Persimmon の暫定的な assertSeqEquals を書いてみた

assertSeqEquals.fs

(*
 * The MIT License (MIT)
 *
 * Copyright (c) 2016 Kazuhiro Matsushima
 *
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[<AutoOpen>]
module Persimmon.Experimental

    open Persimmon

    let assertSeqEquals (expected: seq<'T>) (actual: seq<'T>) =
        let eLen = Seq.length expected
        let aLen = Seq.length actual
        let violated message = AssertionResult.NotPassed(None, 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()