use null object pattern

PeterKneale · Apr 30, 2024 · d8d6c01 · d8d6c01
1 parent ca13f23
commit d8d6c01
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Showing 5 changed files with 23 additions and 35 deletions.
diff --git a/src/Micro.Common/Domain/OrganisationId.cs b/src/Micro.Common/Domain/OrganisationId.cs
@@ -2,7 +2,9 @@
 
 public record OrganisationId(Guid Value)
 {
+    public static OrganisationId Empty => new(Guid.Empty);
     public static OrganisationId Create() => new(Guid.NewGuid());
     public static OrganisationId Create(Guid guid) => new(guid);
+    public static OrganisationId Create(Guid? guid) => guid == null ? Empty : Create(guid.Value);
     public static implicit operator Guid(OrganisationId d) => d.Value;
 }
diff --git a/src/Micro.Common/Domain/ProjectId.cs b/src/Micro.Common/Domain/ProjectId.cs
@@ -2,7 +2,9 @@
 
 public record ProjectId(Guid Value)
 {
+    public static ProjectId Empty => new(Guid.Empty);
     public static ProjectId Create() => new(Guid.NewGuid());
     public static ProjectId Create(Guid guid) => new(guid);
+    public static ProjectId Create(Guid? guid) => guid == null ? Empty : Create(guid.Value);
     public static implicit operator Guid(ProjectId d) => d.Value;
 }
diff --git a/src/Micro.Common/Domain/UserId.cs b/src/Micro.Common/Domain/UserId.cs
@@ -2,7 +2,9 @@
 
 public record UserId(Guid Value)
 {
+    public static UserId Empty => new(Guid.Empty);
     public static UserId Create() => new(Guid.NewGuid());
     public static UserId Create(Guid guid) => new(guid);
+    public static UserId Create(Guid? guid) => guid == null ? Empty : Create(guid.Value);
     public static implicit operator Guid(UserId d) => d.Value;
 }
diff --git a/src/Micro.Common/Infrastructure/Context/ExecutionContext.cs b/src/Micro.Common/Infrastructure/Context/ExecutionContext.cs
@@ -5,44 +5,26 @@ namespace Micro.Common.Infrastructure.Context;
 
 public class ExecutionContext : IExecutionContext
 {
-    private readonly UserId? _userId;
-    private readonly OrganisationId? _organisationId;
-    private readonly ProjectId? _projectId;
+    private readonly UserId _userId;
+    private readonly OrganisationId _organisationId;
+    private readonly ProjectId _projectId;
 
-    private ExecutionContext(UserId? userId = null, OrganisationId? organisationId = null, ProjectId? projectId = null)
+    private ExecutionContext(UserId userId, OrganisationId organisationId, ProjectId projectId)
     {
         _userId = userId;
         _organisationId = organisationId;
         _projectId = projectId;
     }
 
-    private ExecutionContext(Guid? userId = null, Guid? organisationId = null, Guid? projectId = null)
-    {
-        if (userId != null)
-        {
-            _userId = UserId.Create(userId.Value);
-        }
-
-        if (organisationId != null)
-        {
-            _organisationId = OrganisationId.Create(organisationId.Value);
-        }
-
-        if (projectId != null)
-        {
-            _projectId = ProjectId.Create(projectId.Value);
-        }
-    }
-
-    public static ExecutionContext Create(UserId? userId = null, OrganisationId? organisationId = null, ProjectId? projectId = null) =>
-        new(userId, organisationId, projectId);
-
     public static ExecutionContext Create(Guid? userId = null, Guid? organisationId = null, Guid? projectId = null) =>
-        new(userId, organisationId, projectId);
+        new(UserId.Create(userId), OrganisationId.Create(organisationId), ProjectId.Create(projectId));
 
-    public UserId UserId => _userId ?? throw new ExecutionContextException("User ID is not set in the execution context");
+    public UserId UserId =>
+        _userId != UserId.Empty ? _userId : throw new ExecutionContextException("User ID is not set in the execution context");
 
-    public OrganisationId OrganisationId => _organisationId ?? throw new ExecutionContextException("Organisation ID is not set in the execution context");
+    public OrganisationId OrganisationId =>
+        _organisationId != OrganisationId.Empty ? _organisationId : throw new ExecutionContextException("Organisation ID is not set in the execution context");
 
-    public ProjectId ProjectId => _projectId ?? throw new ExecutionContextException("Project ID is not set in the execution context");
+    public ProjectId ProjectId =>
+        _projectId != ProjectId.Empty ? _projectId : throw new ExecutionContextException("Project ID is not set in the execution context");
 }
diff --git a/src/Micro.Web/Code/Contexts/Execution/HttpExecutionContextAccessor.cs b/src/Micro.Web/Code/Contexts/Execution/HttpExecutionContextAccessor.cs
@@ -14,16 +14,16 @@ public IExecutionContext ExecutionContext
             var authContext = new AuthContext(httpContextAccessor);
             var pageContext = new PageContextAccessor(httpContextAccessor);
 
-            var userId = authContext.IsAuthenticated 
-                ? UserId.Create(authContext.UserId) 
+            Guid? userId = authContext.IsAuthenticated
+                ? authContext.UserId
                 : null;
 
-            var organisationId = pageContext.HasOrganisation 
-                ? OrganisationId.Create(pageContext.Organisation.Id) 
+            Guid? organisationId = pageContext.HasOrganisation 
+                ? pageContext.Organisation.Id
                 : null;
 
-            var projectId = pageContext.HasProject 
-                ? ProjectId.Create(pageContext.Project.Id) 
+            Guid? projectId = pageContext.HasProject 
+                ? pageContext.Project.Id
                 : null;
 
             return Create(userId, organisationId, projectId);