DependencyInjection.Lifetime.Analyzers

DI015

Unresolvable Dependency

Registered services with direct or transitive constructor/factory dependencies that are not registered (including keyed and open-generic paths). Type parameters and closed generics containing them are not reported as missing, because the closed type is unknown. A non-generic DbContextOptions dependency is satisfied by any registered DbContextOptions<TContext>.

Warning Default severity · Code fix: Yes

Why it matters

Runtime activation fails when DI tries to create the service.

Planning to build a kite without string means the build fails when you start.

README problem example

public interface IMissingDependency { }
public interface IMyService { }

public sealed class MyService : IMyService
{
    public MyService(IMissingDependency missing) { }
}

services.AddSingleton<IMyService, MyService>();

README better pattern

public sealed class MissingDependency : IMissingDependency { }

services.AddScoped<IMissingDependency, MissingDependency>();
services.AddSingleton<IMyService, MyService>();

Yes. Adds a missing self-binding registration when DI015 can prove a single direct concrete class dependency is safe to register. Supports local constructor diagnostics, TryAdd* registration sites, local IServiceCollection aliases, direct GetRequiredService<TConcrete>() factory diagnostics, and keyed self-bindings when the key can be emitted as a C# literal.

Repo sample extraction

Examples pulled from the sample app

Open full sample file

Sample app warning case

public class BadUnresolvableService
{
    public BadUnresolvableService(IMissingDependency missing) { }
}

Sample app safe pattern

public class GoodResolvableService
{
    public GoodResolvableService(IRegisteredDependency dependency) { }
}

Nearby diagnostics

Other rules in this family

All 37 rules