DDD improvements

CSharpFunctionalExtensions/AggregateRoot.cs

@@ -0,0 +1,20 @@
+using System.Collections.Generic;
+
+namespace CSharpFunctionalExtensions
+{
+    public abstract class AggregateRoot<TId, TDomainEvent> : Entity<TId>, IAggregateRoot<TDomainEvent>
+    {
+        private readonly List<TDomainEvent> _domainEvents = new List<TDomainEvent>();
+        public virtual IEnumerable<TDomainEvent> DomainEvents => _domainEvents;
+
+        protected virtual void Raise(TDomainEvent newEvent)
+        {
+            _domainEvents.Add(newEvent);
+        }
+
+        protected virtual void ClearEvents()
+        {
+            _domainEvents.Clear();
+        }
+    }
+}

CSharpFunctionalExtensions/Entity/Entity.cs

@@ -1,6 +1,6 @@
 namespace CSharpFunctionalExtensions
 {
-    public abstract class Entity<TId>
+    public abstract class Entity<TId> : IEntity<TId>
     {
         public virtual TId Id { get; protected set; }
 
@@ -30,7 +30,7 @@ public override bool Equals(object obj)
             return Id.Equals(other.Id);
         }
 
-        private bool IsTransient()
+        public bool IsTransient()
         {
             return Id is null || Id.Equals(default(TId));
         }

CSharpFunctionalExtensions/Entity/IEntity.cs

@@ -0,0 +1,10 @@
+namespace CSharpFunctionalExtensions
+{
+    public interface IEntity<TId>
+    {
+        TId Id { get; }
+        bool Equals(object obj);
+        bool IsTransient();
+        int GetHashCode();
+    }
+}

CSharpFunctionalExtensions/IAggregateRoot.cs

@@ -0,0 +1,9 @@
+using System.Collections.Generic;
+
+namespace CSharpFunctionalExtensions
+{
+    public interface IAggregateRoot<TDomainEvent>
+    {
+        IEnumerable<TDomainEvent> DomainEvents { get; }
+    }
+}