Question

我正在编写一个基本的UDP服务器，用于侦听给定端口上的消息，对输入进行一点按摩，并使用已处理的消息触发事件。我想编写测试，向服务器发送消息并验证是否引发了正确的事件。

服务器看起来像这样：

type UdpServer() =
    let messageReady = new Event<string>()

    member x.Start () = async {
            let rec loop () =                 
                let message = receiveMessage ()
                messageReceived.Trigger(message)
                return loop ()
            return! loop ()
        }

    member x.MessageReady = messageReady.Publish

我想写一个像这样的测试：

[<Test>]
let ``Should process message correctly`` () =
    let server = new UdpServer()
    server.Start() |> Async.Start
    sendMessageToServer "test message"

    // This will wait indefinitely since the message was already sent in the previous line
    let processedMessage = server.MessageReady |> Async.AwaitEvent |> Async.RunSynchronously
    processedMessage |> should be "expected output"

如何向服务器发送消息，然后测试是否已触发MessageReady事件是否正确？我可以使用mutable来存储值，但这看起来不像F＃方式：

let mutable processedMessage = ""
server.MessageReady |> Observable.subscribe(fun m -> processedMessage <- m)
sendMessageToServer "test message"
processedMessage |> should be "expected output"

Answer 1

使用observable和事件本质上是必要的，因此可以使用mutables / ref单元来检查它们是否被引发。

如何在IObservable上触发和测试事件？

1 个答案: