Persimmon の暫定的な assertSeqEquals を書いてみた

assertSeqEquals.fs

(*
 * The MIT License (MIT)
 *
 * Copyright (c) 2016 Kazuhiro Matsushima
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the
 * Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software,
 * and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR
 * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH
 * THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 *)

[<AutoOpen>]
module PersimmonExperimental =
    let assertSeqEquals (expected: seq<'T>) (actual: seq<'T>) =
        let eLen = Seq.length expected
        let aLen = Seq.length actual
        let violated message = AssertionResult.NotPassed(NotPassedCause.Violated message)
        if eLen <> aLen
        then violated <| sprintf "%A ≠ %A\nExpect: length is %d\nActual: length is %d" expected actual eLen aLen
        else
            let result =
                (expected, actual)
                ||> Seq.zip
                |> Seq.tryPick (fun (e, a) -> if e <> a then Some (e, a) else None)
            match result with
            | Some (e, a) ->
                violated <| sprintf "%A ≠ %A\nExpect: %A\nActual: %A" expected actual e a
            | None           -> AssertionResult.Passed()