Overview

The DeleteBasketFailedCommand is an integration event published by the Finance service when a basket deletion operation fails during the order processing workflow. This command is part of the error handling mechanism in the order processing saga and is used to notify other services about the failure, allowing them to take appropriate recovery actions.

Architecture

Message Structure

The command contains the following properties:

Workflow Context

This command is published by the Order State Machine when the following conditions are met:

1. The order is in the Placed state
2. A BasketDeletedFailedIntegrationEvent is received
3. The order transitions to the Failed state
4. The command is published to notify downstream services

Technical Implementation

The DeleteBasketFailedCommand is implemented as follows:

[AsyncApi]
[Channel("basket-checkout-failed")]
[SubscribeOperation(
    typeof(DeleteBasketFailedCommand),
    OperationId = nameof(DeleteBasketFailedCommand),
    Summary = "Delete basket failed"
)]
public sealed record DeleteBasketFailedCommand(
    Guid BasketId,
    string? Email,
    Guid OrderId,
    decimal TotalMoney
) : IntegrationEvent;

Within the Order State Machine, the command is published during the state transition:

When(BasketDeletedFailed)
    .Then(context =>
    {
        context.Saga.OrderId = context.Message.OrderId;
        context.Saga.BasketId = context.Message.BasketId;
        context.Saga.Email = context.Message.Email;
        context.Saga.TotalMoney = context.Message.TotalMoney;

        logger.LogInformation(
            "[{Event}] Basket deletion failed for {OrderId}",
            nameof(BasketDeletedFailed),
            context.Message.OrderId
        );
    })
    .TransitionTo(Failed)
    .Publish(context => new DeleteBasketFailedCommand(
        context.Saga.BasketId,
        context.Saga.Email,
        context.Saga.OrderId,
        context.Saga.TotalMoney.GetValueOrDefault(0.0M)
    ))

Error Handling

This command plays a critical role in the error handling flow of the order processing saga:

1. When a basket deletion fails, the saga transitions to the Failed state
2. The DeleteBasketFailedCommand is published to notify downstream services
3. Downstream services can implement recovery mechanisms or compensating transactions
4. The customer may be notified about the failure if an email address is available

Consuming Services

This command is typically consumed by:

• Notification Service: To send failure notifications to customers
• Ordering Service: To roll back the order