Seq.sequenceResultM returns seq (#159)

Author: TheAngryByrd

src/FsToolkit.ErrorHandling/Seq.fs

@@ -3,13 +3,13 @@ namespace FsToolkit.ErrorHandling
 [<RequireQualifiedAccess>]
 module Seq =
 
-    let sequenceResultM (xs: seq<Result<'t, 'e>>) : Result<'t list, 'e> =
+    let sequenceResultM (xs: seq<Result<'t, 'e>>) : Result<'t seq, 'e> =
         let rec loop xs ts =
             match Seq.tryHead xs with
             | Some x ->
                 x
                 |> Result.bind (fun t -> loop (Seq.tail xs) (t :: ts))
-            | None -> Ok(List.rev ts)
+            | None -> Ok(List.rev ts |> List.toSeq)
 
         // Seq.cache prevents double evaluation in Seq.tail
         loop (Seq.cache xs) []

tests/FsToolkit.ErrorHandling.Tests/Seq.fs

@@ -24,6 +24,7 @@ let sequenceResultMTests =
 
               let actual =
                   Seq.sequenceResultM (Seq.map Tweet.TryCreate tweets)
+                  |> Result.map Seq.toList
 
               Expect.equal actual expected "Should have an empty list of valid tweets"
 
@@ -34,6 +35,7 @@ let sequenceResultMTests =
 
               let actual =
                   Seq.sequenceResultM (Seq.map Tweet.TryCreate tweets)
+                  |> Result.map Seq.toList
 
               Expect.equal actual expected "Should have a list of valid tweets"