feat: consume transactional email notifications

Add contract validation, SMTP delivery results, terminal failure context, neutral development seeding, and local Docker setup. Ref: IT-1033
2026-08-04 12:32:28 +03:00
parent b8435ac07b
commit 2757869176
37 changed files with 1465 additions and 122 deletions
@@ -0,0 +1,67 @@
+namespace HrynCo.NotificationService.Services.Tests.EmailProcessing;
+
+using HrynCo.NotificationService.Contracts.Messages;
+using HrynCo.NotificationService.DAL.Abstract.Templates;
+using HrynCo.NotificationService.Worker.Services.EmailProcessing;
+
+public sealed class EmailTemplateRenderingServiceTests
+{
+    private readonly EmailTemplateRenderingService _service = new();
+
+    [Fact]
+    public void Render_InterpolatesItemTrackerVariables()
+    {
+        EmailTemplate template = CreateTemplate();
+        SendEmailMessageData data = CreateData(new Dictionary<string, string>
+        {
+            ["AppName"] = "StoreMate",
+            ["VerificationUrl"] = "https://example.invalid/verify"
+        });
+
+        RenderedEmail result = _service.Render(template, data);
+
+        Assert.Equal("Verify StoreMate", result.Subject);
+        Assert.Equal("<a href=\"https://example.invalid/verify\">Verify</a>", result.HtmlBody);
+        Assert.Equal("Verify at https://example.invalid/verify", result.TextBody);
+    }
+
+    [Fact]
+    public void Render_WhenRequiredVariableIsMissing_ThrowsObservableFailure()
+    {
+        EmailTemplate template = CreateTemplate();
+        SendEmailMessageData data = CreateData(new Dictionary<string, string>
+        {
+            ["AppName"] = "StoreMate"
+        });
+
+        InvalidDataException exception = Assert.Throws<InvalidDataException>(
+            () => _service.Render(template, data));
+
+        Assert.Equal("Required template variables are missing: VerificationUrl.", exception.Message);
+    }
+
+    private static EmailTemplate CreateTemplate() => new()
+    {
+        ServiceName = "StoreMate-Prod",
+        Key = "EmailVerification",
+        LanguageCode = "uk",
+        Subject = "Verify {{AppName}}",
+        HtmlBody = "<a href=\"{{VerificationUrl}}\">Verify</a>",
+        TextBody = "Verify at {{VerificationUrl}}",
+        Variables =
+        [
+            new EmailTemplateVariable { Name = "AppName", Required = true },
+            new EmailTemplateVariable { Name = "VerificationUrl", Required = true }
+        ]
+    };
+
+    private static SendEmailMessageData CreateData(IReadOnlyDictionary<string, string> variables) => new()
+    {
+        ServiceName = "StoreMate-Prod",
+        TemplateKey = "EmailVerification",
+        RecipientEmail = "owner@example.com",
+        RecipientName = "Owner",
+        LanguageCode = "uk",
+        Variables = variables
+    };
+}
@@ -0,0 +1,30 @@
+namespace HrynCo.NotificationService.Services.Tests.EmailProcessing;
+
+using HrynCo.NotificationService.DAL.Abstract.Repositories;
+using HrynCo.NotificationService.Worker.Services.EmailProcessing;
+using NSubstitute;
+
+public sealed class EmailTemplateServiceTests
+{
+    [Fact]
+    public async Task GetAsync_WhenRequestedLanguageDoesNotExist_DoesNotSilentlyFallback()
+    {
+        IEmailTemplateRepository repository = Substitute.For<IEmailTemplateRepository>();
+        var service = new EmailTemplateService(repository);
+
+        InvalidOperationException exception = await Assert.ThrowsAsync<InvalidOperationException>(
+            () => service.GetAsync("StoreMate-Prod", "EmailVerification", "UK", CancellationToken.None));
+
+        Assert.Contains("language='uk'", exception.Message);
+        await repository.Received(1).GetAsync(
+            "StoreMate-Prod",
+            "EmailVerification",
+            "uk",
+            CancellationToken.None);
+        await repository.DidNotReceive().GetAsync(
+            "StoreMate-Prod",
+            "EmailVerification",
+            "en",
+            Arg.Any<CancellationToken>());
+    }
+}
@@ -0,0 +1,58 @@
+namespace HrynCo.NotificationService.Services.Tests.EmailProcessing;
+
+using HrynCo.NotificationService.Worker.Services.EmailProcessing;
+using System.Net.Mail;
+using System.Net.Sockets;
+
+public sealed class NotificationDeliveryErrorFormatterTests
+{
+    [Fact]
+    public void Format_UsesInnermostMessageAndRemovesLineBreaks()
+    {
+        var exception = new InvalidOperationException(
+            "outer",
+            new Exception("provider failed\r\nretry rejected"));
+
+        string result = NotificationDeliveryErrorFormatter.Format(exception);
+
+        Assert.Equal(
+            "Notification delivery failed after all retry attempts (provider failed retry rejected).",
+            result);
+    }
+
+    [Fact]
+    public void Format_UnresolvedSmtpHost_AddsSafeChannelContext()
+    {
+        var socketException = new SocketException((int)SocketError.HostNotFound);
+        var exception = new SmtpException("Failure sending mail.", socketException);
+
+        string result = NotificationDeliveryErrorFormatter.Format(exception);
+
+        Assert.Equal(
+            $"SMTP delivery failed after all retry attempts: the configured SMTP server host could not be resolved ({socketException.Message}).",
+            result);
+    }
+
+    [Fact]
+    public void Format_RefusedSmtpConnection_AddsSafeChannelContext()
+    {
+        var socketException = new SocketException((int)SocketError.ConnectionRefused);
+        var exception = new SmtpException("Failure sending mail.", socketException);
+
+        string result = NotificationDeliveryErrorFormatter.Format(exception);
+
+        Assert.Equal(
+            $"SMTP delivery failed after all retry attempts: the configured SMTP server refused the connection ({socketException.Message}).",
+            result);
+    }
+
+    [Fact]
+    public void Format_LongError_IsBoundedToOutboxColumnLength()
+    {
+        var exception = new Exception(new string('x', 2100));
+
+        string result = NotificationDeliveryErrorFormatter.Format(exception);
+
+        Assert.Equal(2000, result.Length);
+    }
+}
@@ -0,0 +1,107 @@
+namespace HrynCo.NotificationService.Services.Tests.EmailProcessing;
+
+using HrynCo.NotificationService.Contracts.Messages;
+using HrynCo.NotificationService.Worker.Services.EmailProcessing;
+using Hrynco.RabbitMq;
+using Microsoft.Extensions.Logging.Abstractions;
+using NSubstitute;
+
+public sealed class NotificationResultPublisherTests
+{
+    [Fact]
+    public async Task PublishAsync_TerminalFailure_PublishesNeutralFailureResultToReplyQueue()
+    {
+        IRabbitMqPublisher rabbitMqPublisher = Substitute.For<IRabbitMqPublisher>();
+        var publisher = new NotificationResultPublisher(
+            rabbitMqPublisher,
+            NullLogger<NotificationResultPublisher>.Instance);
+        SendEmailMessage message = CreateMessage();
+        NotificationResultMessage? publishedResult = null;
+        rabbitMqPublisher
+            .When(x => x.PublishAsync(
+                "item-tracker.notifications.result",
+                Arg.Any<NotificationResultMessage>(),
+                Arg.Any<CancellationToken>()))
+            .Do(call => publishedResult = call.ArgAt<NotificationResultMessage>(1));
+
+        await publisher.PublishAsync(
+            message,
+            "Email provider could not deliver the notification.",
+            CancellationToken.None);
+
+        await rabbitMqPublisher.Received(1).PublishAsync(
+            "item-tracker.notifications.result",
+            Arg.Any<NotificationResultMessage>(),
+            CancellationToken.None);
+        Assert.NotNull(publishedResult);
+        Assert.Equal(message.CorrelationContext.CorrelationId, publishedResult.CorrelationContext.CorrelationId);
+        Assert.Null(publishedResult.CorrelationContext.ReplyTo);
+        Assert.Equal(message.Data.ServiceName, publishedResult.Data.ServiceName);
+        Assert.Equal(message.Data.TemplateKey, publishedResult.Data.TemplateKey);
+        Assert.Equal(message.Data.RecipientEmail, publishedResult.Data.RecipientEmail);
+        Assert.Equal("Email provider could not deliver the notification.", publishedResult.Data.ErrorMessage);
+        Assert.False(publishedResult.Data.IsSuccess);
+    }
+
+    [Fact]
+    public async Task PublishAsync_NoReplyQueue_DoesNotPublish()
+    {
+        IRabbitMqPublisher rabbitMqPublisher = Substitute.For<IRabbitMqPublisher>();
+        var publisher = new NotificationResultPublisher(
+            rabbitMqPublisher,
+            NullLogger<NotificationResultPublisher>.Instance);
+        SendEmailMessage message = CreateMessage();
+        message.CorrelationContext = message.CorrelationContext with { ReplyTo = null };
+
+        await publisher.PublishAsync(message, "delivery failed", CancellationToken.None);
+
+        await rabbitMqPublisher.DidNotReceive()
+            .PublishAsync<NotificationResultData>(
+                Arg.Any<string>(),
+                Arg.Any<NotificationResultMessage>(),
+                Arg.Any<CancellationToken>());
+    }
+
+    [Fact]
+    public async Task PublishAsync_ResultBrokerFailure_IsBestEffort()
+    {
+        IRabbitMqPublisher rabbitMqPublisher = Substitute.For<IRabbitMqPublisher>();
+        rabbitMqPublisher
+            .PublishAsync(
+                Arg.Any<string>(),
+                Arg.Any<NotificationResultMessage>(),
+                Arg.Any<CancellationToken>())
+            .Returns<Task>(_ => throw new InvalidOperationException("reply broker unavailable"));
+        var publisher = new NotificationResultPublisher(
+            rabbitMqPublisher,
+            NullLogger<NotificationResultPublisher>.Instance);
+
+        Exception? exception = await Record.ExceptionAsync(() => publisher.PublishAsync(
+            CreateMessage(),
+            "delivery failed",
+            CancellationToken.None));
+
+        Assert.Null(exception);
+    }
+
+    private static SendEmailMessage CreateMessage()
+    {
+        return new SendEmailMessage
+        {
+            CorrelationContext = new CorrelationContext
+            {
+                CorrelationId = "correlation-id",
+                ReplyTo = "item-tracker.notifications.result"
+            },
+            Data = new SendEmailMessageData
+            {
+                ServiceName = "TestService",
+                TemplateKey = "TestEmail",
+                RecipientEmail = "test.user@itemtracker.local",
+                RecipientName = "Test User",
+                LanguageCode = "en",
+                Variables = new Dictionary<string, string>()
+            }
+        };
+    }
+}
@@ -0,0 +1,16 @@
+namespace HrynCo.NotificationService.Services.Tests.EmailProcessing;
+
+using HrynCo.NotificationService.Worker.Services.EmailProcessing;
+
+public sealed class RecipientAddressRedactorTests
+{
+    [Theory]
+    [InlineData("owner@example.com", "o***@e***.com")]
+    [InlineData("a@b.test", "a***@b***.test")]
+    [InlineData("invalid", "***")]
+    [InlineData(null, "<missing>")]
+    public void Redact_DoesNotExposeFullAddress(string? address, string expected)
+    {
+        Assert.Equal(expected, RecipientAddressRedactor.Redact(address));
+    }
+}
@@ -0,0 +1,60 @@
+namespace HrynCo.NotificationService.Services.Tests.EmailProcessing;
+
+using System.Text.Json;
+using HrynCo.NotificationService.Contracts.Messages;
+using HrynCo.NotificationService.Worker.Services.EmailProcessing;
+
+public sealed class SendEmailContractTests
+{
+    private const string ItemTrackerPayload = """
+        {
+          "CorrelationContext": {
+            "CorrelationId": "3ec4ad3f-0a8a-49f3-b31d-cdad5d1b95cc",
+            "ReplyTo": "item-tracker.notifications.result"
+          },
+          "Data": {
+            "ServiceName": "StoreMate-Prod",
+            "TemplateKey": "EmailVerification",
+            "RecipientEmail": "owner@example.com",
+            "RecipientName": "StoreMate Owner",
+            "Variables": {
+              "AppName": "StoreMate",
+              "VerificationUrl": "https://example.invalid/sensitive-token"
+            },
+            "LanguageCode": "uk"
+          }
+        }
+        """;
+
+    [Fact]
+    public void PascalCaseItemTrackerPayload_DeserializesWithoutLosingValues()
+    {
+        SendEmailMessage? message = JsonSerializer.Deserialize<SendEmailMessage>(ItemTrackerPayload);
+
+        Assert.NotNull(message);
+        SendEmailMessageValidator.Validate(message);
+        Assert.Equal("3ec4ad3f-0a8a-49f3-b31d-cdad5d1b95cc", message.CorrelationContext.CorrelationId);
+        Assert.Equal("item-tracker.notifications.result", message.CorrelationContext.ReplyTo);
+        Assert.Equal("StoreMate-Prod", message.Data.ServiceName);
+        Assert.Equal("EmailVerification", message.Data.TemplateKey);
+        Assert.Equal("owner@example.com", message.Data.RecipientEmail);
+        Assert.Equal("StoreMate Owner", message.Data.RecipientName);
+        Assert.Equal("uk", message.Data.LanguageCode);
+        Assert.Equal("StoreMate", message.Data.Variables["AppName"]);
+        Assert.Equal(
+            "https://example.invalid/sensitive-token",
+            message.Data.Variables["VerificationUrl"]);
+    }
+
+    [Fact]
+    public void MissingLanguageCode_IsRejected()
+    {
+        SendEmailMessage? message = JsonSerializer.Deserialize<SendEmailMessage>(
+            ItemTrackerPayload.Replace("\"uk\"", "null", StringComparison.Ordinal));
+
+        InvalidDataException exception = Assert.Throws<InvalidDataException>(
+            () => SendEmailMessageValidator.Validate(message!));
+
+        Assert.Equal("LanguageCode is required.", exception.Message);
+    }
+}
@@ -0,0 +1,77 @@
+namespace HrynCo.NotificationService.Services.Tests.EmailProcessing;
+
+using HrynCo.NotificationService.Contracts.Messages;
+using HrynCo.NotificationService.Worker;
+using Hrynco.RabbitMq;
+
+public sealed class SendEmailDeliveryValidatorTests
+{
+    [Fact]
+    public void ValidItemTrackerDelivery_IsAccepted()
+    {
+        string? error = SendEmailDeliveryValidator.GetValidationError(
+            CreateMessage(),
+            CreateContext(),
+            SendEmailConsumer.SupportedMessageType);
+
+        Assert.Null(error);
+    }
+
+    [Fact]
+    public void MissingMessageId_IsRejected()
+    {
+        RabbitMqMessageContext context = CreateContext() with { MessageId = null };
+
+        string? error = SendEmailDeliveryValidator.GetValidationError(
+            CreateMessage(),
+            context,
+            SendEmailConsumer.SupportedMessageType);
+
+        Assert.Equal("AMQP MessageId is required.", error);
+    }
+
+    [Fact]
+    public void UnsupportedContractVersion_IsRejected()
+    {
+        RabbitMqMessageContext context = CreateContext() with
+        {
+            MessageType = "Notification.SendEmail.v2"
+        };
+
+        string? error = SendEmailDeliveryValidator.GetValidationError(
+            CreateMessage(),
+            context,
+            SendEmailConsumer.SupportedMessageType);
+
+        Assert.Equal("Unsupported AMQP message type 'Notification.SendEmail.v2'.", error);
+    }
+
+    private static RabbitMqMessageContext CreateContext() => new()
+    {
+        QueueName = SendEmailConsumer.IncomingQueue,
+        Exchange = string.Empty,
+        RoutingKey = SendEmailConsumer.IncomingQueue,
+        MessageId = Guid.NewGuid().ToString("D"),
+        MessageType = SendEmailConsumer.SupportedMessageType,
+        CorrelationId = "correlation-id",
+        ContentType = "application/json"
+    };
+
+    private static SendEmailMessage CreateMessage() => new()
+    {
+        CorrelationContext = new CorrelationContext
+        {
+            CorrelationId = "correlation-id",
+            ReplyTo = "item-tracker.notifications.result"
+        },
+        Data = new SendEmailMessageData
+        {
+            ServiceName = "StoreMate-Prod",
+            TemplateKey = "EmailVerification",
+            RecipientEmail = "owner@example.com",
+            RecipientName = "Owner",
+            LanguageCode = "uk",
+            Variables = new Dictionary<string, string> { ["AppName"] = "StoreMate" }
+        }
+    };
+}
@@ -0,0 +1,123 @@
+namespace HrynCo.NotificationService.Services.Tests.EmailProcessing;
+
+using HrynCo.NotificationService.Contracts.Messages;
+using HrynCo.NotificationService.DAL.Abstract.Providers;
+using HrynCo.NotificationService.DAL.Abstract.Repositories;
+using HrynCo.NotificationService.DAL.Abstract.Templates;
+using HrynCo.NotificationService.Worker.Services.EmailProcessing;
+using Hrynco.RabbitMq;
+using Microsoft.Extensions.Logging.Abstractions;
+using NSubstitute;
+
+public sealed class SendEmailServiceTests
+{
+    [Fact]
+    public async Task ProcessAsync_ValidItemTrackerMessage_SendsOnceAndUpdatesUsage()
+    {
+        Guid channelId = Guid.NewGuid();
+        var settings = new SmtpChannelSettings
+        {
+            Host = "smtp.example.invalid",
+            Port = 587,
+            Username = "smtp-user",
+            Password = "not-a-real-secret",
+            UseSsl = true,
+            FromEmail = "notifications@example.com",
+            FromName = "StoreMate"
+        };
+        var channel = new EmailChannel
+        {
+            Id = channelId,
+            ServiceName = "StoreMate-Prod",
+            Priority = 1,
+            EmailChannelType = EmailChannelType.Smtp,
+            Settings = settings,
+            IsActive = true
+        };
+        var template = new EmailTemplate
+        {
+            ServiceName = "StoreMate-Prod",
+            Key = "EmailVerification",
+            LanguageCode = "uk",
+            Subject = "Verify {{AppName}}",
+            HtmlBody = "<p>{{AppName}}</p>",
+            TextBody = "{{AppName}}",
+            Variables = [new EmailTemplateVariable { Name = "AppName", Required = true }]
+        };
+
+        IEmailChannelRepository channels = Substitute.For<IEmailChannelRepository>();
+        channels.GetByServiceAsync("StoreMate-Prod", Arg.Any<CancellationToken>())
+            .Returns([channel]);
+        IEmailChannelUsageRepository usage = Substitute.For<IEmailChannelUsageRepository>();
+        IEmailTemplateService templates = Substitute.For<IEmailTemplateService>();
+        templates.GetAsync("StoreMate-Prod", "EmailVerification", "uk", Arg.Any<CancellationToken>())
+            .Returns(template);
+        var renderer = new EmailTemplateRenderingService();
+        var smtp = new RecordingSmtpEmailSender();
+        INotificationResultPublisher resultPublisher = Substitute.For<INotificationResultPublisher>();
+        var service = new SendEmailService(
+            channels,
+            usage,
+            templates,
+            renderer,
+            smtp,
+            resultPublisher,
+            NullLogger<SendEmailService>.Instance);
+        var message = new SendEmailMessage
+        {
+            CorrelationContext = new CorrelationContext
+            {
+                CorrelationId = Guid.NewGuid().ToString("D")
+            },
+            Data = new SendEmailMessageData
+            {
+                ServiceName = "StoreMate-Prod",
+                TemplateKey = "EmailVerification",
+                RecipientEmail = "owner@example.com",
+                RecipientName = "Owner",
+                LanguageCode = "uk",
+                Variables = new Dictionary<string, string> { ["AppName"] = "StoreMate" }
+            }
+        };
+
+        await service.ProcessAsync(message, CancellationToken.None);
+
+        Assert.Equal(1, smtp.SendCount);
+        Assert.Same(settings, smtp.Settings);
+        Assert.Equal("Verify StoreMate", smtp.Email?.Subject);
+        Assert.Equal("owner@example.com", smtp.RecipientEmail);
+        Assert.Equal("Owner", smtp.RecipientName);
+        await usage.Received(1).IncrementUsageAsync(
+            channelId,
+            Arg.Any<DateOnly>(),
+            CancellationToken.None);
+        await resultPublisher.Received(1).PublishAsync(
+            message,
+            null,
+            CancellationToken.None);
+    }
+
+    private sealed class RecordingSmtpEmailSender : ISmtpEmailSender
+    {
+        public int SendCount { get; private set; }
+        public SmtpChannelSettings? Settings { get; private set; }
+        public RenderedEmail? Email { get; private set; }
+        public string? RecipientEmail { get; private set; }
+        public string? RecipientName { get; private set; }
+
+        public Task SendAsync(
+            SmtpChannelSettings settings,
+            RenderedEmail email,
+            string recipientEmail,
+            string recipientName,
+            CancellationToken cancellationToken)
+        {
+            SendCount++;
+            Settings = settings;
+            Email = email;
+            RecipientEmail = recipientEmail;
+            RecipientName = recipientName;
+            return Task.CompletedTask;
+        }
+    }
+}