+        let value = Double(value) / 0xFF
+
+        // swiftlint:disable identifier_name - Wish I knew what these actually mean.
+        let C = saturation * value
+        let X = C * (1 - abs((Double(degrees) / 60).truncatingRemainder(dividingBy: 2) - 1))
+        let m = value - C
+        // swiftlint:enable identifier_name
+
+        let result: (r: Double, g: Double, b: Double)
+        switch degrees {
+        case 0..<60:
+            result = (C, X, 0)
+
+        case 60..<120:
+            result = (X, C, 0)
+
+        case 120..<180:
+            result = (0, C, X)
+
+        case 180..<240:
+            result = (0, X, C)
+
+        case 240..<300:
+            result = (X, 0, C)
+
+        case 300..<360:
+            result = (C, 0, X)
+
+        default:
+            fatalError("Degrees out of range")
+        }
+
+        self.init(
+            red: UInt8(((result.r + m) * 0xFF).rounded()),
+            green: UInt8(((result.g + m) * 0xFF).rounded()),
+            blue: UInt8(((result.b + m) * 0xFF).rounded()),
+            alpha: alpha
+        )
+    }
+}

Sources/MakeColors/main.swift

@@ -1,3 +0,0 @@
-import LibMakeColors
-
-MakeColors.main()

Tests/MakeColorsTests/AssetCatalogFormattingTest.swift

@@ -0,0 +1,26 @@
+@testable import MakeColors
+import RBBJSON
+import XCTest
+
+class AssetCatalogFormattingTest: XCTestCase {
+    func testColorProducedValidJSON() throws {
+        let color = Color(red: 0xFF, green: 0xF0, blue: 0x0F)
+        let data = Data(color.json().utf8)
+
+        let json = try JSONDecoder().decode(RBBJSON.self, from: data)
+
+        XCTAssertEqual(json.info.author, .string("de.5sw.MakeColors"))
+        XCTAssertEqual(json.info.version, .number(1))
+
+        XCTAssertEqual(Array(json.colors[any: .child]).count, 1)
+
+        XCTAssertEqual(json.colors[0].idiom, .string("universal"))
+
+        let jsonColor = json.colors[0].color
+        XCTAssertEqual(jsonColor["color-space"], .string("srgb"))
+        XCTAssertEqual(jsonColor.components.alpha, .string("1.0"))
+        XCTAssertEqual(jsonColor.components.red, .string("0xFF"))
+        XCTAssertEqual(jsonColor.components.green, .string("0xF0"))
+        XCTAssertEqual(jsonColor.components.blue, .string("0x0F"))
+    }
+}

Tests/MakeColorsTests/ColorHSVTest.swift

@@ -0,0 +1,39 @@
+@testable import MakeColors
+import XCTest
+
+final class ColorHSVTest: XCTestCase {
+    func testHSV0Degrees() {
+        let color = Color(hue: 0, saturation: 0xFF, value: 0xFF)
+        XCTAssertEqual(color, Color(red: 0xFF, green: 0, blue: 0))
+    }
+
+    func testHSV60Degrees() {
+        let color = Color(hue: 60, saturation: 0xFF, value: 0xFF)
+        XCTAssertEqual(color, Color(red: 0xFF, green: 0xFF, blue: 0))
+    }
+
+    func testHSV120Degrees() {
+        let color = Color(hue: 120, saturation: 0xFF, value: 0xFF)
+        XCTAssertEqual(color, Color(red: 0, green: 0xFF, blue: 0))
+    }
+
+    func testHSV180Degrees() {
+        let color = Color(hue: 180, saturation: 0xFF, value: 0xFF)
+        XCTAssertEqual(color, Color(red: 0, green: 0xFF, blue: 0xFF))
+    }
+
+    func testHSV240Degrees() {
+        let color = Color(hue: 240, saturation: 0xFF, value: 0xFF)
+        XCTAssertEqual(color, Color(red: 0, green: 0, blue: 0xFF))
+    }
+
+    func testHSV300Degrees() {
+        let color = Color(hue: 300, saturation: 0xFF, value: 0xFF)
+        XCTAssertEqual(color, Color(red: 0xFF, green: 0, blue: 0xFF))
+    }
+
+    func testHSV360Degrees() {
+        let color = Color(hue: 360, saturation: 0xFF, value: 0xFF)
+        XCTAssertEqual(color, Color(red: 0xFF, green: 0, blue: 0))
+    }
+}

Tests/MakeColorsTests/ColorParserTest.swift

@@ -1,4 +1,4 @@
-@testable import LibMakeColors
+@testable import MakeColors
 import XCTest
 
 final class ColorParserTest: XCTestCase {
@@ -57,8 +57,67 @@ final class ColorParserTest: XCTestCase {
         XCTAssertNil(color)
     }
 
+    func testScanningColorWithPercentage() throws {
+        let color = scanColor("rgba(100%, 0, 50%, 100%)")
+        XCTAssertEqual(color, Color(red: 255, green: 0, blue: 127, alpha: 255))
+    }
+
+    func testReadingComponentAsByte() throws {
+        let scanner = Scanner(string: "128")
+        XCTAssertEqual(scanner.component(), 128)
+        XCTAssertTrue(scanner.isAtEnd)
+    }
+
+    func testReadingComponentAs100Percent() throws {
+        let scanner = Scanner(string: "100%")
+        XCTAssertEqual(scanner.component(), 0xFF)
+        XCTAssertTrue(scanner.isAtEnd)
+    }
+
+    func testReadingComponentAs0Percent() throws {
+        let scanner = Scanner(string: "0%")
+        XCTAssertEqual(scanner.component(), 0)
+        XCTAssertTrue(scanner.isAtEnd)
+    }
+
+    func testReadingComponentAs50PercentRoundsDown() throws {
+        let scanner = Scanner(string: "50%")
+        XCTAssertEqual(scanner.component(), 127)
+        XCTAssertTrue(scanner.isAtEnd)
+    }
+
+    func testScanningDegreesAsByte() throws {
+        let scanner = Scanner(string: "128")
+        XCTAssertEqual(scanner.degrees(), 180)
+    }
+
+    func testScanningDegreesAsPercentage() throws {
+        let scanner = Scanner(string: "50%")
+        XCTAssertEqual(scanner.degrees(), 180)
+    }
+
+    func testScanningDegrees() throws {
+        let scanner = Scanner(string: "120°")
+        XCTAssertEqual(scanner.degrees(), 120)
+    }
+
+    func testScanningDegreesWithDegSuffix() throws {
+        let scanner = Scanner(string: "120 deg")
+        XCTAssertEqual(scanner.degrees(), 120)
+    }
+
+    func testScanningHSVColor() throws {
+        XCTAssertEqual(scanColor("hsv(60°, 255, 100%)"), Color(red: 0xFF, green: 0xFF, blue: 0))
+    }
+
+    func testScanningHSVAColor() throws {
+        XCTAssertEqual(scanColor("hsva(60°, 50%, 255, 99)"), Color(red: 0xFF, green: 0xFF, blue: 128, alpha: 99))
+    }
+
     private func scanColor(_ input: String) -> Color? {
         let scanner = Scanner(string: input)
-        return scanner.color()
+        let result = scanner.color()
+        XCTAssertTrue(result == nil || scanner.isAtEnd)
+        return result
     }
 }