refactor: Split up Types.hs and logically organize modules (#1793)

src/PostgREST/Config/JSPath.hs

@@ -0,0 +1,59 @@
+{-|
+Module      : PostgREST.Types
+Description : PostgREST common types and functions used by the rest of the modules
+-}
+{-# LANGUAGE DuplicateRecordFields #-}
+
+module PostgREST.Config.JSPath
+  ( JSPath
+  , JSPathExp(..)
+  , pRoleClaimKey
+  ) where
+
+import qualified Text.ParserCombinators.Parsec as P
+
+import Data.Either.Combinators       (mapLeft)
+import Text.ParserCombinators.Parsec ((<?>))
+import Text.Read                     (read)
+
+import qualified GHC.Show (show)
+
+import Protolude      hiding (toS)
+import Protolude.Conv (toS)
+
+
+-- | full jspath, e.g. .property[0].attr.detail
+type JSPath = [JSPathExp]
+
+-- | jspath expression, e.g. .property, .property[0] or ."property-dash"
+data JSPathExp
+  = JSPKey Text
+  | JSPIdx Int
+
+instance Show JSPathExp where
+  -- TODO: this needs to be quoted properly for special chars
+  show (JSPKey k) = "." <> show k
+  show (JSPIdx i) = "[" <> show i <> "]"
+
+-- Used for the config value "role-claim-key"
+pRoleClaimKey :: Text -> Either Text JSPath
+pRoleClaimKey selStr =
+  mapLeft show $ P.parse pJSPath ("failed to parse role-claim-key value (" <> toS selStr <> ")") (toS selStr)
+
+pJSPath :: P.Parser JSPath
+pJSPath = toJSPath <$> (period *> pPath `P.sepBy` period <* P.eof)
+  where
+    toJSPath :: [(Text, Maybe Int)] -> JSPath
+    toJSPath = concatMap (\(key, idx) -> JSPKey key : maybeToList (JSPIdx <$> idx))
+    period = P.char '.' <?> "period (.)"
+    pPath :: P.Parser (Text, Maybe Int)
+    pPath = (,) <$> pJSPKey <*> P.optionMaybe pJSPIdx
+
+pJSPKey :: P.Parser Text
+pJSPKey = toS <$> P.many1 (P.alphaNum <|> P.oneOf "_$@") <|> pQuotedValue <?> "attribute name [a..z0..9_$@])"
+
+pJSPIdx :: P.Parser Int
+pJSPIdx = P.char '[' *> (read <$> P.many1 P.digit) <* P.char ']' <?> "array index [0..n]"
+
+pQuotedValue :: P.Parser Text
+pQuotedValue = toS <$> (P.char '"' *> P.many (P.noneOf "\"") <* P.char '"')