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 <$> name <*> dependencies <*> exports)
  68     where
  69     handle :: String -> Array String -> String -> Eff (Effects eff) Unit
  70     handle name' deps res = do
  71       debug ("Adding PureScript transitive dependencies for " ++ name')
  72       addTransitive name'
  73       foreachE deps addTransitive
  74       callback (toMaybe error') res
  75
  76     exports :: Either Error String
  77     exports = (\a b -> "module.exports = require('" ++ a ++ "')['" ++ b ++ "'];") <$> path <*> name
  78
  79     dependencies :: Either Error (Array String)
  80     dependencies = name >>= Plugin.dependenciesOf graph
  81
  82     addTransitive :: String -> Eff (Effects eff) Unit
  83     addTransitive dep = addDep (Plugin.get srcMap dep) *> addDep (Plugin.get ffiMap dep)
  84       where
  85       addDep :: Maybe String -> Eff (Effects eff) Unit
  86       addDep = maybe (pure unit) (addDependency ref)
  87
  88     name :: Either Error String
  89     name =
  90       maybe (Left $ error "Failed to parse module name") Right
  91             (join $ match re source >>= \as -> as !! 1)
  92       where
  93       re :: Regex
  94       re = regex "(?:^|\\n)module\\s+([\\w\\.]+)" noFlags { ignoreCase = true }
  95
  96     path :: Either Error String
  97     path = (\(Options opts) -> relative resourceDir opts.bundleOutput) <$> options
  98       where
  99       options :: Either Error Options
 100       options =
 101         lmap (const $ error "Failed to parse loader query")
 102              (read $ parseQuery (query ref))
 103
 104       resourceDir :: String
 105       resourceDir = dirname (resourcePath ref)
 106
 107 loaderFn :: forall eff. Fn2 LoaderRef String (Eff (Effects eff) Unit)
 108 loaderFn = mkFn2 loader