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