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.Either (Either(..), either)
  17 import Data.Function (Fn2(), mkFn2)
  18 import Data.Maybe (Maybe(..), maybe)
  19 import Data.Nullable (toMaybe)
  20 import Data.String.Regex (Regex(), match, noFlags, regex)
  21
  22 import Unsafe.Coerce (unsafeCoerce)
  23
  24 import PursLoader.LoaderRef
  25   ( AsyncCallback()
  26   , LoaderRef()
  27   , Loader()
  28   , async
  29   , cacheable
  30   , clearDependencies
  31   , addDependency
  32   , resourcePath
  33   )
  34
  35 import PursLoader.Debug (debug)
  36 import PursLoader.Path (dirname, joinPath, relative)
  37 import PursLoader.Plugin as Plugin
  38
  39 type Effects eff = (loader :: Loader | eff)
  40
  41 loader :: forall eff. LoaderRef -> String -> Eff (Effects eff) Unit
  42 loader ref source = do
  43   callback <- async ref
  44
  45   cacheable ref
  46
  47   debug "Invoke PureScript plugin compilation"
  48
  49   pluginContext.compile (compile callback)
  50   where
  51   pluginContext :: Plugin.Context (Effects eff)
  52   pluginContext = (unsafeCoerce ref).purescriptWebpackPluginContext
  53
  54   compile :: AsyncCallback eff -> Plugin.Compile (Effects eff)
  55   compile callback error' { srcMap, ffiMap, graph } = do
  56     clearDependencies ref
  57
  58     either (const $ pure unit) (\a -> debug ("Adding PureScript dependency " ++ a)) name
  59
  60     addDependency ref (resourcePath ref)
  61
  62     either (\err -> callback (toMaybe error' <|> Just err) "") id
  63            (handle <$> name <*> dependencies <*> exports)
  64     where
  65     handle :: String -> Array String -> String -> Eff (Effects eff) Unit
  66     handle name' deps res = do
  67       debug ("Adding PureScript transitive dependencies for " ++ name')
  68       addTransitive name'
  69       foreachE deps addTransitive
  70       debug "Generated loader result"
  71       debug res
  72       callback (toMaybe error') res
  73
  74     exports :: Either Error String
  75     exports =
  76       if pluginContext.options.bundle
  77          then bundleExport <$> name
  78          else moduleExport <<< modulePath <$> name
  79       where
  80       bundleExport :: String -> String
  81       bundleExport name' = "module.exports = require('" ++ path ++ "')['" ++ name' ++ "'];"
  82         where
  83         path :: String
  84         path = relative resourceDir pluginContext.options.bundleOutput
  85
  86       moduleExport :: String -> String
  87       moduleExport path = "module.exports = require('" ++ path ++ "');"
  88
  89       modulePath :: String -> String
  90       modulePath = relative resourceDir <<< joinPath pluginContext.options.output
  91
  92       resourceDir :: String
  93       resourceDir = dirname (resourcePath ref)
  94
  95     dependencies :: Either Error (Array String)
  96     dependencies =
  97       if pluginContext.options.bundle
  98          then name >>= Plugin.dependenciesOf graph
  99          else pure []
 100
 101     addTransitive :: String -> Eff (Effects eff) Unit
 102     addTransitive dep = addDep (Plugin.get srcMap dep) *> addDep (Plugin.get ffiMap dep)
 103       where
 104       addDep :: Maybe String -> Eff (Effects eff) Unit
 105       addDep = maybe (pure unit) (addDependency ref)
 106
 107     name :: Either Error String
 108     name =
 109       maybe (Left $ error "Failed to parse module name") Right
 110             (join $ match re source >>= \as -> as !! 1)
 111       where
 112       re :: Regex
 113       re = regex "(?:^|\\n)module\\s+([\\w\\.]+)" noFlags { ignoreCase = true }
 114
 115 loaderFn :: forall eff. Fn2 LoaderRef String (Eff (Effects eff) Unit)
 116 loaderFn = mkFn2 loader