UX: updating to a newer version of Fantomas

[nojaf]

In #836, we introduced a whole new brave world of choosing your own Fantomas version.
These last weeks, we've published two new versions of Fantomas that are also compatible with Ionide.

The question remains, how do we want to inform the user of these updates?
We can easily detect new versions via the NuGet API:

#r "nuget: NuGet.Protocol"

open System
open System.Threading
open NuGet.Common
open NuGet.Versioning
open NuGet.Protocol
open NuGet.Protocol.Core.Types

type SemanticVersion with

    member this.Alpha: int option =
        if isNull this.Release then
            None
        else
            this.Release.Replace("alpha-", "")
            |> Int32.TryParse
            |> fun (success, alpha) -> if success then Some alpha else None

async {
    let logger = NullLogger.Instance
    let cancellationToken = CancellationToken.None

    let cache = new SourceCacheContext()

    let repository =
        Repository.Factory.GetCoreV3("https://api.nuget.org/v3/index.json")

    let! resource =
        repository.GetResourceAsync<FindPackageByIdResource>()
        |> Async.AwaitTask

    let! versions =
        resource.GetAllVersionsAsync(
            "fantomas-tool",
            cache,
            logger,

            cancellationToken
        )
        |> Async.AwaitTask

    versions
    |> Seq.filter (fun v ->
        v.Major = 4
        && v.Minor = 6
        && (Option.map (fun alpha -> alpha >= 4) v.Alpha
            |> Option.defaultValue true)
    )
    |> Seq.iter (fun v -> printfn "%A" v.Release)
}
|> Async.RunSynchronously

But how do we want to deal with this?
Some people will be interested in every version (alpha, beta, stable), while others will only care for revisions or minors.

[baronfel]

In an ideal world, I think the user should be prompted:

• once per repo
• per stable version only
• with an option to ignore the version specified

all of this is stuff that would probably live at the ionide/FSAC layers and not necessarily in the Fantomas.Client library itself (aside from maybe exposing an API to check the current version and query for the latest Fantomas version specifically), and might be conditioned behind a config flag like fsharp.fantomas.updateCheck: true|major|minor|patch|prerelease|ignore or something.

[nojaf]

Yup, I have no intention of putting anything in Fantomas.Client for this.
There is an API though to get the current version of an F# file.