Implemented the comparable contract for the primitive value object. (#14

)
fluxera · May 28, 2022 · df6ad76 · df6ad76
1 parent 6f377be
commit df6ad76
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Showing 3 changed files with 34 additions and 7 deletions.
diff --git a/src/Fluxera.ValueObject/PrimitiveValueObject.cs b/src/Fluxera.ValueObject/PrimitiveValueObject.cs
@@ -18,8 +18,9 @@
 	/// <typeparam name="TValueObject">The type of the value object.</typeparam>
 	/// <typeparam name="TValue">The type of the value.</typeparam>
 	[PublicAPI]
-	public abstract class PrimitiveValueObject<TValueObject, TValue> : ValueObject<TValueObject>
-		where TValueObject : ValueObject<TValueObject>
+	public abstract class PrimitiveValueObject<TValueObject, TValue> : ValueObject<TValueObject>, IComparable<PrimitiveValueObject<TValueObject, TValue>>
+		where TValueObject : PrimitiveValueObject<TValueObject, TValue>
+		where TValue : IComparable
 	{
 		static PrimitiveValueObject()
 		{
@@ -43,6 +44,19 @@ protected PrimitiveValueObject(TValue value)
 		/// </summary>
 		public TValue Value { get; private set; }
 
+
+		/// <inheritdoc />
+		public int CompareTo(PrimitiveValueObject<TValueObject, TValue> other)
+		{
+			return (this.Value, other.Value) switch
+			{
+				(null, null) => 0,
+				(null, _) => -1,
+				(_, null) => 1,
+				(_, _) => this.Value.CompareTo(other.Value)
+			};
+		}
+
 		/// <inheritdoc />
 		protected sealed override IEnumerable<object> GetEqualityComponents()
 		{

diff --git a/src/Fluxera.ValueObject/ValueObject.cs b/src/Fluxera.ValueObject/ValueObject.cs
@@ -1,5 +1,6 @@
 namespace Fluxera.ValueObject
 {
+	using System;
 	using System.Collections.Generic;
 	using System.Linq;
 	using System.Text;
@@ -10,7 +11,7 @@
 	/// </summary>
 	/// <typeparam name="TValueObject">The type of the value object.</typeparam>
 	[PublicAPI]
-	public abstract class ValueObject<TValueObject>
+	public abstract class ValueObject<TValueObject> : IEquatable<TValueObject>
 		where TValueObject : ValueObject<TValueObject>
 	{
 		/// <summary>
@@ -22,6 +23,12 @@ public abstract class ValueObject<TValueObject>
 		/// </remarks>
 		private const int HashMultiplier = 37;
 
+		/// <inheritdoc />
+		public bool Equals(TValueObject other)
+		{
+			return this.Equals(other as object);
+		}
+
 		/// <summary>
 		///     Checks if the given value objects are equal.
 		/// </summary>
@@ -69,7 +76,7 @@ public sealed override int GetHashCode()
 			{
 				// It is possible for two objects to return the same hash code based on
 				// identically valued properties, even if they are of different types,
-				// so we include the value object type in the hash calculation
+				// so we include the value object type in the hash calculation.
 				int hashCode = this.GetType().GetHashCode();
 
 				foreach(object component in this.GetEqualityComponents())

diff --git a/tests/Fluxera.ValueObject.UnitTests/Model/Address.cs b/tests/Fluxera.ValueObject.UnitTests/Model/Address.cs
@@ -1,11 +1,11 @@
 namespace Fluxera.ValueObject.UnitTests.Model
 {
-	using System.Threading.Channels;
-	using Guards;
+	using System;
+	using Fluxera.Guards;
 	using JetBrains.Annotations;
 
 	[PublicAPI]
-	public class Address : ValueObject<Address>
+	public class Address : ValueObject<Address>, IComparable
 	{
 		public Address(string street, string houseNumber, string postCode, string city)
 		{
@@ -27,5 +27,11 @@ public Address(string street, string houseNumber, string postCode, string city)
 		public string PostCode { get; }
 
 		public string City { get; }
+
+		/// <inheritdoc />
+		public int CompareTo(object? obj)
+		{
+			return string.Compare(this.PostCode, obj as string, StringComparison.Ordinal);
+		}
 	}
 }