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xBehave Quickstart with computation builders

Another version of the xBahve quick start example, this time using custom F# computation builder to make the code nicer. We define a builder for step and custom functions for Given/And/When/Then.

SUT

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type Calculator () = member __.Add(x,y) = x + y

F# computation builder

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type StepBuilder(msg:string) = 
  member x.Zero() = ()
  member x.Delay(f) = f
  member x.Run(f) = msg.f(System.Action< >(f)) |> ignore

let Given what = StepBuilder("Given " + what)
let And what = StepBuilder("And " + what)
let When what = StepBuilder("When " + what)
let Then what = StepBuilder("Then " + what)

Sample scenario

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let [<Scenario>] addition() = 
  let x, y, calculator, answer = ref 0, ref 0, ref (Calculator()), ref 0
  Given "the number 1" { x := 1 }
  And "the number 2" { y := 2 }
  And "a calculator" { calculator := Calculator() }
  When "I add the numbers together" {
    answer := (!calculator).Add(!x, !y) }
  Then "the answer is 3" { Assert.Equal(3, !answer) }
Multiple items
type Calculator =
  new : unit -> Calculator
  member Add : x:int * y:int -> int

Full name: Script.Calculator

--------------------
new : unit -> Calculator
member Calculator.Add : x:int * y:int -> int

Full name: Script.Calculator.Add
val x : int
val y : int
Multiple items
type StepBuilder =
  new : msg:string -> StepBuilder
  member Delay : f:'b -> 'b
  member Run : f:'a -> unit
  member Zero : unit -> unit

Full name: Script.StepBuilder

--------------------
new : msg:string -> StepBuilder
val msg : string
Multiple items
val string : value:'T -> string

Full name: Microsoft.FSharp.Core.Operators.string

--------------------
type string = System.String

Full name: Microsoft.FSharp.Core.string
val x : StepBuilder
member StepBuilder.Zero : unit -> unit

Full name: Script.StepBuilder.Zero
member StepBuilder.Delay : f:'b -> 'b

Full name: Script.StepBuilder.Delay
val f : 'b
member StepBuilder.Run : f:'a -> unit

Full name: Script.StepBuilder.Run
val f : 'a
namespace System
Multiple items
type Action<'T1,'T2,'T3,'T4,'T5,'T6,'T7,'T8,'T9,'T10,'T11,'T12,'T13,'T14,'T15,'T16> =
  delegate of 'T1 * 'T2 * 'T3 * 'T4 * 'T5 * 'T6 * 'T7 * 'T8 * 'T9 * 'T10 * 'T11 * 'T12 * 'T13 * 'T14 * 'T15 * 'T16 -> unit

Full name: System.Action<_,_,_,_,_,_,_,_,_,_,_,_,_,_,_,_>

--------------------
type Action<'T1,'T2,'T3,'T4,'T5,'T6,'T7,'T8,'T9,'T10,'T11,'T12,'T13,'T14,'T15> =
  delegate of 'T1 * 'T2 * 'T3 * 'T4 * 'T5 * 'T6 * 'T7 * 'T8 * 'T9 * 'T10 * 'T11 * 'T12 * 'T13 * 'T14 * 'T15 -> unit

Full name: System.Action<_,_,_,_,_,_,_,_,_,_,_,_,_,_,_>

--------------------
type Action<'T1,'T2,'T3,'T4,'T5,'T6,'T7,'T8,'T9,'T10,'T11,'T12,'T13,'T14> =
  delegate of 'T1 * 'T2 * 'T3 * 'T4 * 'T5 * 'T6 * 'T7 * 'T8 * 'T9 * 'T10 * 'T11 * 'T12 * 'T13 * 'T14 -> unit

Full name: System.Action<_,_,_,_,_,_,_,_,_,_,_,_,_,_>

--------------------
type Action<'T1,'T2,'T3,'T4,'T5,'T6,'T7,'T8,'T9,'T10,'T11,'T12,'T13> =
  delegate of 'T1 * 'T2 * 'T3 * 'T4 * 'T5 * 'T6 * 'T7 * 'T8 * 'T9 * 'T10 * 'T11 * 'T12 * 'T13 -> unit

Full name: System.Action<_,_,_,_,_,_,_,_,_,_,_,_,_>

--------------------
type Action<'T1,'T2,'T3,'T4,'T5,'T6,'T7,'T8,'T9,'T10,'T11,'T12> =
  delegate of 'T1 * 'T2 * 'T3 * 'T4 * 'T5 * 'T6 * 'T7 * 'T8 * 'T9 * 'T10 * 'T11 * 'T12 -> unit

Full name: System.Action<_,_,_,_,_,_,_,_,_,_,_,_>

--------------------
type Action<'T1,'T2,'T3,'T4,'T5,'T6,'T7,'T8,'T9,'T10,'T11> =
  delegate of 'T1 * 'T2 * 'T3 * 'T4 * 'T5 * 'T6 * 'T7 * 'T8 * 'T9 * 'T10 * 'T11 -> unit

Full name: System.Action<_,_,_,_,_,_,_,_,_,_,_>

--------------------
type Action<'T1,'T2,'T3,'T4,'T5,'T6,'T7,'T8,'T9,'T10> =
  delegate of 'T1 * 'T2 * 'T3 * 'T4 * 'T5 * 'T6 * 'T7 * 'T8 * 'T9 * 'T10 -> unit

Full name: System.Action<_,_,_,_,_,_,_,_,_,_>

--------------------
type Action<'T1,'T2,'T3,'T4,'T5,'T6,'T7,'T8,'T9> =
  delegate of 'T1 * 'T2 * 'T3 * 'T4 * 'T5 * 'T6 * 'T7 * 'T8 * 'T9 -> unit

Full name: System.Action<_,_,_,_,_,_,_,_,_>

--------------------
type Action<'T1,'T2,'T3,'T4,'T5,'T6,'T7,'T8> =
  delegate of 'T1 * 'T2 * 'T3 * 'T4 * 'T5 * 'T6 * 'T7 * 'T8 -> unit

Full name: System.Action<_,_,_,_,_,_,_,_>

--------------------
type Action<'T1,'T2,'T3,'T4,'T5,'T6,'T7> =
  delegate of 'T1 * 'T2 * 'T3 * 'T4 * 'T5 * 'T6 * 'T7 -> unit

Full name: System.Action<_,_,_,_,_,_,_>

--------------------
type Action<'T1,'T2,'T3,'T4,'T5,'T6> =
  delegate of 'T1 * 'T2 * 'T3 * 'T4 * 'T5 * 'T6 -> unit

Full name: System.Action<_,_,_,_,_,_>

--------------------
type Action<'T1,'T2,'T3,'T4,'T5> =
  delegate of 'T1 * 'T2 * 'T3 * 'T4 * 'T5 -> unit

Full name: System.Action<_,_,_,_,_>

--------------------
type Action<'T1,'T2,'T3,'T4> =
  delegate of 'T1 * 'T2 * 'T3 * 'T4 -> unit

Full name: System.Action<_,_,_,_>

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type Action<'T1,'T2,'T3> =
  delegate of 'T1 * 'T2 * 'T3 -> unit

Full name: System.Action<_,_,_>

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type Action<'T1,'T2> =
  delegate of 'T1 * 'T2 -> unit

Full name: System.Action<_,_>

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type Action =
  delegate of unit -> unit

Full name: System.Action

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type Action<'T> =
  delegate of 'T -> unit

Full name: System.Action<_>
val ignore : value:'T -> unit

Full name: Microsoft.FSharp.Core.Operators.ignore
val Given : what:string -> StepBuilder

Full name: Script.Given
val what : string
val And : what:string -> StepBuilder

Full name: Script.And
val When : what:string -> StepBuilder

Full name: Script.When
val Then : what:string -> StepBuilder

Full name: Script.Then
val addition : unit -> unit

Full name: Script.addition
val x : int ref
val y : int ref
val calculator : Calculator ref
val answer : int ref
Multiple items
val ref : value:'T -> 'T ref

Full name: Microsoft.FSharp.Core.Operators.ref

--------------------
type 'T ref = Ref<'T>

Full name: Microsoft.FSharp.Core.ref<_>
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More information

Link:http://fssnip.net/kq
Posted:4 years ago
Author:Tomas Petricek
Tags: xunit , testing , bdd , xbehave