Captured scoped service (ARCH501)

Key dotnet.di.captured-scoped-service · Severity error · Category di · Principle DependencyInversion

Singleton services should not capture scoped services via constructor injection. Doing so makes the scoped service behave like a singleton and leaks the scope.

Incorrect

public class CacheManager
{
    private readonly OrderDbContext _context;

    public CacheManager(OrderDbContext context) // scoped, inside a singleton
    {
        _context = context;
    }
}

Correct

public class CacheManager
{
    private readonly IServiceScopeFactory _scopeFactory;

    public CacheManager(IServiceScopeFactory scopeFactory)
    {
        _scopeFactory = scopeFactory;
    }

    public void Refresh()
    {
        using var scope = _scopeFactory.CreateScope();
        var context = scope.ServiceProvider.GetRequiredService<OrderDbContext>();
    }
}

Fix

Access the scoped service from within the singleton by creating a scope through IServiceScopeFactory. If needed, suppress the rule per project/workspace via except/ignore.