cycle.fs

module Tests

open System
open Xunit

let cycle inputs =
    let list = inputs |> Seq.skip 1
    let head = inputs |> Seq.head
    Seq.append list [head]

[<Fact>]
let ``A maps to B and B to A`` () =
    let given = ["A";"B"]
    let expected = ["B";"A"]
    let actual = given |> cycle
    Assert.Equal(expected, actual)

[<Fact>]
let ``A maps to B, B to C and C to A`` () =
    let given = ["A";"B";"C"]
    let expected = ["B";"C";"A"]
    let actual = given |> cycle
    Assert.Equal(expected, actual)

[<Fact>]
let ``A maps to B, B to C, C to D and D to A`` () =
    let given = ["A";"B";"C";"D"]
    let expected = ["B";"C";"D";"A"]
    let actual = given |> cycle
    Assert.Equal(expected, actual)