Removed sealed keywords from ColumnIndex and ColunmName attributes (#76)

* Removed sealed keywords from ColumnIndex and ColunmName attributes

* Update nuget version

* Encapsulated attribute properties

* Unit tests added

* Argument validation fix

src/ExcelColumnIndexAttribute.cs

@@ -10,25 +10,39 @@ namespace ExcelMapper
     /// Specifies the column index that is used when deserializing a property
     /// </summary>
     [AttributeUsage(AttributeTargets.Property | AttributeTargets.Field, AllowMultiple = false)]
-    public sealed class ExcelColumnIndexAttribute : Attribute
+    public class ExcelColumnIndexAttribute : Attribute
     {
+        private int _index;
+
         /// <summary>
         /// Initializes a new instance of <see cref="ExcelColumnIndexAttribute"/> with the specified column index.
         /// </summary>
         /// <param name="index">The index of the column.</param>
         public ExcelColumnIndexAttribute(int index)
         {
-            if (index < 0)
-            {
-                throw new ArgumentOutOfRangeException(nameof(index), index, $"Column index {index} must be greater or equal to zero.");
-            }
-
+            CheckIndexGreaterOrEqualToZero(index, nameof(index));
             Index = index;
         }
 
         /// <summary>
         /// The index of the column.
         /// </summary>
-        public int Index { get; }
+        public int Index
+        {
+            get => _index;
+            set
+            {
+                CheckIndexGreaterOrEqualToZero(value, nameof(value));
+                _index = value;
+            }
+        }
+
+        private void CheckIndexGreaterOrEqualToZero(int index, string paramName)
+        {
+            if (index < 0)
+            {
+                throw new ArgumentOutOfRangeException(paramName, index, $"Column index {index} must be greater or equal to zero.");
+            }
+        }
     }
 }

src/ExcelColumnNameAttribute.cs

@@ -10,30 +10,44 @@ namespace ExcelMapper
     /// Specifies the column name that is used when deserializing a property
     /// </summary>
     [AttributeUsage(AttributeTargets.Property | AttributeTargets.Field, AllowMultiple = false)]
-    public sealed class ExcelColumnNameAttribute : Attribute
+    public class ExcelColumnNameAttribute : Attribute
     {
+        private string _name;
+
         /// <summary>
         /// Initializes a new instance of <see cref="ExcelColumnNameAttribute"/> with the specified column name.
         /// </summary>
         /// <param name="name">The name of the column.</param>
         public ExcelColumnNameAttribute(string name)
+        {
+            CheckNameNullOrEmpty(name , nameof(name));
+            Name = name;
+        }
+
+        /// <summary>
+        /// The name of the column.
+        /// </summary>
+        public string Name
+        {
+            get => _name;
+            set
+            {
+                CheckNameNullOrEmpty(value , nameof(value));
+                _name = value;
+            }
+        }
+
+        private void CheckNameNullOrEmpty(string name, string paramName)
         {
             if (name == null)
             {
-                throw new ArgumentNullException(nameof(name));
+                throw new ArgumentNullException(paramName);
             }
 
             if (name.Length == 0)
             {
-                throw new ArgumentException("Column name cannot be empty.", nameof(name));
+                throw new ArgumentException("Column name cannot be empty.", paramName);
             }
-
-            Name = name;
         }
-
-        /// <summary>
-        /// The name of the column.
-        /// </summary>
-        public string Name { get; }
     }
 }

src/ExcelMapper.csproj

@@ -7,7 +7,7 @@
 
   <PropertyGroup>
     <PackageId>ExcelDataReader.Mapping</PackageId>
-    <PackageVersion>2.2.1</PackageVersion>
+    <PackageVersion>2.2.2</PackageVersion>
     <Authors>Hugh Bellamy</Authors>
     <Title>Excel Mapping Helper</Title>
     <Description>An extension of ExcelDataReader that supports fluent mapping of rows to C# objects.</Description>

tests/ExcelMapper/ExcelColumnIndexAttributeTests.cs

@@ -19,5 +19,24 @@ public void Ctor_InvalidIndex_ThrowsArgumentOutOfRangeException()
         {
             Assert.Throws<ArgumentOutOfRangeException>("index", () => new ExcelColumnIndexAttribute(-1));
         }
+
+        [Theory]
+        [InlineData(0)]
+        [InlineData(1)]
+        public void Index_Set_GetReturnsExpectedInt(int index)
+        {
+            var attribute = new ExcelColumnIndexAttribute(10)
+            {
+                Index = index
+            };
+            Assert.Equal(index, attribute.Index);
+        }
+
+        [Fact]
+        public void Index_Set_GetInvalidIndex_ThrowsArgumentOutOfRangeException()
+        {
+            var attribute = new ExcelColumnIndexAttribute(1);
+            Assert.Throws<ArgumentOutOfRangeException>("value", () => attribute.Index = -1);
+        }
     }
 }

tests/ExcelMapper/ExcelColumnNameAttributeTests.cs

@@ -25,5 +25,31 @@ public void Ctor_EmptyName_ThrowsArgumentNullException()
         {
             Assert.Throws<ArgumentException>("name", () => new ExcelColumnNameAttribute(string.Empty));
         }
+
+        [Theory]
+        [InlineData("columnname")]
+        [InlineData("ColumnName")]
+        public void Name_Set_GetReturnsExpected(string value)
+        {
+            var attribute = new ExcelColumnNameAttribute("Name")
+            {
+                Name = value
+            };
+            Assert.Equal(value, attribute.Name);
+        }
+
+        [Fact]
+        public void Name_SetNull_ThrowsArgumentNullException()
+        {
+            var attribute = new ExcelColumnNameAttribute("Name");
+            Assert.Throws<ArgumentNullException>("value", () => attribute.Name = null);
+        }
+
+        [Fact]
+        public void Name_SetEmpty_ThrowsArgumentNullException()
+        {
+            var attribute = new ExcelColumnNameAttribute("Name");
+            Assert.Throws<ArgumentException>("value", () => attribute.Name = string.Empty);
+        }
     }
 }