Suave FAKE build watcher

build.fsx

// include Fake libs
#r "./packages/FAKE/tools/FakeLib.dll"

open Fake
open Fake.ProcessHelper

// Directories
[<Literal>]
let BuildDir  = "./build/"
[<Literal>]
let DeployDir = "./deploy/"

// version info
[<Literal>]
let Version = "0.1"  // or retrieve from CI server

// Filesets
let appReferences  =
    !! "/**/*.csproj"
    ++ "/**/*.fsproj"

let kill _ =
    do  Async.CancelDefaultToken ()
        killAllCreatedProcesses ()

let clean _ = do CleanDirs [BuildDir; DeployDir]

let build _ = 
    // compile all projects below src/app/
    MSBuildDebug BuildDir "Build" appReferences
    |> Log "AppBuild-Output: "

let run _ =
    do traceFAKE "About to run process. Press 'Q' to quit it once started."
    async {
        return! asyncShellExec {
            Program = BuildDir @@ "Main.exe"   // Change exe name.
            WorkingDirectory = __SOURCE_DIRECTORY__
            CommandLine = System.String.Empty
            Args = []
        }
    } |> Async.Ignore |> Async.Start

// Targets
do  Target "Clean" clean

    Target "Build" build

    Target "Deploy" (fun _ ->
        !! (BuildDir + "/**/*.*")
        -- "*.zip"
        |> Zip BuildDir (DeployDir + "ApplicationName." + Version + ".zip")
    )

    Target "Watch" (fun _ ->
        use watcher = !! "src/**/*.fs" |> WatchChanges (fun changes ->
            do  tracefn "%A" changes
                |> kill
//                |> clean
                |> build
                |> run
        )

        do  kill ()
            |> run

        let readChar () = (System.Console.ReadKey true).KeyChar
        let rec loop = function
            | 'q' | 'Q' -> do watcher.Dispose ()
            | _         -> loop (readChar ())

        readChar () |> loop
    )

// Build order
"Clean"
  ==> "Build"
  ==> "Watch" <=> "Deploy"

// start build
do RunTargetOrDefault "Build"