src/PursLoader/Loader.purs

   1 module PursLoader.Loader
   2   ( Effects()
   3   , loader
   4   , loaderFn
   5   ) where
   6
   7 import Prelude (Unit(), ($), (>>=), (<$>), (<*>), (++), bind, const, id, pure, unit)
   8
   9 import Control.Apply ((*>))
  10 import Control.Bind (join)
  11 import Control.Monad.Eff (Eff(), foreachE)
  12 import Control.Monad.Eff.Exception (Error(), error)
  13
  14 import Data.Array ((!!))
  15 import Data.Bifunctor (lmap)
  16 import Data.Either (Either(..), either)
  17 import Data.Foreign.Class (read)
  18 import Data.Function (Fn2(), mkFn2)
  19 import Data.Maybe (Maybe(..), maybe)
  20 import Data.Nullable (toMaybe)
  21 import Data.String.Regex (Regex(), match, noFlags, regex)
  22
  23 import Unsafe.Coerce (unsafeCoerce)
  24
  25 import PursLoader.LoaderRef
  26   ( AsyncCallback()
  27   , LoaderRef()
  28   , Loader()
  29   , async
  30   , cacheable
  31   , query
  32   , clearDependencies
  33   , addDependency
  34   , resourcePath
  35   )
  36
  37 import PursLoader.Debug (debug)
  38 import PursLoader.LoaderUtil (parseQuery)
  39 import PursLoader.Options (Options(..))
  40 import PursLoader.Path (dirname, relative)
  41 import PursLoader.Plugin as Plugin
  42
  43 type Effects eff = (loader :: Loader | eff)
  44
  45 loader :: forall eff. LoaderRef -> String -> Eff (Effects eff) Unit
  46 loader ref source = do
  47   callback <- async ref
  48
  49   cacheable ref
  50
  51   debug "Invoke PureScript plugin compilation"
  52
  53   pluginContext.compile (compile callback)
  54   where
  55   pluginContext :: Plugin.Context (Effects eff)
  56   pluginContext = (unsafeCoerce ref).purescriptWebpackPluginContext
  57
  58   compile :: AsyncCallback eff -> Plugin.Compile (Effects eff)
  59   compile callback error' { srcMap, ffiMap, graph } = do
  60     clearDependencies ref
  61
  62     either (const $ pure unit) (\a -> debug ("Adding PureScript dependency " ++ a)) name
  63
  64     addDependency ref (resourcePath ref)
  65
  66     either (\err -> callback (Just err) "") id
  67            (handle <$> name <*> dependencies <*> exports)
  68     where
  69     handle :: String -> Array String -> String -> Eff (Effects eff) Unit
  70     handle name' deps res = do
  71       debug ("Adding PureScript transitive dependencies for " ++ name')
  72       addTransitive name'
  73       foreachE deps addTransitive
  74       debug "Generated loader result"
  75       debug res
  76       callback (toMaybe error') res
  77
  78     exports :: Either Error String
  79     exports = (\a b -> "module.exports = require('" ++ a ++ "')['" ++ b ++ "'];") <$> path <*> name
  80
  81     dependencies :: Either Error (Array String)
  82     dependencies = name >>= Plugin.dependenciesOf graph
  83
  84     addTransitive :: String -> Eff (Effects eff) Unit
  85     addTransitive dep = addDep (Plugin.get srcMap dep) *> addDep (Plugin.get ffiMap dep)
  86       where
  87       addDep :: Maybe String -> Eff (Effects eff) Unit
  88       addDep = maybe (pure unit) (addDependency ref)
  89
  90     name :: Either Error String
  91     name =
  92       maybe (Left $ error "Failed to parse module name") Right
  93             (join $ match re source >>= \as -> as !! 1)
  94       where
  95       re :: Regex
  96       re = regex "(?:^|\\n)module\\s+([\\w\\.]+)" noFlags { ignoreCase = true }
  97
  98     path :: Either Error String
  99     path = (\(Options opts) -> relative resourceDir opts.bundleOutput) <$> options
 100       where
 101       options :: Either Error Options
 102       options =
 103         lmap (const $ error "Failed to parse loader query")
 104              (read $ parseQuery (query ref))
 105
 106       resourceDir :: String
 107       resourceDir = dirname (resourcePath ref)
 108
 109 loaderFn :: forall eff. Fn2 LoaderRef String (Eff (Effects eff) Unit)
 110 loaderFn = mkFn2 loader