F#- How to use Assert.Multiple with F#

Question

I am running a few NUnit tests and want my each test case to run all assertions till the end of the block before quitting even if there are few assertion failures. I see that there is Assert.Multiple (https://github.com/nunit/docs/wiki/Multiple-Asserts) which can serve that purpose but I am getting an error:

No overloads match for method 'Multiple'. The available overloads are shown below. Possible overload: 'Assert.Multiple(testDelegate: TestDelegate) : unit'. Type constraint mismatch. The type 'unit' is not compatible with type 'TestDelegate' . Possible overload: 'Assert.Multiple(testDelegate: AsyncTestDelegate) : unit'. Type constraint mismatch. The type 'unit' is not compatible with type 'AsyncTestDelegate' . Done building target "CoreCompile" in project "NUnitTestProject1.fsproj" -- FAILED.

If I have my test like:

 [<Test>]
let getResponseCode () =
 let response = Request.createUrl Post "https://reqres.in/api/users"
 |> Request.setHeader (ContentType (ContentType.create("application", "json")))
 |> Request.bodyString """{ 
 "name": "morpheus",
 "job": "leader"}"""
 |> HttpFs.Client.getResponse
 |> run
 Assert.Multiple(() =>
 Assert.AreEqual(200,response.statusCode)
 Assert.AreEqual(215,response.contentLength)
 )

How should I write it so that it should not give me an error on using Assert.Multiple? Thanks in advance.

Check the screenshot of an error here:

Answer 1

You need to use a lambda in here. The syntax you've used there is the C# syntax for a lambda, in F# the syntax is fun () -> ..., so in your case it will look like

Assert.Multiple(fun () ->
 Assert.AreEqual(200, response.StatusCode)
 Assert.AreEqual(215, response.ContentLength)
)

• Sanjay Kumar: I gave a shot to this earlier but not sure why it didn't work then. Thanks working fine now :)