Added unit tests for CategoryName value object

server/tests/Questeloper.Tests.Unit/DomainTests/ValueObjects/CategoryNameTests.cs

@@ -0,0 +1,87 @@
+using FluentAssertions;
+using Questeloper.Domain.Exceptions;
+using Questeloper.Domain.ValueObjects;
+
+namespace Questeloper.Tests.Unit.DomainTests.ValueObjects;
+
+public class CategoryNameTests
+{
+    [Fact]
+    public void Constructor_WhenValueIsNull_ShouldThrowValueIsEmptyException()
+    {
+        // Act
+        var act = () => new CategoryName(null);
+
+        // Assert
+        act.Should().Throw<ValueIsEmptyException>();
+    }
+
+    [Fact]
+    public void Constructor_WhenValueIsWhitespace_ShouldThrowValueIsEmptyException()
+    {
+        // Act
+        var act = () => new CategoryName(" ");
+
+        // Assert
+        act.Should().Throw<ValueIsEmptyException>();
+    }
+
+    [Theory]
+    [InlineData("abc")]
+    public void Constructor_ForValidValue_ShouldNotThrow(string validValue)
+    {
+        // Act
+        var act = () => new CategoryName(validValue);
+
+        // Assert
+        act.Should().NotThrow();
+    }
+
+    [Theory]
+    [InlineData("ab")]
+    public void Constructor_WhenValueIsIncorrectLength_ShouldThrowValueIncorrectLengthException(string invalidValue)
+    {
+        // Act
+        Action act = () => new CategoryName(invalidValue);
+
+        // Assert
+        act.Should().Throw<ValueIncorrectLengthException>();
+    }
+
+    [Fact]
+    public void ImplicitConversion_ToString_ShouldReturnCorrectStringValue()
+    {
+        // Arrange
+        var categoryName = new CategoryName("Programming");
+
+        // Act
+        string result = categoryName;
+
+        // Assert
+        result.Should().Be("Programming");
+    }
+
+    [Fact]
+    public void ExplicitConversion_FromString_ShouldCreateValidObject()
+    {
+        // Act
+        var categoryName = (CategoryName)"Design";
+
+        // Assert
+        categoryName.Should().NotBeNull();
+        categoryName.Value.Should().Be("Design");
+    }
+
+    [Fact]
+    public void ToString_Invoked_ShouldReturnCorrectValue()
+    {
+        // Arrange
+        var categoryName = new CategoryName("Art");
+
+        // Act
+        var result = categoryName.ToString();
+
+        // Assert
+        result.Should().Be("Art");
+    }
+}