Color Picker: Validate uniqueness of selected colors (#20431)

* Added unique color checker to color picker.

* Added Unittest for duplicates

* optimized for codescene

* removed the bump and simplified the function

* Fixed behaviour for duplicate checks so unit test passes.
A little refactoring.

* Adds continue so invalid colors aren't checked for duplicates.

---------

Co-authored-by: Andy Butland <abutland73@gmail.com>

src/Umbraco.Infrastructure/PropertyEditors/ColorPickerConfigurationEditor.cs

@@ -10,8 +10,11 @@ using Umbraco.Extensions;
 
 namespace Umbraco.Cms.Core.PropertyEditors;
 
-internal sealed class ColorPickerConfigurationEditor : ConfigurationEditor<ColorPickerConfiguration>
+internal sealed partial class ColorPickerConfigurationEditor : ConfigurationEditor<ColorPickerConfiguration>
 {
+    /// <summary>
+    /// Initializes a new instance of the <see cref="ColorPickerConfigurationEditor"/> class.
+    /// </summary>
     public ColorPickerConfigurationEditor(IIOHelper ioHelper, IConfigurationEditorJsonSerializer configurationEditorJsonSerializer)
         : base(ioHelper)
     {
@@ -19,13 +22,17 @@ internal sealed class ColorPickerConfigurationEditor : ConfigurationEditor<Color
         items.Validators.Add(new ColorListValidator(configurationEditorJsonSerializer));
     }
 
-    internal sealed class ColorListValidator : IValueValidator
+    internal sealed partial class ColorListValidator : IValueValidator
     {
         private readonly IConfigurationEditorJsonSerializer _configurationEditorJsonSerializer;
 
+        /// <summary>
+        /// Initializes a new instance of the <see cref="ColorListValidator"/> class.
+        /// </summary>
         public ColorListValidator(IConfigurationEditorJsonSerializer configurationEditorJsonSerializer)
             => _configurationEditorJsonSerializer = configurationEditorJsonSerializer;
 
+        /// <inheritdoc/>
         public IEnumerable<ValidationResult> Validate(object? value, string? valueType, object? dataTypeConfiguration, PropertyValidationContext validationContext)
         {
             var stringValue = value?.ToString();
@@ -46,17 +53,53 @@ internal sealed class ColorPickerConfigurationEditor : ConfigurationEditor<Color
 
             if (items is null)
             {
-                yield return new ValidationResult($"The configuration value {stringValue} is not a valid color picker configuration", new[] { "items" });
+                yield return new ValidationResult($"The configuration value {stringValue} is not a valid color picker configuration", ["items"]);
                 yield break;
             }
 
+            var seen = new HashSet<string>(StringComparer.OrdinalIgnoreCase);
+            var duplicates = new List<string>();
             foreach (ColorPickerConfiguration.ColorPickerItem item in items)
             {
-                if (Regex.IsMatch(item.Value, "^([0-9a-f]{3}|[0-9a-f]{6})$", RegexOptions.IgnoreCase) == false)
+                if (ColorPattern().IsMatch(item.Value) == false)
                 {
-                    yield return new ValidationResult($"The value {item.Value} is not a valid hex color", new[] { "items" });
+                    yield return new ValidationResult($"The value {item.Value} is not a valid hex color", ["items"]);
+                    continue;
+                }
+
+                var normalized = Normalize(item.Value);
+                if (seen.Add(normalized) is false)
+                {
+                    duplicates.Add(normalized);
                 }
             }
+
+            if (duplicates.Count > 0)
+            {
+                yield return new ValidationResult(
+                    $"Duplicate color values are not allowed: {string.Join(", ", duplicates)}",
+                    ["items"]);
+            }
         }
+
+        private static string Normalize(string? value)
+        {
+            if (string.IsNullOrWhiteSpace(value))
+            {
+                return string.Empty;
+            }
+
+            var normalizedValue = value.Trim().ToLowerInvariant();
+
+            if (normalizedValue.Length == 3)
+            {
+                normalizedValue = $"{normalizedValue[0]}{normalizedValue[0]}{normalizedValue[1]}{normalizedValue[1]}{normalizedValue[2]}{normalizedValue[2]}";
+            }
+
+            return normalizedValue;
+        }
+
+        [GeneratedRegex("^([0-9a-f]{3}|[0-9a-f]{6})$", RegexOptions.IgnoreCase, "en-GB")]
+        private static partial Regex ColorPattern();
     }
 }

tests/Umbraco.Tests.UnitTests/Umbraco.Core/PropertyEditors/ColorListValidatorTest.cs

@@ -58,4 +58,24 @@ public class ColorListValidatorTest
                 PropertyValidationContext.Empty());
         Assert.AreEqual(2, result.Count());
     }
+
+    [Test]
+    public void Validates_Color_Vals_Are_Unique()
+    {
+        var validator = new ColorPickerConfigurationEditor.ColorListValidator(ConfigurationEditorJsonSerializer());
+        var result =
+            validator.Validate(
+                new JsonArray(
+                    JsonNode.Parse("""{"value": "FFFFFF", "label": "One"}"""),
+                    JsonNode.Parse("""{"value": "000000", "label": "Two"}"""),
+                    JsonNode.Parse("""{"value": "FF00AA", "label": "Three"}"""),
+                    JsonNode.Parse("""{"value": "fff", "label": "Four"}"""),
+                    JsonNode.Parse("""{"value": "000000", "label": "Five"}"""),
+                    JsonNode.Parse("""{"value": "F0A", "label": "Six"}""")),
+                null,
+                null,
+                PropertyValidationContext.Empty());
+        Assert.AreEqual(1, result.Count());
+        Assert.IsTrue(result.First().ErrorMessage.Contains("ffffff, 000000, ff00aa"));
+    }
 }