unittest-example-8.cs

unittest-example-8.cs

// We solving the first issue by injected the real dependencies that the class depend on directly, and not injecting the whole
// ServiceLocator.
// And we solving the 2nd issue by implementing an IdentityService that we depend on to get the UserName directly.

public class PrintInvoiceCommand
    {
        private readonly IDatabase _database;
        private readonly IInvoiceWriter _writer;
        private readonly IIdentityService _identity;

        public PrintInvoiceCommand(
            IDatabase database,
            IInvoiceWriter writer,
            IIdentityService identity)
        {
            _database = database;
            _writer = writer;
            _identity = identity;
        }

        public void Execute(int invoiceId)
        {
            var invoice = _database.GetInvoice(invoiceId);

            _writer.Write(invoice);

            invoice.LastPrintedBy = _identity.GetUserName();

            _database.Save();
        }
    }