refactor: App.hs and related changes (#1725)

* Use ExceptT to avoid 'staircasing' case analysis in App.hs * Split large function in App.hs into individual handler functions * Adapt API of Auth.hs, OpenApi.hs etc. to simplify the use of those modules in App.hs * Split optional rollback functionality into Middleware * Unify SimpleError and ApiRequestError into one Error type, so it can be used across modules
2021-02-23 22:41:48 +01:00
parent 0ddd676ef0
commit e6973f966b
11 changed files with 734 additions and 567 deletions
@@ -81,6 +81,7 @@ library
                    , jose                      >= 0.8.1 && < 0.9
                    , lens                      >= 4.14 && < 4.20
                    , lens-aeson                >= 1.0.1 && < 1.2
+                    , mtl                       >= 2.2.2 && < 2.3
                    , network-uri               >= 2.6.1 && < 2.8
                    , optparse-applicative      >= 0.13 && < 0.17
                    , parsec                    >= 3.1.11 && < 3.2
@@ -9,430 +9,547 @@ Some of its functionality includes:
 - Producing HTTP Headers according to RFCs.
 - Content Negotiation
 -}
-{-# LANGUAGE FlexibleContexts    #-}
-{-# LANGUAGE MultiWayIf          #-}
-{-# LANGUAGE NamedFieldPuns      #-}
-{-# LANGUAGE ScopedTypeVariables #-}
+{-# LANGUAGE RecordWildCards #-}
+module PostgREST.App (postgrest) where

-module PostgREST.App (
-  postgrest
-) where
+import Control.Monad.Except    (liftEither)
+import Data.Either.Combinators (mapLeft)
+import Data.IORef              (IORef, readIORef)
+import Data.List               (union)
+import Data.Time.Clock         (UTCTime)

-import qualified Data.ByteString.Char8      as BS
-import qualified Data.HashMap.Strict        as M
-import qualified Data.List                  as L (union)
-import qualified Data.Set                   as S
-import qualified Hasql.Pool                 as P
-import qualified Hasql.Transaction          as H
-import qualified Hasql.Transaction          as HT
-import qualified Hasql.Transaction.Sessions as HT
+import qualified Data.ByteString.Char8           as BS8
+import qualified Data.ByteString.Lazy            as LBS
+import qualified Data.Set                        as Set
+import qualified Hasql.DynamicStatements.Snippet as SQL
+import qualified Hasql.Pool                      as SQL
+import qualified Hasql.Transaction               as SQL
+import qualified Hasql.Transaction.Sessions      as SQL
+import qualified Network.HTTP.Types.Header       as HTTP
+import qualified Network.HTTP.Types.Status       as HTTP
+import qualified Network.HTTP.Types.URI          as HTTP
+import qualified Network.Wai                     as Wai

-import Data.IORef             (IORef, readIORef)
-import Data.Time.Clock        (UTCTime)
-import Network.HTTP.Types.URI (renderSimpleQuery)
+import qualified PostgREST.ApiRequest       as ApiRequest
+import qualified PostgREST.Auth             as Auth
+import qualified PostgREST.DbRequestBuilder as ReqBuilder
+import qualified PostgREST.DbStructure      as DbStructure
+import qualified PostgREST.Error            as Error
+import qualified PostgREST.Middleware       as Middleware
+import qualified PostgREST.OpenAPI          as OpenAPI
+import qualified PostgREST.QueryBuilder     as QueryBuilder
+import qualified PostgREST.RangeQuery       as RangeQuery
+import qualified PostgREST.Statements       as Statements

-import Control.Applicative
-import Data.Maybe
-import Network.HTTP.Types.Header
-import Network.HTTP.Types.Status
-import Network.Wai
+import PostgREST.ApiRequest (Action (..), ApiRequest (..),
+                             InvokeMethod (..), Target (..))
+import PostgREST.Config     (AppConfig (..))
+import PostgREST.Error      (Error)

-import PostgREST.ApiRequest       (Action (..), ApiRequest (..),
-                                   InvokeMethod (..), Target (..),
-                                   mutuallyAgreeable, userApiRequest)
-import PostgREST.Auth             (attemptJwtClaims, containsRole,
-                                   jwtClaims)
-import PostgREST.Config           (AppConfig (..))
-import PostgREST.DbRequestBuilder (mutateRequest, readRequest,
-                                   returningCols)
-import PostgREST.DbStructure
-import PostgREST.Error            (PgError (..), SimpleError (..),
-                                   errorResponseFor, singularityError)
-import PostgREST.Middleware
-import PostgREST.OpenAPI
-import PostgREST.QueryBuilder     (limitedQuery, mutateRequestToQuery,
-                                   readRequestToCountQuery,
-                                   readRequestToQuery,
-                                   requestToCallProcQuery)
-import PostgREST.RangeQuery       (allRange, contentRangeH,
-                                   rangeStatusHeader)
-import PostgREST.Statements       (callProcStatement,
-                                   createExplainStatement,
-                                   createReadStatement,
-                                   createWriteStatement)
 import PostgREST.Types
-import Protolude                  hiding (Proxy, intercalate, toS)
-import Protolude.Conv             (toS)

-postgrest :: LogLevel -> IORef AppConfig -> IORef (Maybe DbStructure) -> P.Pool -> IO UTCTime -> IO () -> Application
+import Protolude      hiding (Handler, toS)
+import Protolude.Conv (toS)
+
+
+data RequestContext = RequestContext
+  { ctxConfig      :: AppConfig
+  , ctxDbStructure :: DbStructure
+  , ctxApiRequest  :: ApiRequest
+  , ctxContentType :: ContentType
+  }
+
+type Handler = ExceptT Error
+
+type DbHandler = Handler SQL.Transaction
+
+
+-- | PostgREST application
+postgrest
+  :: LogLevel
+  -> IORef AppConfig
+  -> IORef (Maybe DbStructure)
+  -> SQL.Pool
+  -> IO UTCTime
+  -> IO () -- ^ Lauch connection worker in a separate thread
+  -> Wai.Application
 postgrest logLev refConf refDbStructure pool getTime connWorker =
-  pgrstMiddleware logLev $ \ req respond -> do
-    time <- getTime
-    body <- strictRequestBody req
-    maybeDbStructure <- readIORef refDbStructure
-    conf <- readIORef refConf
+  Middleware.pgrstMiddleware logLev $
+    \req respond -> do
+      time <- getTime
+      conf <- readIORef refConf
+      maybeDbStructure <- readIORef refDbStructure
+
+      let
+        eitherResponse :: IO (Either Error Wai.Response)
+        eitherResponse =
+          runExceptT $ postgrestResponse conf maybeDbStructure pool time req
+
+      response <- either Error.errorResponseFor identity <$> eitherResponse
+
+      -- Launch the connWorker when the connection is down.  The postgrest
+      -- function can respond successfully (with a stale schema cache) before
+      -- the connWorker is done.
+      when (Wai.responseStatus response == HTTP.status503) connWorker
+
+      respond response
+
+postgrestResponse
+  :: AppConfig
+  -> Maybe DbStructure
+  -> SQL.Pool
+  -> UTCTime
+  -> Wai.Request
+  -> Handler IO Wai.Response
+postgrestResponse conf@AppConfig{..} maybeDbStructure pool time req = do
+  body <- lift $ Wai.strictRequestBody req
+
+  dbStructure <-
    case maybeDbStructure of
-      Nothing -> respond . errorResponseFor $ ConnectionLostError
-      Just dbStructure -> do
-        response <- do
-          let apiReq = userApiRequest (configDbSchemas conf) (configDbRootSpec conf) dbStructure req body
-          case apiReq of
-            Left err -> return . errorResponseFor $ err
-            Right apiRequest -> do
-              -- The jwt must be checked before touching the db.
-              attempt <- attemptJwtClaims (configJWKS conf) (configJwtAudience conf) (toS $ iJWT apiRequest) time (configJwtRoleClaimKey conf)
-              case jwtClaims attempt of
-                Left errJwt -> return . errorResponseFor $ errJwt
-                Right claims -> do
-                  let
-                    authed = containsRole claims
-                    shouldCommit   = configDbTxAllowOverride conf && iPreferTransaction apiRequest == Just Commit
-                    shouldRollback = configDbTxAllowOverride conf && iPreferTransaction apiRequest == Just Rollback
-                    preferenceApplied
-                      | shouldCommit    = addHeadersIfNotIncluded [(hPreferenceApplied, BS.pack (show Commit))]
-                      | shouldRollback  = addHeadersIfNotIncluded [(hPreferenceApplied, BS.pack (show Rollback))]
-                      | otherwise       = identity
-                    handleReq = do
-                      when (shouldRollback || (configDbTxRollbackAll conf && not shouldCommit)) HT.condemn
-                      mapResponseHeaders preferenceApplied <$> runPgLocals conf claims (app dbStructure conf) apiRequest
-                  dbResp <- P.use pool $ HT.transaction HT.ReadCommitted (txMode apiRequest) handleReq
-                  return $ either (errorResponseFor . PgError authed) identity dbResp
-        -- Launch the connWorker when the connection is down. The postgrest function can respond successfully(with a stale schema cache) before the connWorker is done.
-        when (responseStatus response == status503) connWorker
-        respond response
+      Just dbStructure ->
+        return dbStructure
+      Nothing ->
+        throwError Error.ConnectionLostError

-txMode :: ApiRequest -> HT.Mode
-txMode apiRequest =
-  case (iAction apiRequest, iTarget apiRequest) of
-    (ActionRead _        , _) -> HT.Read
-    (ActionInfo          , _) -> HT.Read
-    (ActionInspect _     , _) -> HT.Read
-    (ActionInvoke InvGet , _) -> HT.Read
-    (ActionInvoke InvHead, _) -> HT.Read
-    (ActionInvoke InvPost, TargetProc ProcDescription{pdVolatility=Stable} _)    -> HT.Read
-    (ActionInvoke InvPost, TargetProc ProcDescription{pdVolatility=Immutable} _) -> HT.Read
-    _ -> HT.Write
+  apiRequest@ApiRequest{..} <-
+    liftEither . mapLeft Error.ApiRequestError $
+      ApiRequest.userApiRequest configDbSchemas configDbRootSpec dbStructure req body

-app :: DbStructure -> AppConfig -> ApiRequest -> H.Transaction Response
-app dbStructure conf apiRequest =
-  let rawContentTypes = (decodeContentType <$> configRawMediaTypes conf) `L.union` [ CTOctetStream, CTTextPlain ] in
-  case responseContentTypeOrError (iAccepts apiRequest) rawContentTypes (iAction apiRequest) (iTarget apiRequest) of
-    Left errorResponse -> return errorResponse
-    Right contentType ->
-      case (iAction apiRequest, iTarget apiRequest) of
+  -- The JWT must be checked before touching the db
+  jwtClaims <- Auth.jwtClaims conf (toS iJWT) time

-        (ActionRead headersOnly, TargetIdent (QualifiedIdentifier tSchema tName)) ->
-          case readSqlParts tSchema tName of
-            Left errorResponse -> return errorResponse
-            Right (q, cq, bField, _) -> do
-              let cQuery = if estimatedCount
-                             then limitedQuery cq ((+ 1) <$> maxRows) -- LIMIT maxRows + 1 so we can determine below that maxRows was surpassed
-                             else cq
-                  stm = createReadStatement q cQuery (contentType == CTSingularJSON) shouldCount
-                        (contentType == CTTextCSV) bField pgVer prepared
-                  explStm = createExplainStatement cq prepared
-              row <- H.statement mempty stm
-              let (tableTotal, queryTotal, _ , body, gucHeaders, gucStatus) = row
-                  gucs =  (,) <$> gucHeaders <*> gucStatus
-              case gucs of
-                Left err -> return $ errorResponseFor err
-                Right (ghdrs, gstatus) -> do
-                  total <- if | plannedCount   -> H.statement mempty explStm
-                              | estimatedCount -> if tableTotal > (fromIntegral <$> maxRows)
-                                                    then do estTotal <- H.statement mempty explStm
-                                                            pure $ if estTotal > tableTotal then estTotal else tableTotal
-                                                    else pure tableTotal
-                              | otherwise      -> pure tableTotal
-                  let (rangeStatus, contentRange) = rangeStatusHeader topLevelRange queryTotal total
-                      status = fromMaybe rangeStatus gstatus
-                      headers = addHeadersIfNotIncluded (catMaybes [
-                                  Just $ toHeader contentType, Just contentRange,
-                                  Just $ contentLocationH tName (iCanonicalQS apiRequest), profileH])
-                                (unwrapGucHeader <$> ghdrs)
-                      rBody = if headersOnly then mempty else toS body
-                  return $
-                    if contentType == CTSingularJSON && queryTotal /= 1
-                      then errorResponseFor . singularityError $ queryTotal
-                      else responseLBS status headers rBody
+  contentType <-
+    case ApiRequest.mutuallyAgreeable (requestContentTypes conf apiRequest) iAccepts of
+      Just ct ->
+        return ct
+      Nothing ->
+        throwError . Error.ContentTypeError $ map toMime iAccepts

-        (ActionCreate, TargetIdent (QualifiedIdentifier tSchema tName)) ->
-          case mutateSqlParts tSchema tName of
-            Left errorResponse -> return errorResponse
-            Right (sq, mq) -> do
-              let pkCols = tablePKCols dbStructure tSchema tName
-                  stm = createWriteStatement sq mq
-                    (contentType == CTSingularJSON) True
-                    (contentType == CTTextCSV) (iPreferRepresentation apiRequest) pkCols pgVer prepared
-              row <- H.statement mempty stm
-              let (_, queryTotal, fields, body, gucHeaders, gucStatus) = row
-                  gucs =  (,) <$> gucHeaders <*> gucStatus
-              case gucs of
-                Left err -> return $ errorResponseFor err
-                Right (ghdrs, gstatus) -> do
-                  let
-                    (ctHeaders, rBody) = if iPreferRepresentation apiRequest == Full
-                                          then ([Just $ toHeader contentType, profileH], toS body)
-                                          else ([], mempty)
-                    status = fromMaybe status201 gstatus
-                    headers = addHeadersIfNotIncluded (catMaybes ([
-                          if null fields
-                            then Nothing
-                            else Just $ locationH tName fields
-                        , Just $ contentRangeH 1 0 $ if shouldCount then Just queryTotal else Nothing
-                        , if null pkCols && isNothing (iOnConflict apiRequest)
-                            then Nothing
-                            else (\x -> ("Preference-Applied", BS.pack (show x))) <$> iPreferResolution apiRequest
-                        ] ++ ctHeaders)) (unwrapGucHeader <$> ghdrs)
-                  if contentType == CTSingularJSON && queryTotal /= 1
-                    then do
-                      HT.condemn
-                      return . errorResponseFor . singularityError $ queryTotal
-                    else
-                      return $ responseLBS status headers rBody
-
-        (ActionUpdate, TargetIdent (QualifiedIdentifier tSchema tName)) ->
-          case mutateSqlParts tSchema tName of
-            Left errorResponse -> return errorResponse
-            Right (sq, mq) -> do
-              row <- H.statement mempty $
-                     createWriteStatement sq mq
-                       (contentType == CTSingularJSON) False (contentType == CTTextCSV)
-                       (iPreferRepresentation apiRequest) mempty pgVer prepared
-              let (_, queryTotal, _, body, gucHeaders, gucStatus) = row
-                  gucs =  (,) <$> gucHeaders <*> gucStatus
-              case gucs of
-                Left err -> return $ errorResponseFor err
-                Right (ghdrs, gstatus) -> do
-                  let
-                    updateIsNoOp = S.null (iColumns apiRequest)
-                    defStatus | queryTotal == 0 && not updateIsNoOp      = status404
-                              | iPreferRepresentation apiRequest == Full = status200
-                              | otherwise                                = status204
-                    status = fromMaybe defStatus gstatus
-                    contentRangeHeader = contentRangeH 0 (queryTotal - 1) $ if shouldCount then Just queryTotal else Nothing
-                    (ctHeaders, rBody) = if iPreferRepresentation apiRequest == Full
-                                          then ([Just $ toHeader contentType, profileH], toS body)
-                                          else ([], mempty)
-                    headers = addHeadersIfNotIncluded (catMaybes ctHeaders ++ [contentRangeHeader]) (unwrapGucHeader <$> ghdrs)
-                  if contentType == CTSingularJSON && queryTotal /= 1
-                    then do
-                      HT.condemn
-                      return . errorResponseFor . singularityError $ queryTotal
-                    else
-                      return $ responseLBS status headers rBody
-
-        (ActionSingleUpsert, TargetIdent (QualifiedIdentifier tSchema tName)) ->
-          case mutateSqlParts tSchema tName of
-            Left errorResponse -> return errorResponse
-            Right (sq, mq) ->
-              if topLevelRange /= allRange
-                then return . errorResponseFor $ PutRangeNotAllowedError
-              else do
-                row <- H.statement mempty $
-                       createWriteStatement sq mq (contentType == CTSingularJSON) False
-                                            (contentType == CTTextCSV) (iPreferRepresentation apiRequest) mempty pgVer prepared
-                let (_, queryTotal, _, body, gucHeaders, gucStatus) = row
-                    gucs =  (,) <$> gucHeaders <*> gucStatus
-                case gucs of
-                  Left err -> return $ errorResponseFor err
-                  Right (ghdrs, gstatus) -> do
-                    let headers = addHeadersIfNotIncluded (catMaybes [Just $ toHeader contentType, profileH]) (unwrapGucHeader <$> ghdrs)
-                        (defStatus, rBody) = if iPreferRepresentation apiRequest == Full then (status200, toS body) else (status204, mempty)
-                        status = fromMaybe defStatus gstatus
-                    -- Makes sure the querystring pk matches the payload pk
-                    -- e.g. PUT /items?id=eq.1 { "id" : 1, .. } is accepted, PUT /items?id=eq.14 { "id" : 2, .. } is rejected
-                    -- If this condition is not satisfied then nothing is inserted, check the WHERE for INSERT in QueryBuilder.hs to see how it's done
-                    if queryTotal /= 1
-                      then do
-                        HT.condemn
-                        return . errorResponseFor $ PutMatchingPkError
-                      else
-                        return $ responseLBS status headers rBody
-
-        (ActionDelete, TargetIdent (QualifiedIdentifier tSchema tName)) ->
-          case mutateSqlParts tSchema tName of
-            Left errorResponse -> return errorResponse
-            Right (sq, mq) -> do
-              let stm = createWriteStatement sq mq
-                    (contentType == CTSingularJSON) False
-                    (contentType == CTTextCSV)
-                    (iPreferRepresentation apiRequest) mempty pgVer prepared
-              row <- H.statement mempty stm
-              let (_, queryTotal, _, body, gucHeaders, gucStatus) = row
-                  gucs =  (,) <$> gucHeaders <*> gucStatus
-              case gucs of
-                Left err -> return $ errorResponseFor err
-                Right (ghdrs, gstatus) -> do
-                  let
-                    defStatus = if iPreferRepresentation apiRequest == Full then status200 else status204
-                    status = fromMaybe defStatus gstatus
-                    contentRangeHeader = contentRangeH 1 0 $ if shouldCount then Just queryTotal else Nothing
-                    (ctHeaders, rBody) = if iPreferRepresentation apiRequest == Full
-                                          then ([Just $ toHeader contentType, profileH], toS body)
-                                          else ([], mempty)
-                    headers = addHeadersIfNotIncluded (catMaybes ctHeaders ++ [contentRangeHeader]) (unwrapGucHeader <$> ghdrs)
-                  if contentType == CTSingularJSON
-                     && queryTotal /= 1
-                    then do
-                      HT.condemn
-                      return . errorResponseFor . singularityError $ queryTotal
-                    else
-                      return $ responseLBS status headers rBody
-
-        (ActionInfo, TargetIdent (QualifiedIdentifier tSchema tTable)) ->
-          let mTable = find (\t -> tableName t == tTable && tableSchema t == tSchema) (dbTables dbStructure) in
-          case mTable of
-            Nothing -> return notFound
-            Just table ->
-              let allowH = (hAllow, if tableInsertable table then "GET,POST,PATCH,DELETE" else "GET")
-                  allOrigins = ("Access-Control-Allow-Origin", "*") :: Header in
-              return $ responseLBS status200 [allOrigins, allowH] mempty
-
-        (ActionInvoke invMethod, TargetProc proc@ProcDescription{pdSchema, pdName} _) ->
-          let tName = fromMaybe pdName $ procTableName proc in
-          case readSqlParts pdSchema tName of
-            Left errorResponse -> return errorResponse
-            Right (q, cq, bField, returning) -> do
-              let
-                preferParams = iPreferParameters apiRequest
-                pq = requestToCallProcQuery (QualifiedIdentifier pdSchema pdName) (specifiedProcArgs (iColumns apiRequest) proc)
-                       (iPayload apiRequest) returnsScalar preferParams returning
-                stm = callProcStatement returnsScalar returnsSingle pq q cq shouldCount (contentType == CTSingularJSON)
-                        (contentType == CTTextCSV) (preferParams == Just MultipleObjects) bField pgVer prepared
-              row <- H.statement mempty stm
-              let (tableTotal, queryTotal, body, gucHeaders, gucStatus) = row
-                  gucs =  (,) <$> gucHeaders <*> gucStatus
-              case gucs of
-                Left err -> return $ errorResponseFor err
-                Right (ghdrs, gstatus) -> do
-                  let (rangeStatus, contentRange) = rangeStatusHeader topLevelRange queryTotal tableTotal
-                      status = fromMaybe rangeStatus gstatus
-                      headers = addHeadersIfNotIncluded
-                        (catMaybes [Just $ toHeader contentType, Just contentRange, profileH])
-                        (unwrapGucHeader <$> ghdrs)
-                      rBody = if invMethod == InvHead then mempty else toS body
-                  if contentType == CTSingularJSON && queryTotal /= 1
-                    then do
-                      HT.condemn
-                      return . errorResponseFor . singularityError $ queryTotal
-                    else
-                      return $ responseLBS status headers rBody
-
-        (ActionInspect headersOnly, TargetDefaultSpec tSchema) -> do
-          let host = configServerHost conf
-              port = toInteger $ configServerPort conf
-              proxy = pickProxy $ toS <$> configOpenApiServerProxyUri conf
-              uri Nothing = ("http", host, port, "/")
-              uri (Just Proxy { proxyScheme = s, proxyHost = h, proxyPort = p, proxyPath = b }) = (s, h, p, b)
-              uri' = uri proxy
-              toTableInfo :: [Table] -> [(Table, [Column], [Text])]
-              toTableInfo = map (\t -> let (s, tn) = (tableSchema t, tableName t) in (t, tableCols dbStructure s tn, tablePKCols dbStructure s tn))
-              encodeApi ti sd procs = encodeOpenAPI (concat $ M.elems procs) (toTableInfo ti) uri' sd $ dbPrimaryKeys dbStructure
-
-          body <- encodeApi <$>
-            H.statement tSchema (accessibleTables prepared) <*>
-            H.statement tSchema (schemaDescription prepared) <*>
-            H.statement tSchema (accessibleProcs prepared)
-          return $ responseLBS status200 (catMaybes [Just $ toHeader CTOpenAPI, profileH]) (if headersOnly then mempty else toS body)
-
-        _ -> return notFound
-
-      where
-        notFound = responseLBS status404 mempty ""
-        maxRows = configDbMaxRows conf
-        prepared = configDbPreparedStatements conf
-        exactCount = iPreferCount apiRequest == Just ExactCount
-        estimatedCount = iPreferCount apiRequest == Just EstimatedCount
-        plannedCount = iPreferCount apiRequest == Just PlannedCount
-        shouldCount = exactCount || estimatedCount
-        topLevelRange = iTopLevelRange apiRequest
-        returnsScalar =
-          case iTarget apiRequest of
-            TargetProc proc _ -> procReturnsScalar proc
-            _                 -> False
-        returnsSingle =
-          case iTarget apiRequest of
-            TargetProc proc _ -> procReturnsSingle proc
-            _                 -> False
-        pgVer = pgVersion dbStructure
-        profileH = contentProfileH <$> iProfile apiRequest
-
-        readSqlParts s t =
-          let
-            readReq = readRequest s t maxRows (dbRelations dbStructure) apiRequest
-            returnings :: ReadRequest -> Either Response [FieldName]
-            returnings rr = Right (returningCols rr [])
-          in
-          (,,,) <$>
-          (readRequestToQuery <$> readReq) <*>
-          (readRequestToCountQuery <$> readReq) <*>
-          (binaryField contentType rawContentTypes returnsScalar =<< readReq) <*>
-          (returnings =<< readReq)
-
-        mutateSqlParts s t =
-          let
-            readReq = readRequest s t maxRows (dbRelations dbStructure) apiRequest
-            mutReq = mutateRequest s t apiRequest (tablePKCols dbStructure s t) =<< readReq
-          in
-          (,) <$>
-          (readRequestToQuery <$> readReq) <*>
-          (mutateRequestToQuery <$> mutReq)
-
-responseContentTypeOrError :: [ContentType] -> [ContentType] -> Action -> Target -> Either Response ContentType
-responseContentTypeOrError accepts rawContentTypes action target = serves contentTypesForRequest accepts
-  where
-    contentTypesForRequest = case action of
-      ActionRead _       ->  [CTApplicationJSON, CTSingularJSON, CTTextCSV]
-                             ++ rawContentTypes
-      ActionCreate       ->  [CTApplicationJSON, CTSingularJSON, CTTextCSV]
-      ActionUpdate       ->  [CTApplicationJSON, CTSingularJSON, CTTextCSV]
-      ActionDelete       ->  [CTApplicationJSON, CTSingularJSON, CTTextCSV]
-      ActionInvoke _     ->  [CTApplicationJSON, CTSingularJSON, CTTextCSV]
-                             ++ rawContentTypes
-                             ++ [CTOpenAPI | tpIsRootSpec target]
-      ActionInspect _    ->  [CTOpenAPI, CTApplicationJSON]
-      ActionInfo         ->  [CTTextCSV]
-      ActionSingleUpsert ->  [CTApplicationJSON, CTSingularJSON, CTTextCSV]
-    serves sProduces cAccepts =
-      case mutuallyAgreeable sProduces cAccepts of
-        Nothing -> Left . errorResponseFor . ContentTypeError . map toMime $ cAccepts
-        Just ct -> Right ct
-
-{-
-  | If raw(binary) output is requested, check that ContentType is one of the admitted rawContentTypes and that
-  | `?select=...` contains only one field other than `*`
-}
-binaryField :: ContentType -> [ContentType] -> Bool -> ReadRequest -> Either Response (Maybe FieldName)
-binaryField ct rawContentTypes isScalarProc readReq
-  | isScalarProc =
-      if ct `elem` rawContentTypes
-        then Right $ Just "pgrst_scalar"
-        else Right Nothing
-  | ct `elem` rawContentTypes =
-      let fieldName = headMay fldNames in
-      if length fldNames == 1 && fieldName /= Just "*"
-        then Right fieldName
-        else Left . errorResponseFor $ BinaryFieldError ct
-  | otherwise = Right Nothing
-  where
-    fldNames = fstFieldNames readReq
-
-locationH :: TableName -> [BS.ByteString] -> Header
-locationH tName fields =
  let
-    locationFields = renderSimpleQuery True $ splitKeyValue <$> fields
-  in
-    (hLocation, "/" <> toS tName <> locationFields)
+    handleReq apiReq =
+      handleRequest $ RequestContext conf dbStructure apiReq contentType
+
+  runDbHandler pool (txMode apiRequest) jwtClaims .
+    Middleware.optionalRollback conf apiRequest $
+      Middleware.runPgLocals conf jwtClaims handleReq apiRequest
+
+runDbHandler :: SQL.Pool -> SQL.Mode -> Auth.JWTClaims -> DbHandler a -> Handler IO a
+runDbHandler pool mode jwtClaims handler = do
+  dbResp <-
+    lift . SQL.use pool . SQL.transaction SQL.ReadCommitted mode $ runExceptT handler
+
+  resp <-
+    liftEither . mapLeft Error.PgErr $
+      mapLeft (Error.PgError $ Auth.containsRole jwtClaims) dbResp
+
+  liftEither resp
+
+handleRequest :: RequestContext -> DbHandler Wai.Response
+handleRequest context@(RequestContext _ _ ApiRequest{..} _) =
+  case (iAction, iTarget) of
+    (ActionRead headersOnly, TargetIdent identifier) ->
+      handleRead headersOnly identifier context
+    (ActionCreate, TargetIdent identifier) ->
+      handleCreate identifier context
+    (ActionUpdate, TargetIdent identifier) ->
+      handleUpdate identifier context
+    (ActionSingleUpsert, TargetIdent identifier) ->
+      handleSingleUpsert identifier context
+    (ActionDelete, TargetIdent identifier) ->
+      handleDelete identifier context
+    (ActionInfo, TargetIdent identifier) ->
+      handleInfo identifier context
+    (ActionInvoke invMethod, TargetProc proc _) ->
+      handleInvoke invMethod proc context
+    (ActionInspect headersOnly, TargetDefaultSpec tSchema) ->
+      handleOpenApi headersOnly tSchema context
+    _ ->
+      throwError Error.NotFound
+
+handleRead :: Bool -> QualifiedIdentifier -> RequestContext -> DbHandler Wai.Response
+handleRead headersOnly identifier context@RequestContext{..} = do
+  req <- readRequest identifier context
+  bField <- binaryField context req
+
+  let
+    ApiRequest{..} = ctxApiRequest
+    AppConfig{..} = ctxConfig
+    countQuery = QueryBuilder.readRequestToCountQuery req
+
+  (tableTotal, queryTotal, _ , body, gucHeaders, gucStatus) <-
+    lift . SQL.statement mempty $
+      Statements.createReadStatement
+        (QueryBuilder.readRequestToQuery req)
+        (if iPreferCount == Just EstimatedCount then
+           -- LIMIT maxRows + 1 so we can determine below that maxRows was surpassed
+           QueryBuilder.limitedQuery countQuery ((+ 1) <$> configDbMaxRows)
+         else
+           countQuery
+        )
+        (ctxContentType == CTSingularJSON)
+        (shouldCount iPreferCount)
+        (ctxContentType == CTTextCSV)
+        bField
+        (pgVersion ctxDbStructure)
+        configDbPreparedStatements
+
+  total <- readTotal ctxConfig ctxApiRequest tableTotal countQuery
+  response <- liftEither $ gucResponse <$> gucStatus <*> gucHeaders
+
+  let
+    (status, contentRange) = RangeQuery.rangeStatusHeader iTopLevelRange queryTotal total
+    headers =
+      [ contentRange
+      , ( "Content-Location"
+        , "/"
+            <> toS (qiName identifier)
+            <> if BS8.null iCanonicalQS then mempty else "?" <> toS iCanonicalQS
+        )
+      ]
+      ++ contentTypeHeaders context
+
+  failNotSingular ctxContentType queryTotal . response status headers $
+    if headersOnly then mempty else toS body
+
+readTotal :: AppConfig -> ApiRequest -> Maybe Int64 -> SQL.Snippet -> DbHandler (Maybe Int64)
+readTotal AppConfig{..} ApiRequest{..} tableTotal countQuery =
+  case iPreferCount of
+    Just PlannedCount ->
+      explain
+    Just EstimatedCount ->
+      if tableTotal > (fromIntegral <$> configDbMaxRows) then
+        max tableTotal <$> explain
+      else
+        return tableTotal
+    _ ->
+      return tableTotal
  where
-    splitKeyValue :: BS.ByteString -> (BS.ByteString, BS.ByteString)
-    splitKeyValue kv =
-      let (k, v) = BS.break (== '=') kv
-      in (k, BS.tail v)
+    explain =
+      lift . SQL.statement mempty . Statements.createExplainStatement countQuery $
+        configDbPreparedStatements

-contentLocationH :: TableName -> ByteString -> Header
-contentLocationH tName qString =
-  ("Content-Location", "/" <> toS tName <> if BS.null qString then mempty else "?" <> toS qString)
+handleCreate :: QualifiedIdentifier -> RequestContext -> DbHandler Wai.Response
+handleCreate identifier@QualifiedIdentifier{..} context@RequestContext{..} = do
+  let
+    ApiRequest{..} = ctxApiRequest
+    pkCols = tablePKCols ctxDbStructure qiSchema qiName

-contentProfileH :: Schema -> Header
-contentProfileH schema =
-   ("Content-Profile", toS schema)
+  WriteQueryResult{..} <- writeQuery identifier True pkCols context
+
+  let
+    response = gucResponse resGucStatus resGucHeaders
+    headers =
+      catMaybes
+        [ if null resFields then
+            Nothing
+          else
+            Just
+              ( HTTP.hLocation
+              , "/"
+                  <> toS qiName
+                  <> HTTP.renderSimpleQuery True (splitKeyValue <$> resFields)
+              )
+        , Just . RangeQuery.contentRangeH 1 0 $
+            if shouldCount iPreferCount then Just resQueryTotal else Nothing
+        , if null pkCols && isNothing iOnConflict then
+            Nothing
+          else
+            (\x -> ("Preference-Applied", BS8.pack $ show x)) <$> iPreferResolution
+        ]
+
+  failNotSingular ctxContentType resQueryTotal $
+    if iPreferRepresentation == Full then
+      response HTTP.status201 (headers ++ contentTypeHeaders context) (toS resBody)
+    else
+      response HTTP.status201 headers mempty
+
+handleUpdate :: QualifiedIdentifier -> RequestContext -> DbHandler Wai.Response
+handleUpdate identifier context@(RequestContext _ _ ApiRequest{..} contentType) = do
+  WriteQueryResult{..} <- writeQuery identifier False mempty context
+
+  let
+    response = gucResponse resGucStatus resGucHeaders
+    fullRepr = iPreferRepresentation == Full
+    updateIsNoOp = Set.null iColumns
+    status
+      | resQueryTotal == 0 && not updateIsNoOp = HTTP.status404
+      | fullRepr = HTTP.status200
+      | otherwise = HTTP.status204
+    contentRangeHeader =
+      RangeQuery.contentRangeH 0 (resQueryTotal - 1) $
+        if shouldCount iPreferCount then Just resQueryTotal else Nothing
+
+  failNotSingular contentType resQueryTotal $
+    if fullRepr then
+      response status (contentTypeHeaders context ++ [contentRangeHeader]) (toS resBody)
+    else
+      response status [contentRangeHeader] mempty
+
+handleSingleUpsert :: QualifiedIdentifier -> RequestContext-> DbHandler Wai.Response
+handleSingleUpsert identifier context@(RequestContext _ _ ApiRequest{..} _) = do
+  when (iTopLevelRange /= RangeQuery.allRange) $
+    throwError Error.PutRangeNotAllowedError
+
+  WriteQueryResult{..} <- writeQuery identifier False mempty context
+
+  let response = gucResponse resGucStatus resGucHeaders
+
+  -- Makes sure the querystring pk matches the payload pk
+  -- e.g. PUT /items?id=eq.1 { "id" : 1, .. } is accepted,
+  -- PUT /items?id=eq.14 { "id" : 2, .. } is rejected.
+  -- If this condition is not satisfied then nothing is inserted,
+  -- check the WHERE for INSERT in QueryBuilder.hs to see how it's done
+  when (resQueryTotal /= 1) $ do
+    lift SQL.condemn
+    throwError Error.PutMatchingPkError
+
+  return $
+    if iPreferRepresentation == Full then
+      response HTTP.status200 (contentTypeHeaders context) (toS resBody)
+    else
+      response HTTP.status204 (contentTypeHeaders context) mempty
+
+handleDelete :: QualifiedIdentifier -> RequestContext -> DbHandler Wai.Response
+handleDelete identifier context@(RequestContext _ _ ApiRequest{..} contentType) = do
+  WriteQueryResult{..} <- writeQuery identifier False mempty context
+
+  let
+    response = gucResponse resGucStatus resGucHeaders
+    contentRangeHeader =
+      RangeQuery.contentRangeH 1 0 $
+        if shouldCount iPreferCount then Just resQueryTotal else Nothing
+
+  failNotSingular contentType resQueryTotal $
+    if iPreferRepresentation == Full then
+      response HTTP.status200
+        (contentTypeHeaders context ++ [contentRangeHeader])
+        (toS resBody)
+    else
+      response HTTP.status204 [contentRangeHeader] mempty
+
+handleInfo :: Monad m => QualifiedIdentifier -> RequestContext -> Handler m Wai.Response
+handleInfo identifier RequestContext{..} =
+  case find tableMatches $ dbTables ctxDbStructure of
+    Just table ->
+      return $ Wai.responseLBS HTTP.status200 [allOrigins, allowH table] mempty
+    Nothing ->
+      throwError Error.NotFound
+  where
+    allOrigins = ("Access-Control-Allow-Origin", "*")
+    allowH table =
+      ( HTTP.hAllow
+      , if tableInsertable table then "GET,POST,PATCH,DELETE" else "GET"
+      )
+    tableMatches table =
+      tableName table == qiName identifier
+      && tableSchema table == qiSchema identifier
+
+handleInvoke :: InvokeMethod -> ProcDescription -> RequestContext -> DbHandler Wai.Response
+handleInvoke invMethod proc context@RequestContext{..} = do
+  let
+    ApiRequest{..} = ctxApiRequest
+
+    identifier =
+      QualifiedIdentifier
+        (pdSchema proc)
+        (fromMaybe (pdName proc) $ procTableName proc)
+
+    returnsSingle (ApiRequest.TargetProc target _) = procReturnsSingle target
+    returnsSingle _                                = False
+
+  req <- readRequest identifier context
+  bField <- binaryField context req
+
+  (tableTotal, queryTotal, body, gucHeaders, gucStatus) <-
+    lift . SQL.statement mempty $
+      Statements.callProcStatement
+        (returnsScalar iTarget)
+        (returnsSingle iTarget)
+        (QueryBuilder.requestToCallProcQuery
+          (QualifiedIdentifier (pdSchema proc) (pdName proc))
+          (specifiedProcArgs iColumns proc)
+          iPayload
+          (returnsScalar iTarget)
+          iPreferParameters
+          (ReqBuilder.returningCols req [])
+        )
+        (QueryBuilder.readRequestToQuery req)
+        (QueryBuilder.readRequestToCountQuery req)
+        (shouldCount iPreferCount)
+        (ctxContentType == CTSingularJSON)
+        (ctxContentType == CTTextCSV)
+        (iPreferParameters == Just MultipleObjects)
+        bField
+        (pgVersion ctxDbStructure)
+        (configDbPreparedStatements ctxConfig)
+
+  response <- liftEither $ gucResponse <$> gucStatus <*> gucHeaders
+
+  let
+    (status, contentRange) =
+      RangeQuery.rangeStatusHeader iTopLevelRange queryTotal tableTotal
+
+  failNotSingular ctxContentType queryTotal $
+    response status
+      (contentTypeHeaders context ++ [contentRange])
+      (if invMethod == InvHead then mempty else toS body)
+
+handleOpenApi :: Bool -> Schema -> RequestContext -> DbHandler Wai.Response
+handleOpenApi headersOnly tSchema (RequestContext conf@AppConfig{..} dbStructure apiRequest _) = do
+  body <-
+    lift $
+      OpenAPI.encode conf dbStructure
+        <$> SQL.statement tSchema (DbStructure.accessibleTables configDbPreparedStatements)
+        <*> SQL.statement tSchema (DbStructure.schemaDescription configDbPreparedStatements)
+        <*> SQL.statement tSchema (DbStructure.accessibleProcs configDbPreparedStatements)
+
+  return $
+    Wai.responseLBS HTTP.status200
+      (toHeader CTOpenAPI : maybeToList (profileHeader apiRequest))
+      (if headersOnly then mempty else toS body)
+
+txMode :: ApiRequest -> SQL.Mode
+txMode ApiRequest{..} =
+  case (iAction, iTarget) of
+    (ActionRead _, _) ->
+      SQL.Read
+    (ActionInfo, _) ->
+      SQL.Read
+    (ActionInspect _, _) ->
+      SQL.Read
+    (ActionInvoke InvGet, _) ->
+      SQL.Read
+    (ActionInvoke InvHead, _) ->
+      SQL.Read
+    (ActionInvoke InvPost, TargetProc ProcDescription{pdVolatility=Stable} _) ->
+      SQL.Read
+    (ActionInvoke InvPost, TargetProc ProcDescription{pdVolatility=Immutable} _) ->
+      SQL.Read
+    _ ->
+      SQL.Write
+
+-- | Result from executing a write query on the database
+data WriteQueryResult = WriteQueryResult
+  { resQueryTotal :: Int64
+  , resFields     :: [ByteString]
+  , resBody       :: ByteString
+  , resGucStatus  :: Maybe HTTP.Status
+  , resGucHeaders :: [GucHeader]
+  }
+
+writeQuery :: QualifiedIdentifier -> Bool -> [Text] -> RequestContext -> DbHandler WriteQueryResult
+writeQuery identifier@QualifiedIdentifier{..} isInsert pkCols context@RequestContext{..} = do
+  readReq <- readRequest identifier context
+
+  mutateReq <-
+    liftEither $
+      ReqBuilder.mutateRequest qiSchema qiName ctxApiRequest
+        (tablePKCols ctxDbStructure qiSchema qiName)
+        readReq
+
+  (_, queryTotal, fields, body, gucHeaders, gucStatus) <-
+    lift . SQL.statement mempty $
+      Statements.createWriteStatement
+        (QueryBuilder.readRequestToQuery readReq)
+        (QueryBuilder.mutateRequestToQuery mutateReq)
+        (ctxContentType == CTSingularJSON)
+        isInsert
+        (ctxContentType == CTTextCSV)
+        (iPreferRepresentation ctxApiRequest)
+        pkCols
+        (pgVersion ctxDbStructure)
+        (configDbPreparedStatements ctxConfig)
+
+  liftEither $ WriteQueryResult queryTotal fields body <$> gucStatus <*> gucHeaders
+
+-- | Response with headers and status overridden from GUCs.
+gucResponse
+  :: Maybe HTTP.Status
+  -> [GucHeader]
+  -> HTTP.Status
+  -> [HTTP.Header]
+  -> LBS.ByteString
+  -> Wai.Response
+gucResponse gucStatus gucHeaders status headers =
+  Wai.responseLBS (fromMaybe status gucStatus) $
+    addHeadersIfNotIncluded headers (map unwrapGucHeader gucHeaders)
+
+-- |
+-- Fail a response if a single JSON object was requested and not exactly one
+-- was found.
+failNotSingular :: ContentType -> Int64 -> Wai.Response -> DbHandler Wai.Response
+failNotSingular contentType queryTotal response =
+  if contentType == CTSingularJSON && queryTotal /= 1 then
+    do
+      lift SQL.condemn
+      throwError $ Error.singularityError queryTotal
+  else
+    return response
+
+shouldCount :: Maybe PreferCount -> Bool
+shouldCount preferCount =
+  preferCount == Just ExactCount || preferCount == Just EstimatedCount
+
+returnsScalar :: ApiRequest.Target -> Bool
+returnsScalar (TargetProc proc _) = procReturnsScalar proc
+returnsScalar _                   = False
+
+readRequest :: Monad m => QualifiedIdentifier -> RequestContext -> Handler m ReadRequest
+readRequest QualifiedIdentifier{..} (RequestContext AppConfig{..} dbStructure apiRequest _) =
+  liftEither $
+    ReqBuilder.readRequest qiSchema qiName configDbMaxRows
+      (dbRelations dbStructure)
+      apiRequest
+
+contentTypeHeaders :: RequestContext -> [HTTP.Header]
+contentTypeHeaders RequestContext{..} =
+  toHeader ctxContentType : maybeToList (profileHeader ctxApiRequest)
+
+requestContentTypes :: AppConfig -> ApiRequest -> [ContentType]
+requestContentTypes conf ApiRequest{..} =
+  case iAction of
+    ActionRead _    -> defaultContentTypes ++ rawContentTypes conf
+    ActionInvoke _  -> invokeContentTypes
+    ActionInspect _ -> [CTOpenAPI, CTApplicationJSON]
+    ActionInfo      -> [CTTextCSV]
+    _               -> defaultContentTypes
+  where
+    invokeContentTypes =
+      defaultContentTypes
+        ++ rawContentTypes conf
+        ++ [CTOpenAPI | ApiRequest.tpIsRootSpec iTarget]
+    defaultContentTypes =
+      [CTApplicationJSON, CTSingularJSON, CTTextCSV]
+
+-- |
+-- If raw(binary) output is requested, check that ContentType is one of the admitted
+-- rawContentTypes and that`?select=...` contains only one field other than `*`
+binaryField :: Monad m => RequestContext -> ReadRequest -> Handler m (Maybe FieldName)
+binaryField RequestContext{..} readReq
+  | returnsScalar (iTarget ctxApiRequest) && ctxContentType `elem` rawContentTypes ctxConfig =
+      return $ Just "pgrst_scalar"
+  | ctxContentType `elem` rawContentTypes ctxConfig =
+      let
+        fldNames = fstFieldNames readReq
+        fieldName = headMay fldNames
+      in
+      if length fldNames == 1 && fieldName /= Just "*" then
+        return fieldName
+      else
+        throwError $ Error.BinaryFieldError ctxContentType
+  | otherwise =
+      return Nothing
+
+rawContentTypes :: AppConfig -> [ContentType]
+rawContentTypes AppConfig{..} =
+  (decodeContentType <$> configRawMediaTypes) `union` [CTOctetStream, CTTextPlain]
+
+profileHeader :: ApiRequest -> Maybe HTTP.Header
+profileHeader ApiRequest{..} =
+  (,) "Content-Profile" <$> (toS <$> iProfile)
+
+splitKeyValue :: ByteString -> (ByteString, ByteString)
+splitKeyValue kv =
+  (k, BS8.tail v)
+  where
+    (k, v) = BS8.break (== '=') kv
@@ -1,5 +1,3 @@
-{-# LANGUAGE FlexibleContexts #-}
-{-# LANGUAGE LambdaCase       #-}
 {-|
 Module      : PostgREST.Auth
 Description : PostgREST authorization functions.
@@ -12,108 +10,70 @@ Authentication should always be implemented in an external service.
 In the test suite there is an example of simple login function that can be used for a
 very simple authentication system inside the PostgreSQL database.
 -}
-module PostgREST.Auth (
-    containsRole
-  , jwtClaims
-  , attemptJwtClaims
-  , parseSecret
-  ) where
+{-# LANGUAGE RecordWildCards #-}
+module PostgREST.Auth (containsRole, jwtClaims, JWTClaims) where

-import qualified Crypto.JOSE.Types   as JOSE.Types
+import qualified Crypto.JWT          as JWT
 import qualified Data.Aeson          as JSON
 import qualified Data.HashMap.Strict as M
-import           Data.Vector         as V
+import qualified Data.Vector         as V

-import Control.Lens    (set)
-import Data.Time.Clock (UTCTime)
+import Control.Lens            (set)
+import Control.Monad.Except    (liftEither)
+import Data.Either.Combinators (mapLeft)
+import Data.Time.Clock         (UTCTime)

-import Crypto.JWT
+import PostgREST.Config (AppConfig (..))
+import PostgREST.Error  (Error (..))
+import PostgREST.Types  (JSPath, JSPathExp (..))

-import PostgREST.Error (SimpleError (..))
-import PostgREST.Types
-import Protolude       hiding (toS)
-import Protolude.Conv  (toS)
-
-{-|
-  Possible situations encountered with client JWTs
-}
-data JWTAttempt = JWTInvalid JWTError
-                | JWTMissingSecret
-                | JWTClaims (M.HashMap Text JSON.Value)
+import Protolude


-jwtClaims :: JWTAttempt -> Either SimpleError (M.HashMap Text JSON.Value)
-jwtClaims attempt =
-  case attempt of
-    JWTMissingSecret      -> Left JwtTokenMissing
-    JWTInvalid JWTExpired -> Left $ JwtTokenInvalid "JWT expired"
-    JWTInvalid e          -> Left $ JwtTokenInvalid $ show e
-    JWTClaims claims      -> Right claims
+type JWTClaims = M.HashMap Text JSON.Value

-{-|
-  Receives the JWT secret and audience (from config) and a JWT and returns a map
-  of JWT claims.
-}
-attemptJwtClaims :: Maybe JWKSet -> Maybe StringOrURI -> LByteString -> UTCTime -> JSPath -> IO JWTAttempt
-attemptJwtClaims _ _ "" _ _ = return $ JWTClaims M.empty
-attemptJwtClaims maybeSecret audience payload time jspath =
-  case maybeSecret of
-    Nothing -> return JWTMissingSecret
-    Just secret -> do
-      let validation = set allowedSkew 1 $ defaultJWTValidationSettings (maybe (const True) (==) audience)
-      eJwt <- runExceptT $ do
-        jwt <- decodeCompact payload
-        verifyClaimsAt validation secret time jwt
-      return $ case eJwt of
-        Left e    -> JWTInvalid e
-        Right jwt -> JWTClaims $ claims2map jwt jspath
+-- | Receives the JWT secret and audience (from config) and a JWT and returns a
+-- map of JWT claims.
+jwtClaims :: Monad m =>
+  AppConfig -> LByteString -> UTCTime -> ExceptT Error m JWTClaims
+jwtClaims _ "" _ = return M.empty
+jwtClaims AppConfig{..} payload time = do
+  secret <- liftEither . maybeToRight JwtTokenMissing $ configJWKS
+  eitherClaims <-
+    lift . runExceptT $
+      JWT.verifyClaimsAt validation secret time =<< JWT.decodeCompact payload
+  liftEither . mapLeft jwtClaimsError $ claimsMap configJwtRoleClaimKey <$> eitherClaims
+  where
+    validation =
+      JWT.defaultJWTValidationSettings audienceCheck & set JWT.allowedSkew 1

-{-|
-  Turn JWT ClaimSet into something easier to work with,
-  also here the jspath is applied to put the "role" in the map
-}
-claims2map :: ClaimsSet -> JSPath -> M.HashMap Text JSON.Value
-claims2map claims jspath = (\case
+    audienceCheck :: JWT.StringOrURI -> Bool
+    audienceCheck = maybe (const True) (==) configJwtAudience
+
+    jwtClaimsError :: JWT.JWTError -> Error
+    jwtClaimsError JWT.JWTExpired = JwtTokenInvalid "JWT expired"
+    jwtClaimsError e              = JwtTokenInvalid $ show e
+
+-- | Turn JWT ClaimSet into something easier to work with.
+--
+-- Also, here the jspath is applied to put the "role" in the map.
+claimsMap :: JSPath -> JWT.ClaimsSet -> JWTClaims
+claimsMap jspath claims =
+  case JSON.toJSON claims of
    val@(JSON.Object o) ->
-      let role = maybe M.empty (M.singleton "role") $
-                 walkJSPath (Just val) jspath in
-      M.delete "role" o `M.union` role -- mutating the map
-    _ -> M.empty
-  ) $ JSON.toJSON claims
+      M.delete "role" o `M.union` role val
+    _ ->
+      M.empty
+  where
+    role value =
+      maybe M.empty (M.singleton "role") $ walkJSPath (Just value) jspath

-walkJSPath :: Maybe JSON.Value -> JSPath -> Maybe JSON.Value
-walkJSPath x                      []                = x
-walkJSPath (Just (JSON.Object o)) (JSPKey key:rest) = walkJSPath (M.lookup key o) rest
-walkJSPath (Just (JSON.Array ar)) (JSPIdx idx:rest) = walkJSPath (ar V.!? idx) rest
-walkJSPath _                      _                 = Nothing
+    walkJSPath :: Maybe JSON.Value -> JSPath -> Maybe JSON.Value
+    walkJSPath x                      []                = x
+    walkJSPath (Just (JSON.Object o)) (JSPKey key:rest) = walkJSPath (M.lookup key o) rest
+    walkJSPath (Just (JSON.Array ar)) (JSPIdx idx:rest) = walkJSPath (ar V.!? idx) rest
+    walkJSPath _                      _                 = Nothing

-{-|
-  Whether a response from jwtClaims contains a role claim
-}
-containsRole :: M.HashMap Text JSON.Value -> Bool
+-- | Whether a response from jwtClaims contains a role claim
+containsRole :: JWTClaims -> Bool
 containsRole = M.member "role"
-
-{-|
-  Parse `jwt-secret` configuration option and turn into a JWKSet.
-
-  There are three ways to specify `jwt-secret`: text secret, JSON Web Key
-  (JWK), or JSON Web Key Set (JWKS). The first two are converted into a JWKSet
-  with one key and the last is converted as is.
-}
-parseSecret :: ByteString -> JWKSet
-parseSecret str =
-  fromMaybe (maybe secret (\jwk' -> JWKSet [jwk']) maybeJWK)
-    maybeJWKSet
- where
-  maybeJWKSet = JSON.decode (toS str) :: Maybe JWKSet
-  maybeJWK = JSON.decode (toS str) :: Maybe JWK
-  secret = JWKSet [jwkFromSecret str]
-
-{-|
-  Internal helper to generate a symmetric HMAC-SHA256 JWK from a text secret.
-}
-jwkFromSecret :: ByteString -> JWK
-jwkFromSecret key =
-  fromKeyMaterial km
- where
-  km = OctKeyMaterial (OctKeyParameters (JOSE.Types.Base64Octets key))
@@ -20,20 +20,24 @@ Other hardcoded options such as the minimum version number also belong here.
 {-# LANGUAGE TemplateHaskell       #-}
 {-# OPTIONS_GHC -fno-warn-type-defaults #-}

-module PostgREST.Config ( prettyVersion
-                        , docsVersion
-                        , CLI (..)
-                        , Command (..)
-                        , AppConfig (..)
-                        , configDbPoolTimeout'
-                        , dumpAppConfig
-                        , Environment
-                        , readCLIShowHelp
-                        , readEnvironment
-                        , readConfig
-                        )
-       where
+module PostgREST.Config
+  ( prettyVersion
+  , docsVersion
+  , CLI (..)
+  , Command (..)
+  , AppConfig (..)
+  , configDbPoolTimeout'
+  , dumpAppConfig
+  , Environment
+  , readCLIShowHelp
+  , readEnvironment
+  , readConfig
+  , parseSecret
+  ) where

+import qualified Crypto.JOSE.Types      as JOSE
+import qualified Crypto.JWT             as JWT
+import qualified Data.Aeson             as JSON
 import qualified Data.ByteString        as B
 import qualified Data.ByteString.Base64 as B64
 import qualified Data.ByteString.Char8  as BS
@@ -42,7 +46,7 @@ import qualified Data.Map.Strict        as M

 import Control.Lens            (preview)
 import Control.Monad           (fail)
-import Crypto.JWT              (JWKSet, StringOrURI, stringOrUri)
+import Crypto.JWT              (JWK, JWKSet, StringOrURI, stringOrUri)
 import Data.Aeson              (encode, toJSON)
 import Data.Either.Combinators (mapLeft)
 import Data.List               (lookup)
@@ -63,9 +67,8 @@ import System.Posix.Types      (FileMode)
 import Control.Applicative
 import Data.Monoid
 import Options.Applicative hiding (str)
-import Text.Heredoc
+import Text.Heredoc        (str)

-import PostgREST.Auth             (parseSecret)
 import PostgREST.Parsers          (pRoleClaimKey)
 import PostgREST.Private.ProxyUri (isMalformedProxyUri)
 import PostgREST.Types            (JSPath, JSPathExp (..),
@@ -593,3 +596,21 @@ loadDbUriFile conf = extractDbUri mDbUri
        Nothing       -> return dbUri
        Just filename -> strip <$> readFile (toS filename)
    setDbUri dbUri = conf {configDbUri = dbUri}
+
+
+{-|
+  Parse `jwt-secret` configuration option and turn into a JWKSet.
+
+  There are three ways to specify `jwt-secret`: text secret, JSON Web Key
+  (JWK), or JSON Web Key Set (JWKS). The first two are converted into a JWKSet
+  with one key and the last is converted as is.
+-}
+parseSecret :: ByteString -> JWKSet
+parseSecret bytes =
+  fromMaybe (maybe secret (\jwk' -> JWT.JWKSet [jwk']) maybeJWK)
+    maybeJWKSet
+ where
+  maybeJWKSet = JSON.decode (toS bytes) :: Maybe JWKSet
+  maybeJWK = JSON.decode (toS bytes) :: Maybe JWK
+  secret = JWT.JWKSet [JWT.fromKeyMaterial keyMaterial]
+  keyMaterial = JWT.OctKeyMaterial . JWT.OctKeyParameters $ JOSE.Base64Octets bytes
@@ -7,7 +7,6 @@ This module is in charge of building an intermediate representation(ReadRequest,
 A query tree is built in case of resource embedding. By inferring the relationship between tables, join conditions are added for every embedded resource.
 -}
 {-# LANGUAGE DuplicateRecordFields #-}
-{-# LANGUAGE FlexibleContexts      #-}
 {-# LANGUAGE LambdaCase            #-}
 {-# LANGUAGE NamedFieldPuns        #-}
 {-# LANGUAGE RecordWildCards       #-}
@@ -28,10 +27,9 @@ import Data.Text               (isInfixOf)

 import Control.Applicative
 import Data.Tree
-import Network.Wai

 import PostgREST.ApiRequest (Action (..), ApiRequest (..))
-import PostgREST.Error      (ApiRequestError (..), errorResponseFor)
+import PostgREST.Error      (ApiRequestError (..), Error (..))
 import PostgREST.Parsers
 import PostgREST.RangeQuery (NonnegRange, allRange, restrictRange)
 import PostgREST.Types
@@ -40,9 +38,9 @@ import Protolude            hiding (from)
 -- | Builds the ReadRequest tree on a number of stages.
 -- | Adds filters, order, limits on its respective nodes.
 -- | Adds joins conditions obtained from resource embedding.
-readRequest :: Schema -> TableName -> Maybe Integer -> [Relation] -> ApiRequest -> Either Response ReadRequest
+readRequest :: Schema -> TableName -> Maybe Integer -> [Relation] -> ApiRequest -> Either Error ReadRequest
 readRequest schema rootTableName maxRows allRels apiRequest  =
-  mapLeft errorResponseFor $
+  mapLeft ApiRequestError $
  treeRestrictRange maxRows =<<
  augmentRequestWithJoin schema rootRels =<<
  addFiltersOrdersRanges apiRequest =<<
@@ -281,8 +279,8 @@ addProperty f (targetNodeName:remainingPath, a) (Node rn forest) =
  where
    pathNode = find (\(Node (_,(nodeName,_,alias,_,_)) _) -> nodeName == targetNodeName || alias == Just targetNodeName) forest

-mutateRequest :: Schema -> TableName -> ApiRequest -> [FieldName] -> ReadRequest -> Either Response MutateRequest
-mutateRequest schema tName apiRequest pkCols readReq = mapLeft errorResponseFor $
+mutateRequest :: Schema -> TableName -> ApiRequest -> [FieldName] -> ReadRequest -> Either Error MutateRequest
+mutateRequest schema tName apiRequest pkCols readReq = mapLeft ApiRequestError $
  case action of
    ActionCreate -> do
        confCols <- case iOnConflict apiRequest of
@@ -3,14 +3,13 @@ Module      : PostgREST.Error
 Description : PostgREST error HTTP responses
 -}
 {-# OPTIONS_GHC -fno-warn-orphans #-}
-{-# LANGUAGE FlexibleInstances #-}
-{-# LANGUAGE RecordWildCards   #-}
+{-# LANGUAGE RecordWildCards #-}

 module PostgREST.Error (
  errorResponseFor
 , ApiRequestError(..)
 , PgError(..)
-, SimpleError(..)
+, Error(..)
 , errorPayload
 , checkIsFatal
 , singularityError
@@ -220,7 +219,7 @@ checkIsFatal (PgError _ (P.SessionError (H.QueryError _ _ (H.ResultError (H.Serv
 checkIsFatal _ = Nothing


-data SimpleError
+data Error
  = GucHeadersError
  | GucStatusError
  | BinaryFieldError ContentType
@@ -231,8 +230,11 @@ data SimpleError
  | JwtTokenInvalid Text
  | SingularityError Integer
  | ContentTypeError [ByteString]
+  | NotFound
+  | ApiRequestError ApiRequestError
+  | PgErr PgError

-instance PgrstError SimpleError where
+instance PgrstError Error where
  status GucHeadersError         = HT.status500
  status GucStatusError          = HT.status500
  status (BinaryFieldError _)    = HT.status406
@@ -243,12 +245,17 @@ instance PgrstError SimpleError where
  status (JwtTokenInvalid _)     = HT.unauthorized401
  status (SingularityError _)    = HT.status406
  status (ContentTypeError _)    = HT.status415
+  status NotFound                = HT.status404
+  status (PgErr err)             = status err
+  status (ApiRequestError err)   = status err

  headers (SingularityError _)     = [toHeader CTSingularJSON]
  headers (JwtTokenInvalid m)      = [toHeader CTApplicationJSON, invalidTokenHeader m]
+  headers (PgErr err)              = headers err
+  headers (ApiRequestError err)    = headers err
  headers _                        = [toHeader CTApplicationJSON]

-instance JSON.ToJSON SimpleError where
+instance JSON.ToJSON Error where
  toJSON GucHeadersError           = JSON.object [
    "message" .= ("response.headers guc must be a JSON array composed of objects with a single key and a string value" :: Text)]
  toJSON GucStatusError           = JSON.object [
@@ -273,10 +280,13 @@ instance JSON.ToJSON SimpleError where
    "message" .= ("Server lacks JWT secret" :: Text)]
  toJSON (JwtTokenInvalid message) = JSON.object [
    "message" .= (message :: Text)]
+  toJSON NotFound = JSON.object []
+  toJSON (PgErr err) = JSON.toJSON err
+  toJSON (ApiRequestError err) = JSON.toJSON err

 invalidTokenHeader :: Text -> Header
 invalidTokenHeader m =
  ("WWW-Authenticate", "Bearer error=\"invalid_token\", " <> "error_description=" <> encodeUtf8 (show m))

-singularityError :: (Integral a) => a -> SimpleError
+singularityError :: (Integral a) => a -> Error
 singularityError = SingularityError . toInteger
@@ -2,11 +2,15 @@
 Module      : PostgREST.Middleware
 Description : Sets CORS policy. Also the PostgreSQL GUCs, role, search_path and pre-request function.
 -}
-{-# OPTIONS_GHC -fno-warn-orphans #-}
-{-# LANGUAGE FlexibleContexts    #-}
-{-# LANGUAGE ScopedTypeVariables #-}
-
-module PostgREST.Middleware where
+{-# LANGUAGE RecordWildCards #-}
+module PostgREST.Middleware
+  ( runPgLocals
+  , pgrstFormat
+  , pgrstMiddleware
+  , defaultCorsPolicy
+  , corsPolicy
+  , optionalRollback
+  ) where

 import qualified Hasql.Decoders                    as HD
 import qualified Hasql.DynamicStatements.Statement as H
@@ -23,8 +27,10 @@ import           Data.Scientific           (FPFormat (..),
                                            isInteger)
 import qualified Data.Text                 as T
 import qualified Hasql.Transaction         as H
+import qualified Network.HTTP.Types.Header as HTTP
 import           Network.HTTP.Types.Status (Status, status400,
                                            status500, statusCode)
+import qualified Network.Wai               as Wai
 import           Network.Wai.Logger        (showSockAddr)
 import           System.Log.FastLogger     (toLogStr)

@@ -35,8 +41,11 @@ import Network.Wai.Middleware.Gzip          (def, gzip)
 import Network.Wai.Middleware.RequestLogger
 import Network.Wai.Middleware.Static        (only, staticPolicy)

+import qualified PostgREST.Types as Types
+
 import PostgREST.ApiRequest   (ApiRequest (..))
 import PostgREST.Config       (AppConfig (..))
+import PostgREST.Error        (Error, errorResponseFor)
 import PostgREST.QueryBuilder (setConfigLocal)
 import PostgREST.Types        (LogLevel (..))
 import Protolude              hiding (head, toS)
@@ -45,13 +54,13 @@ import System.IO.Unsafe       (unsafePerformIO)

 -- | Runs local(transaction scoped) GUCs for every request, plus the pre-request function
 runPgLocals :: AppConfig   -> M.HashMap Text JSON.Value ->
-               (ApiRequest -> H.Transaction Response) ->
-               ApiRequest  -> H.Transaction Response
+               (ApiRequest -> ExceptT Error H.Transaction Response) ->
+               ApiRequest  -> ExceptT Error H.Transaction Response
 runPgLocals conf claims app req = do
-  H.statement mempty $ H.dynamicallyParameterized
+  lift $ H.statement mempty $ H.dynamicallyParameterized
    ("select " <> intercalateSnippet ", " (searchPathSql : roleSql ++ claimsSql ++ [methodSql, pathSql] ++ headersSql ++ cookiesSql ++ appSettingsSql))
    HD.noResult (configDbPreparedStatements conf)
-  traverse_ H.sql preReqSql
+  lift $ traverse_ H.sql preReqSql
  app req
  where
    methodSql = setConfigLocal mempty ("request.method", toS $ iMethod req)
@@ -140,3 +149,30 @@ unquoted (JSON.Number n) =
  toS $ formatScientific Fixed (if isInteger n then Just 0 else Nothing) n
 unquoted (JSON.Bool b) = show b
 unquoted v = toS $ JSON.encode v
+
+-- | Set a transaction to eventually roll back if requested and set respective
+-- headers on the response.
+optionalRollback
+  :: AppConfig
+  -> ApiRequest
+  -> ExceptT Error H.Transaction Wai.Response
+  -> ExceptT Error H.Transaction Wai.Response
+optionalRollback AppConfig{..} ApiRequest{..} transaction = do
+  resp <- catchError transaction $ return . errorResponseFor
+  when (shouldRollback || (configDbTxRollbackAll && not shouldCommit))
+    (lift H.condemn)
+  return $ Wai.mapResponseHeaders preferenceApplied resp
+  where
+    shouldCommit =
+      configDbTxAllowOverride && iPreferTransaction == Just Types.Commit
+    shouldRollback =
+      configDbTxAllowOverride && iPreferTransaction == Just Types.Rollback
+    preferenceApplied
+      | shouldCommit =
+          Types.addHeadersIfNotIncluded
+            [(HTTP.hPreferenceApplied, BS.pack (show Types.Commit))]
+      | shouldRollback =
+          Types.addHeadersIfNotIncluded
+            [(HTTP.hPreferenceApplied, BS.pack (show Types.Rollback))]
+      | otherwise =
+          identity
@@ -2,17 +2,15 @@
 Module      : PostgREST.OpenAPI
 Description : Generates the OpenAPI output
 -}
-{-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE RecordWildCards #-}
+module PostgREST.OpenAPI (encode) where

-module PostgREST.OpenAPI (
-  encodeOpenAPI
-, pickProxy
-) where
-
-import qualified Data.HashSet.InsOrd as Set
+import qualified Data.Aeson           as JSON
+import qualified Data.ByteString.Lazy as LBS
+import qualified Data.HashMap.Strict  as HashMap
+import qualified Data.HashSet.InsOrd  as Set

 import Control.Arrow              ((&&&))
-import Data.Aeson                 (decode, encode)
 import Data.HashMap.Strict.InsOrd (InsOrdHashMap, fromList)
 import Data.Maybe                 (fromJust)
 import Data.String                (IsString (..))
@@ -25,16 +23,29 @@ import Control.Lens
 import Data.Swagger

 import PostgREST.ApiRequest       (ContentType (..))
-import PostgREST.Config           (docsVersion, prettyVersion)
+import PostgREST.Config           (AppConfig (..), docsVersion,
+                                   prettyVersion)
 import PostgREST.Private.ProxyUri (isMalformedProxyUri, toURI)
-import PostgREST.Types            (Column (..), ForeignKey (..),
-                                   PgArg (..), PrimaryKey (..),
+import PostgREST.Types            (Column (..), DbStructure (..),
+                                   ForeignKey (..), PgArg (..),
+                                   PrimaryKey (..),
                                   ProcDescription (..), Proxy (..),
-                                   Table (..), toMime)
+                                   Table (..), tableCols, tableName,
+                                   tablePKCols, tableSchema, toMime)
 import Protolude                  hiding (Proxy, dropWhile, get,
                                   intercalate, toLower, toS, (&))
 import Protolude.Conv             (toS)

+encode :: AppConfig -> DbStructure -> [Table] -> Maybe Text -> HashMap.HashMap k [ProcDescription] -> LBS.ByteString
+encode conf dbStructure tables schemaDescription procs =
+  JSON.encode $
+    postgrestSpec
+      (concat $ HashMap.elems procs)
+      (openApiTableInfo dbStructure <$> tables)
+      (proxyUri conf)
+      schemaDescription
+      (dbPrimaryKeys dbStructure)
+
 makeMimeList :: [ContentType] -> MimeList
 makeMimeList cs = MimeList $ map (fromString . toS . toMime) cs

@@ -63,7 +74,7 @@ makeTableDef pks (t, cs, _) =
 makeProperty :: [PrimaryKey] -> Column -> (Text, Referenced Schema)
 makeProperty pks c = (colName c, Inline s)
  where
-    e = if null $ colEnum c then Nothing else decode $ encode $ colEnum c
+    e = if null $ colEnum c then Nothing else JSON.decode $ JSON.encode $ colEnum c
    fk ForeignKey{fkCol=Column{colTable=Table{tableName=a}, colName=b}} =
      intercalate "" ["This is a Foreign Key to `", a, ".", b, "`.<fk table='", a, "' column='", b, "'/>"]
    pk :: Bool
@@ -80,7 +91,7 @@ makeProperty pks c = (colName c, Inline s)
        colDescription c
    s =
      (mempty :: Schema)
-        & default_ .~ (decode . toS =<< colDefault c)
+        & default_ .~ (JSON.decode . toS =<< colDefault c)
        & description .~ d
        & enum_ .~ e
        & format ?~ colType c
@@ -111,7 +122,7 @@ makePreferParam ts =
  & schema .~ ParamOther ((mempty :: ParamOtherSchema)
    & in_ .~ ParamHeader
    & type_ ?~ SwaggerString
-    & enum_ .~ decode (encode ts))
+    & enum_ .~ JSON.decode (JSON.encode ts))

 makeProcParam :: ProcDescription -> [Referenced Param]
 makeProcParam pd =
@@ -162,7 +173,7 @@ makeParamDefs ti =
      & schema .~ ParamOther ((mempty :: ParamOtherSchema)
        & in_ .~ ParamHeader
        & type_ ?~ SwaggerString
-        & default_ .~ decode "\"items\""))
+        & default_ .~ JSON.decode "\"items\""))
  , ("offset", (mempty :: Param)
      & name        .~ "offset"
      & description ?~ "Limiting and Pagination"
@@ -303,9 +314,6 @@ postgrestSpec pds ti (s, h, p, b) sd pks = (mempty :: Swagger)
      h' = Just $ Host (unpack $ escapeHostName h) (Just (fromInteger p))
      d = fromMaybe "This is a dynamic API generated by PostgREST" sd

-encodeOpenAPI :: [ProcDescription] -> [(Table, [Column], [Text])] -> (Text, Text, Integer, Text) -> Maybe Text -> [PrimaryKey] ->  LByteString
-encodeOpenAPI pds ti uri sd pks = encode $ postgrestSpec pds ti uri sd pks
-
 pickProxy :: Maybe Text -> Maybe Proxy
 pickProxy proxy
  | isNothing proxy = Nothing
@@ -334,3 +342,18 @@ pickProxy proxy
             ("", "http")  -> 80
             ("", "https") -> 443
             _             -> readPort $ unpack $ tail $ pack port'
+
+proxyUri :: AppConfig -> (Text, Text, Integer, Text)
+proxyUri AppConfig{..} =
+  case pickProxy $ toS <$> configOpenApiServerProxyUri of
+    Just Proxy{..} ->
+      (proxyScheme, proxyHost, proxyPort, proxyPath)
+    Nothing ->
+      ("http", configServerHost, toInteger configServerPort, "/")
+
+openApiTableInfo :: DbStructure -> Table -> (Table, [Column], [Text])
+openApiTableInfo dbStructure table =
+  ( table
+  , tableCols dbStructure (tableSchema table) (tableName table)
+  , tablePKCols dbStructure (tableSchema table) (tableName table)
+  )
@@ -45,7 +45,7 @@ import Text.InterpolatedString.Perl6 (q)
    is represented as a list of strings containing variable bindings like
    @"k1=eq.42"@, or the empty list if there is no location header.
 -}
-type ResultsWithCount = (Maybe Int64, Int64, [BS.ByteString], BS.ByteString, Either SimpleError [GucHeader], Either SimpleError (Maybe Status))
+type ResultsWithCount = (Maybe Int64, Int64, [BS.ByteString], BS.ByteString, Either Error [GucHeader], Either Error (Maybe Status))

 createWriteStatement :: H.Snippet -> H.Snippet -> Bool -> Bool -> Bool ->
                        PreferRepresentation -> [Text] -> PgVersion -> Bool ->
@@ -130,7 +130,7 @@ standardRow = (,,,,,) <$> nullableColumn HD.int8 <*> column HD.int8
                      <*> (fromMaybe (Right []) <$> nullableColumn decodeGucHeaders)
                      <*> (fromMaybe (Right Nothing) <$> nullableColumn decodeGucStatus)

-type ProcResults = (Maybe Int64, Int64, ByteString, Either SimpleError [GucHeader], Either SimpleError (Maybe Status))
+type ProcResults = (Maybe Int64, Int64, ByteString, Either Error [GucHeader], Either Error (Maybe Status))

 callProcStatement :: Bool -> Bool -> H.Snippet -> H.Snippet -> H.Snippet -> Bool ->
                     Bool -> Bool -> Bool -> Maybe FieldName -> PgVersion -> Bool ->
@@ -189,10 +189,10 @@ createExplainStatement countQuery =
      let row = HD.singleRow $ column HD.bytea in
      (^? L.nth 0 . L.key "Plan" .  L.key "Plan Rows" . L._Integral) <$> row

-decodeGucHeaders :: HD.Value (Either SimpleError [GucHeader])
+decodeGucHeaders :: HD.Value (Either Error [GucHeader])
 decodeGucHeaders = first (const GucHeadersError) . JSON.eitherDecode . toS <$> HD.bytea

-decodeGucStatus :: HD.Value (Either SimpleError (Maybe Status))
+decodeGucStatus :: HD.Value (Either Error (Maybe Status))
 decodeGucStatus = first (const GucStatusError) . fmap (Just . toEnum . fst) . decimal <$> HD.text

 -- | Get db settings from the connection role. Only used for configuration.
@@ -22,8 +22,7 @@ import Test.Hspec
 import Test.Hspec.Wai
 import Text.Heredoc

-import PostgREST.Auth   (parseSecret)
-import PostgREST.Config (AppConfig (..))
+import PostgREST.Config (AppConfig (..), parseSecret)
 import PostgREST.Types  (JSPathExp (..), LogLevel (..))
 import Protolude        hiding (toS)
 import Protolude.Conv   (toS)
@@ -297,6 +297,7 @@ def test_expected_config_from_db_settings(defaultenv, role, expectedconfig):

    assert dumpconfig(configpath=config, env=env) == expected

+
@pytest.mark.parametrize(
    "config",
    [conf for conf in CONFIGSDIR.iterdir() if conf.suffix == ".config"],
@@ -604,6 +605,7 @@ def test_max_rows_notify_reload(defaultenv):
        # reset max-rows config on the db
        postgrest.session.post("/rpc/reset_max_rows_config")

+
 def test_invalid_role_claim_key_notify_reload(defaultenv):
    "NOTIFY reload config should show an error if role-claim-key is invalid"