feature(#59): Added decorator to allow global BCC address in all emails

src/Email/src/ContainerExtensions.cs

@@ -16,9 +16,10 @@ public static class ContainerExtensions
     /// <summary>
     /// Registers the components for sending emails.
     ///
-    /// Note: You need to register ViewLocalization in your services.
+    /// Note: You need to register ViewLocalization as well as the HtmlRenderer in your services.
     /// Example:
     /// <code>
+    /// services.AddScoped{HtmlRenderer}(); 
     /// services.AddLocalization(options => options.ResourcesPath = "Resources/Localization");
     ///
     /// services.AddMvc(options => options.Filters.Add(typeof(ExceptionFilter)))
@@ -48,5 +49,11 @@ public static void RegisterEmail(this Container container, Action<EmailOptions>
         container.Collection.Append<IEmailAttachmentResolver, FileAttachmentResolver>(Lifestyle.Singleton);
 
         container.Register(typeof(IRequestHandler<,>), Assembly.GetExecutingAssembly());
+
+        if (!string.IsNullOrWhiteSpace(options.BccAddress))
+        {
+            container.RegisterInstance(new SendEmailBccDecorator.Options(options.BccAddress));
+            container.RegisterDecorator<IRequestHandler<SendEmail, Unit>, SendEmailBccDecorator>();
+        }
     }
-}
+}

src/Email/src/EmailOptions.cs

@@ -16,6 +16,9 @@ public class EmailOptions
     /// <summary> Name of the sender. </summary>
     public string? SenderName { get; set; }
 
+    /// <summary> A fixed BCC address which will be set in every email. If another BCC address is set for a specific email, the address of the email has precedence. </summary>
+    public string? BccAddress { get; set; }
+
     /// <summary> Enable SSL connection to the mail server. Default is true. </summary>
     public bool EnableSsl { get; set; } = true;
 

src/Email/src/SendEmailBccDecorator.cs

@@ -0,0 +1,24 @@
+// Copyright (c) Fusonic GmbH. All rights reserved.
+// Licensed under the MIT License. See LICENSE file in the project root for license information.
+
+using Fusonic.Extensions.Mediator;
+
+namespace Fusonic.Extensions.Email;
+
+public class SendEmailBccDecorator(IRequestHandler<SendEmail, Unit> innerHandler, SendEmailBccDecorator.Options options) : IRequestHandler<SendEmail, Unit>
+{
+    public record Options(string BccAddress);
+
+    public Task<Unit> Handle(SendEmail request, CancellationToken cancellationToken)
+    {
+        if (string.IsNullOrWhiteSpace(request.BccRecipient))
+        {
+            request = request with
+            {
+                BccRecipient = options.BccAddress
+            };
+        }
+
+        return innerHandler.Handle(request, cancellationToken);
+    }
+}

src/Email/test/SendEmailBccDecoratorTests.cs

@@ -0,0 +1,76 @@
+// Copyright (c) Fusonic GmbH. All rights reserved.
+// Licensed under the MIT License. See LICENSE file in the project root for license information.
+
+using System.Globalization;
+using FluentAssertions;
+using Fusonic.Extensions.Email.Tests.Models;
+using netDumbster.smtp;
+using SimpleInjector;
+using Xunit;
+
+namespace Fusonic.Extensions.Email.Tests;
+
+public class SendEmailBccDecoratorTests(SendEmailBccDecoratorTests.SendEmailBccDecoratorTestsFixture fixture) : TestBase<SendEmailBccDecoratorTests.SendEmailBccDecoratorTestsFixture>(fixture)
+{
+    [Fact]
+    public async Task SendEmail_NoBccDefined_SetsConfiguredBccAddress()
+    {
+        Fixture.SmtpServer!.ClearReceivedEmail();
+
+        var model = new SendEmailTestEmailViewModel { SomeField = "Some field." };
+        await SendAsync(new SendEmail("[email protected]", "The Recipient", new CultureInfo("de-AT"), model));
+
+        Fixture.SmtpServer.ReceivedEmailCount.Should().Be(1);
+        var email = Fixture.SmtpServer.ReceivedEmail.Single();
+        email.ToAddresses
+             .Should()
+             .HaveCount(2)
+             .And.Contain(a => a.Address == "[email protected]")
+             .And.Contain(a => a.Address == "[email protected]");
+    }
+
+    [Fact]
+    public async Task SendEmail_BccDefined_ConfiguredBccAddressDoesNotOverwrite()
+    {
+        Fixture.SmtpServer!.ClearReceivedEmail();
+
+        var model = new SendEmailTestEmailViewModel { SomeField = "Some field." };
+        await SendAsync(new SendEmail("[email protected]", "The Recipient", new CultureInfo("de-AT"), model, BccRecipient: "[email protected]"));
+
+        Fixture.SmtpServer.ReceivedEmailCount.Should().Be(1);
+        var email = Fixture.SmtpServer.ReceivedEmail.Single();
+        email.ToAddresses
+             .Should()
+             .HaveCount(2)
+             .And.Contain(a => a.Address == "[email protected]")
+             .And.Contain(a => a.Address == "[email protected]");
+    }
+
+    public class SendEmailBccDecoratorTestsFixture : TestFixture
+    {
+        public SimpleSmtpServer? SmtpServer { get; private set; }
+
+        protected override void RegisterDependencies(Container container)
+        {
+            base.RegisterDependencies(container);
+
+            SmtpServer = SimpleSmtpServer.Start();
+
+            container.RegisterEmail(c =>
+            {
+                c.CssPath = "email.css";
+                c.SmtpServer = "localhost";
+                c.SmtpPort = SmtpServer.Configuration.Port;
+                c.SenderAddress = "[email protected]";
+                c.SenderName = "Test Fusonic";
+                c.BccAddress = "[email protected]";
+            });
+        }
+
+        public override async ValueTask DisposeAsync()
+        {
+            SmtpServer?.Dispose();
+            await base.DisposeAsync();
+        }
+    }
+}