F# 在FsUnit';中,我如何可以忽略有区别的联合案例的值;谁断言?
我怎么能在FsUnit的断言中忽略一个有区别的联合案例的值呢 例如:F# 在FsUnit';中,我如何可以忽略有区别的联合案例的值;谁断言?,f#,fsunit,F#,Fsunit,我怎么能在FsUnit的断言中忽略一个有区别的联合案例的值呢 例如: type TransactionAttempt = { Deposited:float Requires:float } type RequestResult = | Denied of TransactionAttempt | Granted of Product 在我的测试中,我想这样做: let display = balance |> select Pepsi displa
type TransactionAttempt = {
Deposited:float
Requires:float
}
type RequestResult =
| Denied of TransactionAttempt
| Granted of Product
在我的测试中,我想这样做:
let display = balance |> select Pepsi
display |> should equal Denied
display |> should equal (Denied {Deposited=0.25; Requires=1.00})
我不介意这样做:
display |> should equal (Denied _)
然而,我不得不这样做:
let display = balance |> select Pepsi
display |> should equal Denied
display |> should equal (Denied {Deposited=0.25; Requires=1.00})
请注意,我对上述表达式的理解必须非常明确。
因此,我只想知道它是否被拒绝。我不在乎细节
以下是实际测试:
[<Test>]
let ``Vending machine reflects more money required for selection``() =
// Setup
let balance = Quarter |> insert []
// Test
let display = balance |> select Pepsi
// Verify
display |> should equal (Denied {Deposited=0.25; Requires=1.00})
以下是整个域:
module Machine
type Deposit =
| Nickel
| Dime
| Quarter
| OneDollarBill
| FiveDollarBill
type TransactionAttempt = {
Deposited:float
Requires:float
}
type State =
| OutOfService
| PaymentReceived of Deposit
| WaitingForSelection
| NotPaidInFull of TransactionAttempt
type Product =
| Pepsi
| Coke
| Sprite
| MountainDew
type RequestResult =
| Denied of TransactionAttempt
| Granted of Product
(* Functions *)
open System
let display = function
| OutOfService -> "Out of Service"
| WaitingForSelection -> "Make selection"
| NotPaidInFull attempt -> sprintf "%s Required" ((attempt.Requires - attempt.Deposited).ToString("C2"))
| PaymentReceived deposit -> match deposit with
| Nickel -> "5¢"
| Dime -> "10¢"
| Quarter -> "25¢"
| OneDollarBill -> "$1.00"
| FiveDollarBill -> "$5.00"
let getBalance coins =
coins |> List.fold (fun acc d -> match d with
| Nickel -> acc + 0.05
| Dime -> acc + 0.10
| Quarter -> acc + 0.25
| OneDollarBill -> acc + 1.00
| FiveDollarBill -> acc + 5.00) 0.00
let insert balance coin =
coin::balance |> getBalance
let getPrice = function
| Pepsi -> 1.00
| Coke -> 1.00
| Sprite -> 1.00
| MountainDew -> 1.00
let select product balance =
let attempt = { Deposited=balance
Requires=product |> getPrice }
let paidInFull = attempt.Deposited >= attempt.Requires
if not paidInFull then
Denied attempt
else Granted product
我能想到的最简单的方法是为您想要的支票编写一个谓词:
let isDenied du =
match du with
| Denied _ -> true
| _ -> false
或者,由于让f x=将x与…
匹配等同于让f=函数…
,这可能是:
let isDenied = function Denied _ -> true | _ -> false
然后,您的测试如下所示:
display |> isDenied |> should be True
请注意,True
,带大写字母T,是一个约束条件。如果与布尔值进行比较,那么
display |> isDenied |> should equal true
如果您发现必须编写大量这些自定义谓词,那么可能有一种更通用的解决方案,包括为NUnit或XUnit或您在后端使用的任何测试框架编写自定义约束。但是作为F#的相对新手,您可能应该首先使用简单的解决方案,然后对其进行推广
另外,如果您决定编写自定义约束,请查看(如果您使用的是NUnit)或(如果您使用的是XUnit)以获得灵感。由@rmunn给出的答案看起来不错,但是
display |>的错误应该是相同的(拒绝{deposition=0.25;Requires=1.00}
?应该拒绝{deposition=0.22;Requires=1.04}
通过测试吗?谢谢。你说得对。