如何在f#中为模式匹配创建fsunit测试？

Question

我是f#和fsUnit的新手，我想知道如何使用fsUnit测试模式匹配语句。例如，如果我有以下代码，您将如何为其编写fsunit测试？

let Menu () = 
    let Choice = Console.ReadLine()

        match Choice with
        | "A" | "a" -> Function1()
        | "B" | "b" -> Function2()
        | "C" | "c" -> Function3()
        | _ ->  Printfn"Error"

Answer 1

首先，您应该将实现匹配逻辑的代码与读取输入的代码分开，因为您只能测试某些调用的结果是否正确：

let handleInput choice = 
    match choice with
    | "A" | "a" -> Function1()
    | "B" | "b" -> Function2()
    | "C" | "c" -> Function3()
    | _ ->  "Error"

let menu () = 
    let choice = Console.ReadLine()
    let output = handleInput choice
    printfn "%s" output

现在，您可以编写一系列测试来检查handleInput返回的字符串是否为您期望用于每个输入的字符串：

handleInput "A" |> should equal "whatever Function 1 returns"
handleInput "b" |> should equal "whatever Function 2 returns"
handleInput "D" |> should equal "Error"