DSoftStudio.Mediator.Abstractions 1.2.0

DSoftStudio.Mediator.Abstractions

Contracts (interfaces and base types) for DSoftStudio.Mediator. Reference this package in domain, application-core, and test projects that need ISender, IPublisher, IMediator, IRequest, INotification, and related abstractions — without pulling in the runtime or source generators.

Installation

dotnet add package DSoftStudio.Mediator.Abstractions

When to Use This Package

This is the recommended architecture for testability. See the cross-project-mocking sample for a complete working example.

Included Interfaces

Dispatchers

Requests & Handlers

Notifications

Streams

Pipeline

Types

Usage Examples

Define a command and handler

using DSoftStudio.Mediator.Abstractions;

// Command (write operation)
public sealed record CreateOrderCommand(string ProductName, int Quantity) : ICommand<int>;

public sealed class CreateOrderCommandHandler : ICommandHandler<CreateOrderCommand, int>
{
    public ValueTask<int> Handle(CreateOrderCommand request, CancellationToken ct)
    {
        // ... create order logic
        return new(orderId);
    }
}

Define a query and handler

// Query (read operation)
public sealed record GetOrderQuery(int OrderId) : IQuery<string>;

public sealed class GetOrderQueryHandler : IQueryHandler<GetOrderQuery, string>
{
    public ValueTask<string> Handle(GetOrderQuery request, CancellationToken ct)
    {
        return new($"Order #{request.OrderId}");
    }
}

Define a notification and handler

public sealed record OrderPlaced(int OrderId) : INotification;

public sealed class SendOrderEmail : INotificationHandler<OrderPlaced>
{
    public Task Handle(OrderPlaced notification, CancellationToken ct)
    {
        // ... send email
        return Task.CompletedTask;
    }
}

Define a pipeline behavior

public sealed class LoggingBehavior<TRequest, TResponse>
    : IPipelineBehavior<TRequest, TResponse>
    where TRequest : IRequest<TResponse>
{
    public async ValueTask<TResponse> Handle(
        TRequest request,
        IRequestHandler<TRequest, TResponse> next,
        CancellationToken ct)
    {
        Console.WriteLine($"Handling {typeof(TRequest).Name}");
        var response = await next.Handle(request, ct);
        Console.WriteLine($"Handled {typeof(TRequest).Name}");
        return response;
    }
}

Mock ISender in tests

// Always use the explicit two-generic-parameter form:
var sender = new Mock<ISender>();
sender.Setup(s => s.Send<CreateOrderCommand, int>(
        It.IsAny<CreateOrderCommand>(), It.IsAny<CancellationToken>()))
    .ReturnsAsync(1001);

Target Framework

This package targets .NET Standard 2.0 — compatible with .NET 8+, .NET Framework 4.6.1+, and any runtime that supports .NET Standard 2.0.

Related Packages

Documentation

Full documentation: docs.dsoftstudio.com/mediator

License

MIT