Timeout async guard inappropriately triggers with F#

[bradwilson]

Reported here: #2222 (comment)

Sample code that fails to run with 2.7.0:

module Tests

open System.Threading.Tasks
open Xunit

[<Fact(Timeout = 3000)>]
let TestMethod() =
    task {
        Task.Delay(10) |> Async.AwaitTask |> ignore
        Assert.Fail("Make sure things waited")
    }

Adding :> Task cast to the end of the task lambda is a temporary workaround:

module Tests

open System.Threading.Tasks
open Xunit

[<Fact(Timeout = 3000)>]
let TestMethod() =
    task {
        Task.Delay(10) |> Async.AwaitTask |> ignore
        Assert.Fail("Make sure things waited")
    } :> Task

[bradwilson]

The "culprit" here is the new task keyword, which I wasn't familiar with. Instead of returning an FSharpAsync<T>, it returns Task<T>, presumably for better cross-language interop.

[bradwilson]

Available in v2 2.7.1-pre.7
Available in v3 0.1.1-pre.378

https://xunit.net/docs/using-ci-builds