我已经创建了一个包，Moq。ILogger，使测试ILogger扩展更容易。
实际上，您可以使用类似下面这样更接近实际代码的代码。
loggerMock.VerifyLog(c => c.LogInformation(
"Index page say hello",
It.IsAny<object[]>());
它不仅更容易编写新的测试，而且维护也没有成本。
回购可以在这里找到，也有一个nuget包(Install-Package ILogger.Moq)。
我也在博客上用一个现实生活中的例子解释了这一点。
简而言之，假设你有以下代码:
public class PaymentsProcessor
{
private readonly IOrdersRepository _ordersRepository;
private readonly IPaymentService _paymentService;
private readonly ILogger<PaymentsProcessor> _logger;
public PaymentsProcessor(IOrdersRepository ordersRepository,
IPaymentService paymentService,
ILogger<PaymentsProcessor> logger)
{
_ordersRepository = ordersRepository;
_paymentService = paymentService;
_logger = logger;
}
public async Task ProcessOutstandingOrders()
{
var outstandingOrders = await _ordersRepository.GetOutstandingOrders();
foreach (var order in outstandingOrders)
{
try
{
var paymentTransaction = await _paymentService.CompletePayment(order);
_logger.LogInformation("Order with {orderReference} was paid {at} by {customerEmail}, having {transactionId}",
order.OrderReference,
paymentTransaction.CreateOn,
order.CustomerEmail,
paymentTransaction.TransactionId);
}
catch (Exception e)
{
_logger.LogWarning(e, "An exception occurred while completing the payment for {orderReference}",
order.OrderReference);
}
}
_logger.LogInformation("A batch of {0} outstanding orders was completed", outstandingOrders.Count);
}
}
然后您可以编写一些测试，例如
[Fact]
public async Task Processing_outstanding_orders_logs_batch_size()
{
// Arrange
var ordersRepositoryMock = new Mock<IOrdersRepository>();
ordersRepositoryMock.Setup(c => c.GetOutstandingOrders())
.ReturnsAsync(GenerateOutstandingOrders(100));
var paymentServiceMock = new Mock<IPaymentService>();
paymentServiceMock
.Setup(c => c.CompletePayment(It.IsAny<Order>()))
.ReturnsAsync((Order order) => new PaymentTransaction
{
TransactionId = $"TRX-{order.OrderReference}"
});
var loggerMock = new Mock<ILogger<PaymentsProcessor>>();
var sut = new PaymentsProcessor(ordersRepositoryMock.Object, paymentServiceMock.Object, loggerMock.Object);
// Act
await sut.ProcessOutstandingOrders();
// Assert
loggerMock.VerifyLog(c => c.LogInformation("A batch of {0} outstanding orders was completed", 100));
}
[Fact]
public async Task Processing_outstanding_orders_logs_order_and_transaction_data_for_each_completed_payment()
{
// Arrange
var ordersRepositoryMock = new Mock<IOrdersRepository>();
ordersRepositoryMock.Setup(c => c.GetOutstandingOrders())
.ReturnsAsync(GenerateOutstandingOrders(100));
var paymentServiceMock = new Mock<IPaymentService>();
paymentServiceMock
.Setup(c => c.CompletePayment(It.IsAny<Order>()))
.ReturnsAsync((Order order) => new PaymentTransaction
{
TransactionId = $"TRX-{order.OrderReference}"
});
var loggerMock = new Mock<ILogger<PaymentsProcessor>>();
var sut = new PaymentsProcessor(ordersRepositoryMock.Object, paymentServiceMock.Object, loggerMock.Object);
// Act
await sut.ProcessOutstandingOrders();
// Assert
loggerMock.VerifyLog(logger => logger.LogInformation("Order with {orderReference} was paid {at} by {customerEmail}, having {transactionId}",
It.Is<string>(orderReference => orderReference.StartsWith("Reference")),
It.IsAny<DateTime>(),
It.Is<string>(customerEmail => customerEmail.Contains("@")),
It.Is<string>(transactionId => transactionId.StartsWith("TRX"))),
Times.Exactly(100));
}
[Fact]
public async Task Processing_outstanding_orders_logs_a_warning_when_payment_fails()
{
// Arrange
var ordersRepositoryMock = new Mock<IOrdersRepository>();
ordersRepositoryMock.Setup(c => c.GetOutstandingOrders())
.ReturnsAsync(GenerateOutstandingOrders(2));
var paymentServiceMock = new Mock<IPaymentService>();
paymentServiceMock
.SetupSequence(c => c.CompletePayment(It.IsAny<Order>()))
.ReturnsAsync(new PaymentTransaction
{
TransactionId = "TRX-1",
CreateOn = DateTime.Now.AddMinutes(-new Random().Next(100)),
})
.Throws(new Exception("Payment exception"));
var loggerMock = new Mock<ILogger<PaymentsProcessor>>();
var sut = new PaymentsProcessor(ordersRepositoryMock.Object, paymentServiceMock.Object, loggerMock.Object);
// Act
await sut.ProcessOutstandingOrders();
// Assert
loggerMock.VerifyLog(c => c.LogWarning(
It.Is<Exception>(paymentException => paymentException.Message.Contains("Payment exception")),
"*exception*Reference 2"));
}
