Merge branch 'master' into less-invasive-param-lookup-#251

Web/Scotty.hs

@@ -30,13 +30,15 @@ module Web.Scotty
       -- | Note: only one of these should be present in any given route
       -- definition, as they completely replace the current 'Response' body.
     , text, html, file, json, stream, raw
+      -- ** Accessing the fields of the Response
+    , getResponseHeaders, getResponseStatus, getResponseContent
       -- ** Exceptions
     , raise, raiseStatus, throw, rescue, next, finish, defaultHandler, liftAndCatchIO
     , StatusError(..)
       -- * Parsing Parameters
     , Param, Trans.Parsable(..), Trans.readEither
       -- * Types
-    , ScottyM, ActionM, RoutePattern, File, Kilobytes, Handler(..)
+    , ScottyM, ActionM, RoutePattern, File, Content(..), Kilobytes, Handler(..)
     , ScottyState, defaultScottyState
     ) where
 
@@ -48,12 +50,12 @@ import qualified Data.ByteString as BS
 import Data.ByteString.Lazy.Char8 (ByteString)
 import Data.Text.Lazy (Text)
 
-import Network.HTTP.Types (Status, StdMethod)
+import Network.HTTP.Types (Status, StdMethod, ResponseHeaders)
 import Network.Socket (Socket)
 import Network.Wai (Application, Middleware, Request, StreamingBody)
 import Network.Wai.Handler.Warp (Port)
 
-import Web.Scotty.Internal.Types (ScottyT, ActionT, ErrorHandler, Param, RoutePattern, Options, defaultOptions, File, Kilobytes, ScottyState, defaultScottyState, StatusError(..))
+import Web.Scotty.Internal.Types (ScottyT, ActionT, ErrorHandler, Param, RoutePattern, Options, defaultOptions, File, Kilobytes, ScottyState, defaultScottyState, StatusError(..), Content(..))
 import Web.Scotty.Exceptions (Handler(..))
 
 type ScottyM = ScottyT IO
@@ -341,6 +343,18 @@ stream = Trans.stream
 raw :: ByteString -> ActionM ()
 raw = Trans.raw
 
+
+-- | Access the HTTP 'Status' of the Response
+getResponseStatus :: ActionM Status
+getResponseStatus = Trans.getResponseStatus
+-- | Access the HTTP headers of the Response
+getResponseHeaders :: ActionM ResponseHeaders
+getResponseHeaders = Trans.getResponseHeaders
+-- | Access the content of the Response
+getResponseContent :: ActionM Content
+getResponseContent = Trans.getResponseContent
+
+
 -- | get = 'addroute' 'GET'
 get :: RoutePattern -> ActionM () -> ScottyM ()
 get = Trans.get
@@ -439,3 +453,7 @@ function = Trans.function
 -- | Build a route that requires the requested path match exactly, without captures.
 literal :: String -> RoutePattern
 literal = Trans.literal
+
+
+
+

Web/Scotty/Action.hs

@@ -44,6 +44,9 @@ module Web.Scotty.Action
     , status
     , stream
     , text
+    , getResponseStatus
+    , getResponseHeaders
+    , getResponseContent
     , Param
     , Parsable(..)
       -- private to Scotty
@@ -400,6 +403,20 @@ paramsWith f = ActionT (f <$> ask)
 getParams :: ActionEnv -> [Param]
 getParams e = envCaptureParams e <> envFormParams e <> envQueryParams e
 
+
+-- === access the fields of the Response being constructed
+
+-- | Access the HTTP 'Status' of the Response
+getResponseStatus :: (MonadIO m) => ActionT m Status
+getResponseStatus = srStatus <$> getResponseAction
+-- | Access the HTTP headers of the Response
+getResponseHeaders :: (MonadIO m) => ActionT m ResponseHeaders
+getResponseHeaders = srHeaders <$> getResponseAction
+-- | Access the content of the Response
+getResponseContent :: (MonadIO m) => ActionT m Content
+getResponseContent = srContent <$> getResponseAction
+
+
 -- | Minimum implemention: 'parseParam'
 class Parsable a where
     -- | Take a 'T.Text' value and parse it as 'a', or fail with a message.

Web/Scotty/Internal/Types.hs

@@ -1,7 +1,6 @@
 {-# LANGUAGE CPP #-}
 {-# LANGUAGE DeriveDataTypeable #-}
 {-# LANGUAGE DerivingStrategies #-}
-{-# language DerivingVia #-}
 {-# LANGUAGE FlexibleInstances #-}
 {-# LANGUAGE GeneralizedNewtypeDeriving #-}
 {-# LANGUAGE MultiParamTypeClasses #-}
@@ -20,6 +19,7 @@ import qualified Control.Exception as E
 import           Control.Monad (MonadPlus(..))
 import           Control.Monad.Base (MonadBase)
 import           Control.Monad.Catch (MonadCatch, MonadThrow)
+import           Control.Monad.Error.Class (MonadError(..))
 import           Control.Monad.IO.Class (MonadIO(..))
 import UnliftIO (MonadUnliftIO(..))
 import           Control.Monad.Reader (MonadReader(..), ReaderT, asks)
@@ -169,6 +169,11 @@ data ActionEnv = Env { envReq       :: Request
 getResponse :: MonadIO m => ActionEnv -> m ScottyResponse
 getResponse ae = liftIO $ readTVarIO (envResponse ae)
 
+getResponseAction :: (MonadIO m) => ActionT m ScottyResponse
+getResponseAction = do
+  ae <- ask
+  getResponse ae
+
 modifyResponse :: (MonadIO m) => (ScottyResponse -> ScottyResponse) -> ActionT m ()
 modifyResponse f = do
   tv <- asks envResponse
@@ -207,6 +212,15 @@ defaultScottyResponse = SR status200 [] (ContentBuilder mempty)
 
 newtype ActionT m a = ActionT { runAM :: ReaderT ActionEnv m a }
   deriving newtype (Functor, Applicative, Monad, MonadIO, MonadReader ActionEnv, MonadTrans, MonadThrow, MonadCatch, MonadBase b, MonadBaseControl b, MonadTransControl, MonadUnliftIO)
+
+-- | Models the invariant that only 'StatusError's can be thrown and caught.
+instance (MonadUnliftIO m) => MonadError StatusError (ActionT m) where
+  throwError = E.throw
+  catchError = catch
+-- | Modeled after the behaviour in scotty < 0.20, 'fail' throws a 'StatusError' with code 500 ("Server Error"), which can be caught with 'E.catch' or 'rescue'.
+instance (MonadIO m) => MonadFail (ActionT m) where
+  fail = E.throw . StatusError status500 . pack
+-- | 'empty' throws 'ActionError' 'AENext', whereas '(<|>)' catches any 'ActionError's or 'StatusError's in the first action and proceeds to the second one.
 instance (MonadUnliftIO m) => Alternative (ActionT m) where
   empty = E.throw AENext
   a <|> b = do

Web/Scotty/Trans.hs

@@ -35,13 +35,15 @@ module Web.Scotty.Trans
       -- | Note: only one of these should be present in any given route
       -- definition, as they completely replace the current 'Response' body.
     , text, html, file, json, stream, raw, nested
+      -- ** Accessing the fields of the Response
+    , getResponseHeaders, getResponseStatus, getResponseContent
       -- ** Exceptions
     , raise, raiseStatus, throw, rescue, next, finish, defaultHandler, liftAndCatchIO
     , StatusError(..)
       -- * Parsing Parameters
     , Param, Parsable(..), readEither
       -- * Types
-    , RoutePattern, File, Kilobytes, ErrorHandler, Handler(..)
+    , RoutePattern, File, Content(..), Kilobytes, ErrorHandler, Handler(..)
       -- * Monad Transformers
     , ScottyT, ActionT
     , ScottyState, defaultScottyState
@@ -61,7 +63,7 @@ import Network.Wai.Handler.Warp (Port, runSettings, runSettingsSocket, setPort,
 
 import Web.Scotty.Action
 import Web.Scotty.Route
-import Web.Scotty.Internal.Types (ActionT(..), ScottyT(..), defaultScottyState, Application, RoutePattern, Options(..), defaultOptions, RouteOptions(..), defaultRouteOptions, ErrorHandler, Kilobytes, File, addMiddleware, setHandler, updateMaxRequestBodySize, routes, middlewares, ScottyException(..), ScottyState, defaultScottyState, StatusError(..))
+import Web.Scotty.Internal.Types (ActionT(..), ScottyT(..), defaultScottyState, Application, RoutePattern, Options(..), defaultOptions, RouteOptions(..), defaultRouteOptions, ErrorHandler, Kilobytes, File, addMiddleware, setHandler, updateMaxRequestBodySize, routes, middlewares, ScottyException(..), ScottyState, defaultScottyState, StatusError(..), Content(..))
 import Web.Scotty.Util (socketDescription)
 import Web.Scotty.Body (newBodyInfo)
 import Web.Scotty.Exceptions (Handler(..), catches)

changelog.md

@@ -1,8 +1,16 @@
 ## next [????.??.??]
 
-* remove dependencies on 'base-compat' and 'base-compat-batteries' (#318)
+* add getResponseHeaders, getResponseStatus, getResponseContent (#214)
 * add `captureParamMaybe`, `formParamMaybe`, `queryParamMaybe` (#322)
 
+## 0.20.1 [2023.10.03]
+
+* remove dependencies on 'base-compat' and 'base-compat-batteries' (#318)
+* re-add MonadFail (ActionT m) instance (#325)
+* re-add MonadError (ActionT m) instance, but the error type is now specialized to 'StatusError' (#325)
+* raise lower bound on base ( > 4.14 ) to reflect support for GHC >= 8.10 (#325).
+
+
 ## 0.20 [2023.10.02]
 * Drop support for GHC < 8.10 and modernise the CI pipeline (#300).
 * Adds a new `nested` handler that allows you to place an entire WAI Application under a Scotty route (#233).
@@ -15,8 +23,10 @@
 Breaking:
 
 * (#310) Introduce `unliftio` as a dependency, and base exception handling on `catch`.
-** Clarify the exception handling mechanism of ActionT, ScottyT. `rescue` changes signature to use proper `Exception` types rather than strings.
-** All ActionT methods (`text`, `html` etc.) have now a MonadIO constraint on the base monad rather than Monad because the response is constructed in a TVar inside ActionEnv. `rescue` has a MonadUnliftIO constraint. The Alternative instance of ActionT also is based on MonadUnliftIO because `<|>` is implemented in terms of `catch`. `ScottyT` and `ActionT` do not have an exception type parameter anymore.
+* (#310) Clarify the exception handling mechanism of ActionT, ScottyT. `rescue` changes signature to use proper `Exception` types rather than strings. Remove `ScottyError` typeclass.
+* (#310) All ActionT methods (`text`, `html` etc.) have now a MonadIO constraint on the base monad rather than Monad because the response is constructed in a TVar inside ActionEnv. `rescue` has a MonadUnliftIO constraint. The Alternative instance of ActionT also is based on MonadUnliftIO because `<|>` is implemented in terms of `catch`. `ScottyT` and `ActionT` do not have an exception type parameter anymore.
+* (#310) MonadError e (ActionT m) instance removed
+* (#310) MonadFail (ActionT m) instance is missing by mistake.
 
 ## 0.12.1 [2022.11.17]
 * Fix CPP bug that prevented tests from building on Windows.

scotty.cabal

@@ -1,5 +1,5 @@
 Name:                scotty
-Version:             0.20
+Version:             0.20.1
 Synopsis:            Haskell web framework inspired by Ruby's Sinatra, using WAI and Warp
 Homepage:            https://github.com/scotty-web/scotty
 Bug-reports:         https://github.com/scotty-web/scotty/issues
@@ -69,7 +69,7 @@ Library
                        Web.Scotty.Util
   default-language:    Haskell2010
   build-depends:       aeson                 >= 0.6.2.1  && < 2.3,
-                       base                  >= 4.6      && < 5,
+                       base                  >= 4.14     && < 5,
                        blaze-builder         >= 0.3.3.0  && < 0.5,
                        bytestring            >= 0.10.0.2 && < 0.12,
                        case-insensitive      >= 1.0.0.1  && < 1.3,

test/Web/ScottySpec.hs

@@ -141,6 +141,14 @@ spec = do
           get "/dictionary?word2=y" `shouldRespondWith` "y"
           get "/dictionary?word1=a&word2=b" `shouldRespondWith` "a"
 
+    context "MonadFail instance" $ do
+      withApp (Scotty.get "/" $ fail "boom!") $ do
+        it "returns 500 if not caught" $
+          get "/" `shouldRespondWith` 500
+      withApp (Scotty.get "/" $ (fail "boom!") `rescue` (\(_ :: StatusError) -> text "ok")) $
+        it "can catch the StatusError thrown by fail" $ do
+          get "/" `shouldRespondWith` 200 { matchBody = "ok"}
+
     describe "redirect" $ do
       withApp (
         do