Adding tests and domain events to Contributor

Author: ardalis

sample/src/NimblePros.SampleToDo.Core/ContributorAggregate/Contributor.cs

@@ -1,4 +1,6 @@
-namespace NimblePros.SampleToDo.Core.ContributorAggregate;
+using NimblePros.SampleToDo.Core.ContributorAggregate.Events;
+
+namespace NimblePros.SampleToDo.Core.ContributorAggregate;
 
 public class Contributor : EntityBase, IAggregateRoot
 {
@@ -11,6 +13,9 @@ public Contributor(ContributorName name)
 
   public void UpdateName(ContributorName newName)
   {
+    if (Name.Equals(newName)) return;
     Name = newName;
+    this.RegisterDomainEvent(new ContributorNameUpdatedEvent(this));
   }
 }
+

sample/src/NimblePros.SampleToDo.Core/ContributorAggregate/Events/ContributorDeletedEvent.cs

@@ -4,12 +4,7 @@
 /// A domain event that is dispatched whenever a contributor is deleted.
 /// The DeleteContributorService is used to dispatch this event.
 /// </summary>
-internal class ContributorDeletedEvent : DomainEventBase
+internal class ContributorDeletedEvent(int contributorId) : DomainEventBase
 {
-  public int ContributorId { get; set; }
-
-  public ContributorDeletedEvent(int contributorId)
-  {
-    ContributorId = contributorId;
-  }
+  public int ContributorId { get; set; } = contributorId;
 }

sample/src/NimblePros.SampleToDo.Core/ContributorAggregate/Events/ContributorNameUpdatedEvent.cs

@@ -0,0 +1,7 @@
+namespace NimblePros.SampleToDo.Core.ContributorAggregate.Events;
+
+internal class ContributorNameUpdatedEvent(Contributor contributor) : DomainEventBase
+{
+  public Contributor Contributor { get; private set; } = contributor;
+
+}

sample/tests/NimblePros.SampleToDo.UnitTests/Core/ContributorAggregate/ContributorConstructor.cs

@@ -20,3 +20,41 @@ public void InitializesName()
     Assert.Equal(_testName, _testContributor.Name.Value);
   }
 }
+
+public class ContributorUpdateName
+{
+  private readonly string _testName = "new name";
+  private Contributor? _testContributor;
+
+  private Contributor CreateContributor()
+  {
+    return new Contributor(ContributorName.From(_testName));
+  }
+
+  [Fact]
+  public void DoesNothingGivenSameName()
+  {
+    _testContributor = CreateContributor();
+    var initialEvents = _testContributor.DomainEvents.Count;
+
+    var initialHash = _testContributor.GetHashCode();
+
+    _testContributor.UpdateName(ContributorName.From(_testName));
+
+    Assert.Equal(initialHash, _testContributor.GetHashCode());
+    Assert.Equal(initialEvents, _testContributor.DomainEvents.Count);
+  }
+
+  [Fact]
+  public void UpdatesNameAndRegistersEventGivenNewName()
+  {
+    _testContributor = CreateContributor();
+    var initialEvents = _testContributor.DomainEvents.Count;
+    string newName = "A whole new name";
+
+    _testContributor.UpdateName(ContributorName.From(newName));
+
+    Assert.Equal(newName, _testContributor.Name.Value);
+    Assert.Equal(1, _testContributor.DomainEvents.Count);
+  }
+}