Add collection constraints from NUnit

Description

I just wrote some tests and wanted to test a collection that has the equivalent item than another.

Could you please implement the collection constraints from NUnit?

Repro steps

I have to use NUnit’s function with like: let areCollectionsEqual = CollectionAssert.AreEquivalent([1;2;3], [3;1;2])

It’s not so “F#-ish”.

Known workarounds

I “extended” FsUnit with an extra function:

module FsUnit = 
  open NUnit.Framework.Constraints

  let equalsToCollection x = CollectionEquivalentConstraint x

So I can use this function like:

let areCollectionsEqual () = [1;2;3] |> should equalsToCollection [3;1;2]

Collection contraints implemented:

• equivalent
• supersetOf
• subsetOf

[CaptnCodr]

I would like to implement the subsetOf operator, too. To have the counterpart of supersetOf.

Like: [4;5] |> should be (subsetOf [1..10])

Is this okay?

[sergey-tihon]

I guess CollectionAssert.AreEqual case should be covered by equal operator due to structured equality

[1;2;3] |> should equal [1;2;3]

(we may add such test-cases and check)

for NUnit and MSTest is make sense to wrap CollectionAssert.AreEquivalent into equivalent operator. I am not sure about xUnit, we can leave it not implemented because it is not idiomatic for framework or reimplement logic from NUnit on our side