Install GHCJS for Stack

install-ghcjs-for-stack.hs

#!/usr/bin/env stack
-- stack --install-ghc runghc --package turtle --package wreq

{-# LANGUAGE OverloadedStrings #-}

import qualified Control.Foldl as Fold
import Control.Lens ((^.))
import Control.Monad (when)
import Data.ByteString.Lazy (hPut)
import Data.Maybe (fromMaybe)
import qualified Data.Text as T
import Data.Time.Format (formatTime, defaultTimeLocale)
import Network.Wreq (get, responseBody)
import Turtle


main = do
  dateStr <- T.pack . formatTime defaultTimeLocale "%Y%m%d" <$> date

  let url = "http://ghcjs.luite.com/master-"<>dateStr<>".tar.gz"
  echo $ format ("Downloading "%s%"...") url
  r <- get (T.unpack url)

  let tempdir = "temp-ghcjs-archive"
  echo $ format ("Using temp directory: "%fp) tempdir
  alreadyThere <- testdir tempdir
  when alreadyThere $ rmtree tempdir
  mkdir tempdir

  let tempfile = tempdir</>"archive.tar.gz"
  echo $ format ("Writing to "%fp%"...") tempfile
  with (writeonly tempfile) $ \temphandle->
    hPut temphandle (r ^. responseBody)

  echo "Unpacking..."
  proc "tar" ["-xzf", format fp tempfile, format ("-C"%fp) tempdir] empty
    .||. die "failed to unpack archive"

  Just ghcjsDir <- fold
    (ls tempdir)
    (Fold.find (T.isPrefixOf "ghcjs-" . format fp . filename))

  let newFolderName = ghcjsDir <.> dateStr
  let ghcjsStackVersion = format (fp%"_ghc-7.10.2") (filename newFolderName)
  let outputArchive = tempdir </> fromText ghcjsStackVersion <.> "tar.gz"

  mv ghcjsDir newFolderName
  echo $ format ("Archiving to "%fp) outputArchive

  targzPack (parent newFolderName) (filename newFolderName) outputArchive

  -- Install archive to the approprate stack folder
  Just outDir <- fold (inproc "stack" ["path", "--ghc-paths"] empty) Fold.head
  echo $ format ("Copying to "%s) outDir
  cp outputArchive (fromText outDir </> filename outputArchive)

  echo $ format ("DONE: Add 'compiler: "%s%"' or 'resolver: "%s%"' to your stack.yaml and run 'stack setup' to boot it.")
                ghcjsStackVersion ghcjsStackVersion

targzPack inDir inFile outFilePath =
    proc "tar" ["-czf", format fp outFilePath, format ("-C"%fp) inDir, format fp inFile] empty
      .||. die (format ("failed to create archive: "%fp) outFilePath)

Wow...apparently GitHub doesn't notify me when people comment on this. :/

@yamafaktory: Yes, apparently newer versions of stack don't play as nicely with this. I've found it still works but you must "fake" out stack by filling in the whole setup-info thing:

So for today's build, I would run the script and then add this to my .cabal file:

compiler: ghcjs-0.2.0.20160107_ghc-7.10.2
compiler-check: match-exact
setup-info:
  ghcjs:
      source:
            ghcjs-0.2.0.20160107_ghc-7.10.2:
                    url: "http://ghcjs.luite.com/master-20160107.tar.gz"

@mgsloan: I'd be much happier if stack didn't care about the folder name!

@mgsloan: @yamafaktory: Yay! This script will soon be obsolete! commercialhaskell/stack#1622

Note that this script is still handy if you want your ghcjs version to include the date.