如何使用XUnit 2.0和FSharp样式测试捕获输出(How to capture output with XUnit 2.0 and FSharp style tests)

如何使用XUnit 2.0和FSharp样式测试捕获输出(How to capture output with XUnit 2.0 and FSharp style tests)

通常我使用F＃编写我的单元测试

open Swensen.Unquote open Xunit module MyTests = [<Fact>] let ``SomeFunction should return 10`` () = let a = SomeFunction() test <@ a = 10 @> [<Fact>] let ``SomeOtherFunction should return 11`` () = let a = SomeFunction() test <@ a = 11 @>

如果我想从xunit登录到控制台（根据http://xunit.github.io/docs/capturing-output.html ），需要编写一个构造函数，它需要一个ITestOutputHelper ，然后使用它来代替Console.WriteLine和家人。

using Xunit; using Xunit.Abstractions; public class MyTestClass { private readonly ITestOutputHelper output; public MyTestClass(ITestOutputHelper output) { this.output = output; } [Fact] public void MyTest() { var temp = "my class!"; output.WriteLine("This is output from {0}", temp); } }

但是fsharp模块是静态类，测试是静态方法。 没有构造函数来注入输出帮助器。

有没有一种方法可以访问当前测试的当前输出帮助器。 我知道我可以重写我的fsharp测试是非静态类，但这是不希望的。

看了XUnit的资料。

https://github.com/xunit/xunit/blob/e64f566b75f93cd3cec27f950759d82832bfe44b/src/xunit.execution/Sdk/Frameworks/Runners/TestClassRunner.cs#L90

我很确定这是一个被忽视的案例。 没有帮助者注入静态类。

Normally I write my unit tests in F# as

open Swensen.Unquote open Xunit module MyTests = [<Fact>] let ``SomeFunction should return 10`` () = let a = SomeFunction() test <@ a = 10 @> [<Fact>] let ``SomeOtherFunction should return 11`` () = let a = SomeFunction() test <@ a = 11 @>

If I wish to log to the console from xunit ( according to http://xunit.github.io/docs/capturing-output.html ) one needs to write a constructor that takes an ITestOutputHelper and then use that instead of Console.WriteLine and family.

using Xunit; using Xunit.Abstractions; public class MyTestClass { private readonly ITestOutputHelper output; public MyTestClass(ITestOutputHelper output) { this.output = output; } [Fact] public void MyTest() { var temp = "my class!"; output.WriteLine("This is output from {0}", temp); } }

however fsharp modules are static classes and the tests are static methods. There is no constructor to inject the output helper.

Is there a way to get access to the current output helper for the current test. I know I could rewrite my fsharp tests to be non static classes but that is undesired.

After looking at the XUnit source.

https://github.com/xunit/xunit/blob/e64f566b75f93cd3cec27f950759d82832bfe44b/src/xunit.execution/Sdk/Frameworks/Runners/TestClassRunner.cs#L90

I'm pretty sure this is an overlooked case. There is no injection of the helper into static classes.

最满意答案

如果xUnit没有用于注入参数的其他机制，那么我猜测唯一的选择是将测试定义为F＃对象类型中的方法。 我也更喜欢使用let编写测试作为函数，但下面的简单对象类型看起来不太糟糕：

open Swensen.Unquote open Xunit open Xunit.Abstractions type MyTests(output:ITestOutputHelper) = [<Fact>] member __.``SomeFunction should return 10`` () = let a = SomeFunction() output.WriteLine("Some function returned {0}", a) test <@ a = 10 @>

如果xUnit支持其他一些选项 - 我怀疑它们可能会对建议持开放态度，如果它不会太尴尬（可能使用方法参数？）

但除非xUnit增加对其他方法的支持，否则我认为您需要将F＃对象与方法一起使用。

If xUnit does not have any alternative mechanism for injection of the parameters, then I guess the only option is to define the tests as methods in an F# object type. I also prefer writing tests as functions using let, but the following simple object type does not look too bad:

open Swensen.Unquote open Xunit open Xunit.Abstractions type MyTests(output:ITestOutputHelper) = [<Fact>] member __.``SomeFunction should return 10`` () = let a = SomeFunction() output.WriteLine("Some function returned {0}", a) test <@ a = 10 @>

It would be nice if xUnit supported some other option for this - I suspect that they might be open to suggestions, if it is something that would not be too awkward (perhaps using a method parameter?)

But unless xUnit adds support for some other method, I think you'll need to use F# object with methods.