TextBox: Data-type validation for max chars (fixes #18817) (#20843)

* configure max chars for textbox

* min 1

* Adds server-side check for text box min and max character validation.

* Applied suggestion from code review.

* Bumped version of test helper

* Fixed test that was creating a text string data type with too large a maximum characters setting.

---------

Co-authored-by: Andy Butland <abutland73@gmail.com>
Co-authored-by: Nhu Dinh <hnd@umbraco.dk>

tests/Umbraco.Tests.UnitTests/Umbraco.Core/PropertyEditors/Validators/IntegerValidatorTests.cs

@@ -0,0 +1,74 @@
+// Copyright (c) Umbraco.
+// See LICENSE for more details.
+
+using NUnit.Framework;
+using Umbraco.Cms.Core.Models.Validation;
+using Umbraco.Cms.Core.PropertyEditors;
+using Umbraco.Cms.Core.PropertyEditors.Validators;
+
+namespace Umbraco.Cms.Tests.UnitTests.Umbraco.Core.PropertyEditors.Validators;
+
+[TestFixture]
+public class IntegerValidatorTests
+{
+    [TestCase(null, true)]
+    [TestCase("", true)]
+    [TestCase(" ", false)]
+    [TestCase("x", false)]
+    [TestCase("99", true)]
+    public void Validates_Integer(object? value, bool expectedSuccess)
+    {
+        var validator = CreateValidator();
+        var result = validator.Validate(value, ValueTypes.Integer, null, PropertyValidationContext.Empty());
+        if (expectedSuccess)
+        {
+            Assert.IsEmpty(result);
+        }
+        else
+        {
+            Assert.AreEqual(1, result.Count());
+
+            var validationResult = result.First();
+            Assert.IsTrue(validationResult.ErrorMessage.Contains("is not a valid integer"));
+        }
+    }
+
+    public enum RangeResult
+    {
+        Success,
+        BelowMin,
+        AboveMax,
+    }
+
+    [TestCase("5", RangeResult.BelowMin)]
+    [TestCase("10", RangeResult.Success)]
+    [TestCase("15", RangeResult.Success)]
+    [TestCase("20", RangeResult.Success)]
+    [TestCase("25", RangeResult.AboveMax)]
+    public void Validates_Integer_Within_Range(object? value, RangeResult expectedResult)
+    {
+        var validator = CreateValidator(10, 20);
+        var result = validator.Validate(value, ValueTypes.Integer, null, PropertyValidationContext.Empty());
+        if (expectedResult == RangeResult.Success)
+        {
+            Assert.IsEmpty(result);
+        }
+        else
+        {
+            Assert.AreEqual(1, result.Count());
+
+            var validationResult = result.First();
+            if (expectedResult == RangeResult.BelowMin)
+            {
+                Assert.IsTrue(validationResult.ErrorMessage.Contains("less than the minimum allowed value"));
+            }
+            else if (expectedResult == RangeResult.AboveMax)
+            {
+                Assert.IsTrue(validationResult.ErrorMessage.Contains("greater than the maximum allowed value"));
+            }
+        }
+    }
+
+    private static IntegerValidator CreateValidator(int? min = null, int? max = null) =>
+        min.HasValue is false && max.HasValue is false ? new IntegerValidator() : new IntegerValidator(min, max);
+}