FSharp.xUnit 1.2.2

The class library extends xunit to assert equal.

• It output data in F# style.

• It's easier to customize the IEqualityComparer.

install

Install-Package FSharp.xUnit

GetStarted

使用系统默认的相等比较器：

open FSharp.xUnit

[<Fact>]
let ``My test`` () =
    Should.equal 1 1

相反的操作Should.notEqual

使用自定义的相等比较器，先配置比较器，newtonsoft.net是.net流行的json库，但是JProperty缺少结构化比较的方法，这个代码示例演示如何定义适配器：

let tryGetJProperty (ty: Type) =
    if ty = typeof<JProperty> then
        Some(fun (loop:Type -> IEqualityComparer) -> 
            let stringComparer = loop typeof<string>
            let jTokenEqualityComparer = JTokenEqualityComparer()
            {
                new IEqualityComparer with
                    member this.Equals(p1,p2) =
                        let p1 = unbox<JProperty> p1
                        let p2 = unbox<JProperty> p2
                        stringComparer.Equals(p1.Name, p2.Name) && jTokenEqualityComparer.Equals(p1.Value, p2.Value)
                    member this.GetHashCode(p) = 
                        let p = unbox<JProperty> p
                        hash [|stringComparer.GetHashCode p.Name; jTokenEqualityComparer.GetHashCode p.Value|]
            })
    else None
    
let tryGetJToken  (ty: Type) =
    if typeof<JToken>.IsAssignableFrom ty then
        Some(fun (loop:Type -> IEqualityComparer) -> 
            let genericComp = JTokenEqualityComparer()
            {
                new IEqualityComparer with
                    member this.Equals(p1,p2) = genericComp.Equals(unbox<JToken> p1,unbox<JToken> p2)
                    member this.GetHashCode(p) = 
                        genericComp.GetHashCode(unbox<JToken> p)
            })
    else None

let should = EqualConfig.``override``[ 
    tryGetJProperty
    tryGetJToken
    ]

注意派生类要放到基类的上面，否则派生类数据就会进到基类适配器，派生类适配器被旁路掉了。

获得了should，我们就可以进行自定义的测试了，测试的方法和上面的差不多：

[<Fact>]
member this.``translateFields``() =
    let y = [JProperty("b",JValue(null:obj));JProperty("a",JValue(0.0))]
    let z = [JProperty("b",JValue(null:obj));JProperty("a",JValue(0.0))]
    should.equal y z

相反的操作should.notEqual