[Issue-46] Clamp sRGB display values

Sources/YCoreUI/Extensions/UIKit/UIColor+rgbValue.swift

@@ -15,14 +15,36 @@ public extension UIColor {
     ///   - isUppercase: whether the hex values should be upper or lower case
     /// - Returns: the formatted hexadecimal string
     func rgbDisplayString(prefix: String? = nil, isUppercase: Bool = true) -> String {
+        _rgbDisplayString(prefix: prefix, isUppercase: isUppercase, isDebug: false)
+    }
+
+    /// Formats a color as an RGB hexadecimal string. Appropriate for debug printing.
+    /// - Parameters:
+    ///   - prefix: optional prefix to precede the hexadecimal value such as `0x` or `#` (default = nil)
+    ///   - isUppercase: whether the hex values should be upper or lower case
+    /// - Returns: the formatted hexadecimal string (with an `⚠️` for colors that fall outside of the sRGB color space)
+    func rgbDebugDisplayString(prefix: String? = nil, isUppercase: Bool = true) -> String {
+        _rgbDisplayString(prefix: prefix, isUppercase: isUppercase, isDebug: true)
+    }
+
+    private func _rgbDisplayString(prefix: String?, isUppercase: Bool, isDebug: Bool) -> String {
         let comp = rgbaComponents
         let format = isUppercase ? "%02X%02X%02X" : "%02x%02x%02x"
+        let r = Int(round(comp.red * 255))
+        let g = Int(round(comp.green * 255))
+        let b = Int(round(comp.blue * 255))
+        let isRGB = (r >= 0 && r <= 255) && (g >= 0 && g <= 255) && (b >= 0 && b <= 255)
+        let prefix = prefix ?? ""
         let value = String(
             format: format,
-            Int(round(comp.red * 255)),
-            Int(round(comp.green * 255)),
-            Int(round(comp.blue * 255))
+            min(max(r, 0), 255),
+            min(max(g, 0), 255),
+            min(max(b, 0), 255)
         )
-        return "\(prefix ?? "")\(value)"
+        let suffix = (isDebug && !isRGB) ? "⚠️" : ""
+        if !isRGB && YCoreUI.isLoggingEnabled {
+            YCoreUI.colorLogger.warning("Color \(self) falls outside of the sRGB color space.")
+        }
+        return "\(prefix)\(value)\(suffix)"
     }
 }

Sources/YCoreUI/YCoreUI+Logging.swift

@@ -18,4 +18,6 @@ public struct YCoreUI {
 internal extension YCoreUI {
     /// Logger for warnings related to image loading. cf. `ImageAsset` and `SystemImage`
     static let imageLogger = Logger(subsystem: "YCoreUI", category: "images")
+    /// Logger for warnings related to colors. cf `UIColor+rgbValue.swift`
+    static let colorLogger = Logger(subsystem: "YCoreUI", category: "colors")
 }

Tests/YCoreUITests/Extensions/UIKit/UIColor+rgbValueTests.swift

@@ -7,6 +7,7 @@
 //
 
 import XCTest
+@testable import YCoreUI
 
 // Large tuples help us build unit test expectations concisely
 // swiftlint:disable large_tuple
@@ -42,4 +43,35 @@ final class UIColorRgbValueTests: XCTestCase {
         // We exect each rgb color channel value to be rounded appropriately
         XCTAssertEqual(color.rgbDisplayString(), "80BFA6")
     }
+
+    func testSuffixes() {
+        testCases.forEach {
+            XCTAssertFalse($0.color.rgbDisplayString().hasSuffix("⚠️"))
+            XCTAssertFalse($0.color.rgbDebugDisplayString().hasSuffix("⚠️"))
+            XCTAssertEqual($0.color.rgbDisplayString(), $0.color.rgbDebugDisplayString())
+        }
+
+        let p3Colors = [
+            UIColor(displayP3Red: 1, green: 0, blue: 0, alpha: 1),
+            UIColor(displayP3Red: 0, green: 1, blue: 0, alpha: 1),
+            UIColor(displayP3Red: 0, green: 0, blue: 1, alpha: 1),
+            UIColor(displayP3Red: 1, green: 1, blue: 0, alpha: 1),
+            UIColor(displayP3Red: 1, green: 0, blue: 1, alpha: 1),
+            UIColor(displayP3Red: 0, green: 1, blue: 1, alpha: 1),
+            UIColor(red: 1.25, green: 0, blue: 0, alpha: 1),
+            UIColor(red: 0, green: 1.25, blue: 0, alpha: 1),
+            UIColor(red: 0, green: 0, blue: 1.25, alpha: 1),
+            UIColor(red: -0.25, green: 0, blue: 0, alpha: 1),
+            UIColor(red: 0, green: -0.25, blue: 0, alpha: 1),
+            UIColor(red: 0, green: 0, blue: -0.25, alpha: 1)
+        ]
+
+        p3Colors.forEach {
+            XCTAssertFalse($0.rgbDisplayString().hasSuffix("⚠️"))
+            XCTAssertTrue($0.rgbDebugDisplayString().hasSuffix("⚠️"))
+            YCoreUI.isLoggingEnabled = false
+        }
+
+        YCoreUI.isLoggingEnabled = true
+    }
 }