DependencyInjection.Lifetime.Analyzers

DI017

Circular Dependency

constructor-injection cycles such as `A -> B -> A`, including longer transitive loops. It stays silent when constructor selection is ambiguous rather than guessing which path the container will choose.

Default severity: Warning · Code fix: No

Why it matters

the default DI container cannot resolve circular constructor graphs and will fail at runtime when the service is activated.

If two people each wait for the other to hand over the key first, the door never opens.

README problem example

services.AddScoped<IOrderService, OrderService>();
services.AddScoped<IPaymentService, PaymentService>();

public sealed class OrderService : IOrderService
{
    public OrderService(IPaymentService payment) { }
}

public sealed class PaymentService : IPaymentService
{
    public PaymentService(IOrderService order) { }
}

README better pattern

No. Breaking dependency cycles is a design change.

Repo sample extraction

Examples pulled from the sample app

Open full sample file

Sample app circular dependency

public class BadOrderService : IOrderService
{
    public BadOrderService(IPaymentService payment) { }
}

Sample app safe pattern

public class GoodOrderService : IOrderService { }

Related guides

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