我试图测试我的Akka.NET演员,但是对TestKit有一些麻烦,并了解它的工作原理.
由于Akka.NET目前没有用于单元测试的官方文档,所以我已经开发了Akka.NET repo代码,但是在这里使用的例子并不适用于我.
我用来参考的测试是ReceiveActorTests.cs和ReceiveActorTests_Become.cs,因为那些接近我在我的应用程序中测试的场景.
这里有一些虚拟代码：
给这个演员
public class Greeter : ReceiveActor
{
public Greeter()
{
NotGreeted();
}
private void NotGreeted()
{
Receive<Greeting>(msg => Handle(msg));
}
private void Greeted()
{
Receive<Farewell>(msg => Handle(msg));
}
private void Handle(Greeting msg)
{
if (msg.Message == "hello")
{
Become(Greeted);
}
}
private void Handle(Farewell msg)
{
if (msg.Message == "bye bye")
{
Become(NotGreeted);
}
}
}
我想测试它正确接收到问候和告别消息,并进入正确的状态.看看ReceiveActorTests_Become.cs测试,一个演员是由…创建的
var system = ActorSystem.Create("test");
var actor = system.ActorOf<BecomeActor>("become");
并发送和断言的消息
actor.Tell(message,TestActor); ExpectMsg(message);
然而,当我尝试这种方法来实例化一个演员,还有许多其他的基于TestKit方法(见下文),我不断得到samme失败的测试错误：
Xunit.Sdk.TrueExceptionFailed: Timeout 00:00:03 while waiting for a message of type ConsoleApplication1.Greeting Expected: True Actual: False
这是我的考验
public class XUnit_GreeterTests : TestKit
{
[Fact]
public void BecomesGreeted()
{
//var system = ActorSystem.Create("test-system"); // Timeout error
//var actor = system.ActorOf<Greeter>("greeter"); // Timeout error
//var actor = ActorOfAsTestActorRef<Greeter>("greeter"); // Timeout error
//var actor = ActorOf(() => new Greeter(),"greeter"); // Timeout error
//var actor = Sys.ActorOf<Greeter>("greeter"); // Timeout error
//var actor = Sys.ActorOf(Props.Create<Greeter>(),"greeter"); // Timeout error
var actor = CreateTestActor("greeter"); // Works,but doesn't test my Greeter actor,but rather creates a generic TestActor (as I understand it)
var message = new Greeting("hello");
actor.Tell(message,TestActor);
ExpectMsg(message);
}
}
我也尝试将ExpectMsg行移动到actor.Tell行之上(因为在行动之前预期某事更有意义,而是验证之后的期望),但这也导致超时错误.
我已经尝试过NUnit和XUnit TestKits.
可能有一些我所忽视的真正的基础.
解决方法
TestKit用于进行更多的行为测试,以验证您的演员是否按照预期在整个演员系统的上下文中工作.这更像黑盒测试 – 你不直接到达演员的内部.相反,最好专注于给定信号A和演员行为B等行为,它应该向另一个演员D发出消息C.
在您的示例中,Greeter演员的问题是,它是静音的 – 虽然它可以接收到一些输入,但它不会在结果中做任何事情.从整个系统的角度来看,它可能会死亡,没有人会关心.
使用其他示例 – 给定以下演员：
public class Greeter : ReceiveActor
{
public Greeter()
{
Receive<Greet>(greet =>
{
// when message arrives,we publish it on the event stream
// and send response back to sender
Context.System.EventStream.Publish(greet.Who + " sends greetings");
Sender.Tell(new GreetBack(Self.Path.Name));
});
}
}
让我们创建一个示例测试规范：
public class GreeterSpec : TestKit
{
private IActorRef greeter;
public GreeterSpec() : base()
{
greeter = Sys.ActorOf<Greeter>("TestGreeter");
}
[Fact]
public void Greeter_should_GreetBack_when_Greeted()
{
// set test actor as message sender
greeter.Tell(new Greet("John Snow"),TestActor);
// ExpectMsg tracks messages received by TestActors
ExpectMsg<GreetBack>(msg => msg.Who == "TestGreeter");
}
[Fact]
public void Greeter_should_broadcast_incoming_greetings()
{
// create test probe and subscribe it to the event bus
var subscriber = CreateTestProbe();
Sys.EventStream.Subscribe(subscriber.Ref,typeof (string));
greeter.Tell(new Greet("John Snow"),TestActor);
// check if subscriber received a message
subscriber.ExpectMsg<string>("John Snow sends greetings");
}
}
你可以看到,这里我不检查演员的内部状态.相反,我正在观察它对我发送的信号的反应,并验证它是否是预期的结果.
