Use ServantError to report Errors instead of String

This commit is contained in:
Timo von Holtz 2015-03-05 12:46:35 +11:00
parent 83aff1495b
commit ba46ecc0a9
4 changed files with 65 additions and 58 deletions

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@ -3,6 +3,7 @@
* Support content-type aware combinators and `Accept`/`Content-type` headers
* Added a lot of tests
* Support multiple concurrent threads
* Use `ServantError` to report Errors instead of `String`
0.2.2
-----

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@ -11,12 +11,12 @@
module Servant.Client
( client
, HasClient(..)
, ServantError(..)
, module Servant.Common.BaseUrl
) where
import Control.Monad
import Control.Monad.Trans.Either
import Data.Aeson
import Data.ByteString.Lazy (ByteString)
import Data.List
import Data.Proxy
@ -29,7 +29,6 @@ import Servant.API
import Servant.API.ContentTypes
import Servant.Common.BaseUrl
import Servant.Common.Req
import Servant.Common.Text
-- * Accessing APIs as a Client
@ -109,7 +108,7 @@ instance (KnownSymbol capture, ToText a, HasClient sublayout)
-- will just require an argument that specifies the scheme, host
-- and port to send the request to.
instance HasClient Delete where
type Client Delete = BaseUrl -> EitherT String IO ()
type Client Delete = BaseUrl -> EitherT ServantError IO ()
clientWithRoute Proxy req host =
void $ performRequest H.methodDelete req (== 204) host
@ -119,7 +118,7 @@ instance HasClient Delete where
-- will just require an argument that specifies the scheme, host
-- and port to send the request to.
instance (MimeUnrender ct result) => HasClient (Get (ct ': cts) result) where
type Client (Get (ct ': cts) result) = BaseUrl -> EitherT String IO result
type Client (Get (ct ': cts) result) = BaseUrl -> EitherT ServantError IO result
clientWithRoute Proxy req host =
performRequestCT (Proxy :: Proxy ct) H.methodGet req 200 host
@ -165,7 +164,7 @@ instance (KnownSymbol sym, ToText a, HasClient sublayout)
-- will just require an argument that specifies the scheme, host
-- and port to send the request to.
instance (MimeUnrender ct a) => HasClient (Post (ct ': cts) a) where
type Client (Post (ct ': cts) a) = BaseUrl -> EitherT String IO a
type Client (Post (ct ': cts) a) = BaseUrl -> EitherT ServantError IO a
clientWithRoute Proxy req uri =
performRequestCT (Proxy :: Proxy ct) H.methodPost req 201 uri
@ -175,7 +174,7 @@ instance (MimeUnrender ct a) => HasClient (Post (ct ': cts) a) where
-- will just require an argument that specifies the scheme, host
-- and port to send the request to.
instance (MimeUnrender ct a) => HasClient (Put (ct ': cts) a) where
type Client (Put (ct ': cts) a) = BaseUrl -> EitherT String IO a
type Client (Put (ct ': cts) a) = BaseUrl -> EitherT ServantError IO a
clientWithRoute Proxy req host =
performRequestCT (Proxy :: Proxy ct) H.methodPut req 200 host
@ -414,7 +413,7 @@ instance (KnownSymbol sym, HasClient sublayout)
-- | Pick a 'Method' and specify where the server you want to query is. You get
-- back the status code and the response body as a 'ByteString'.
instance HasClient Raw where
type Client Raw = H.Method -> BaseUrl -> EitherT String IO (Int, ByteString, MediaType)
type Client Raw = H.Method -> BaseUrl -> EitherT ServantError IO (Int, ByteString, MediaType)
clientWithRoute :: Proxy Raw -> Req -> Client Raw
clientWithRoute Proxy req httpMethod host =

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@ -27,6 +27,14 @@ import System.IO.Unsafe
import qualified Network.HTTP.Client as Client
data ServantError
= FailureResponse Status MediaType ByteString
| DecodeFailure String MediaType ByteString
| UnsupportedContentType MediaType ByteString
| ConnectionError HttpException
| InvalidContentTypeHeader String
deriving (Show)
data Req = Req
{ reqPath :: String
, qs :: QueryText
@ -109,7 +117,7 @@ displayHttpRequest :: Method -> String
displayHttpRequest httpmethod = "HTTP " ++ cs httpmethod ++ " request"
performRequest :: Method -> Req -> (Int -> Bool) -> BaseUrl -> EitherT String IO (Int, ByteString, MediaType)
performRequest :: Method -> Req -> (Int -> Bool) -> BaseUrl -> EitherT ServantError IO (Int, ByteString, MediaType)
performRequest reqMethod req isWantedStatus reqHost = do
partialRequest <- liftIO $ reqToRequest req reqHost
@ -118,43 +126,39 @@ performRequest reqMethod req isWantedStatus reqHost = do
}
eResponse <- liftIO $ __withGlobalManager $ \ manager ->
catchStatusCodeException $
catchHttpException $
Client.httpLbs request manager
case eResponse of
Left status ->
left (displayHttpRequest reqMethod ++ " failed with status: " ++ showStatus status)
Left err ->
left $ ConnectionError err
Right response -> do
let status = Client.responseStatus response
unless (isWantedStatus (statusCode status)) $
left (displayHttpRequest reqMethod ++ " failed with status: " ++ showStatus status)
body = Client.responseBody response
status_code = statusCode status
ct <- case lookup "Content-Type" $ Client.responseHeaders response of
Nothing -> pure $ "application"//"octet-stream"
Just t -> case parseAccept t of
Nothing -> left $ "invalid Content-Type header: " <> cs t
Nothing -> left . InvalidContentTypeHeader . cs $ t
Just t' -> pure t'
return (statusCode status, Client.responseBody response, ct)
where
showStatus (Status code message) =
show code ++ " - " ++ cs message
unless (isWantedStatus status_code) $
left $ FailureResponse status ct body
return (status_code, body, ct)
performRequestCT :: MimeUnrender ct result =>
Proxy ct -> Method -> Req -> Int -> BaseUrl -> EitherT String IO result
Proxy ct -> Method -> Req -> Int -> BaseUrl -> EitherT ServantError IO result
performRequestCT ct reqMethod req wantedStatus reqHost = do
let acceptCT = contentType ct
(_status, respBody, respCT) <-
performRequest reqMethod (req { reqAccept = [acceptCT] }) (== wantedStatus) reqHost
unless (matches respCT (acceptCT)) $
left $ "requested Content-Type " <> show acceptCT <> ", but got " <> show respCT
left $ UnsupportedContentType respCT respBody
either
(left . ((displayHttpRequest reqMethod ++ " returned invalid response of type" ++ show respCT) ++))
(left . (\s -> DecodeFailure s respCT respBody))
return
(fromByteString ct respBody)
catchStatusCodeException :: IO a -> IO (Either Status a)
catchStatusCodeException action =
catch (Right <$> action) $ \e ->
case e of
Client.StatusCodeException status _ _ -> return $ Left status
exc -> throwIO exc
catchHttpException :: IO a -> IO (Either HttpException a)
catchHttpException action =
catch (Right <$> action) (pure . Left)

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@ -8,6 +8,8 @@
{-# OPTIONS_GHC -fcontext-stack=25 #-}
module Servant.ClientSpec where
import Control.Applicative
import qualified Control.Arrow as Arrow
import Control.Concurrent
import Control.Exception
import Control.Monad.Trans.Either
@ -29,7 +31,6 @@ import Test.Hspec.QuickCheck
import Test.QuickCheck
import Servant.API
import Servant.API.ContentTypes
import Servant.Client
import Servant.Server
@ -110,21 +111,21 @@ server = serve api (
withServer :: (BaseUrl -> IO a) -> IO a
withServer action = withWaiDaemon (return server) action
getGet :: BaseUrl -> EitherT String IO Person
getDelete :: BaseUrl -> EitherT String IO ()
getCapture :: String -> BaseUrl -> EitherT String IO Person
getBody :: Person -> BaseUrl -> EitherT String IO Person
getQueryParam :: Maybe String -> BaseUrl -> EitherT String IO Person
getQueryParams :: [String] -> BaseUrl -> EitherT String IO [Person]
getQueryFlag :: Bool -> BaseUrl -> EitherT String IO Bool
getMatrixParam :: Maybe String -> BaseUrl -> EitherT String IO Person
getMatrixParams :: [String] -> BaseUrl -> EitherT String IO [Person]
getMatrixFlag :: Bool -> BaseUrl -> EitherT String IO Bool
getRawSuccess :: Method -> BaseUrl -> EitherT String IO (Int, ByteString, MediaType)
getRawFailure :: Method -> BaseUrl -> EitherT String IO (Int, ByteString, MediaType)
getGet :: BaseUrl -> EitherT ServantError IO Person
getDelete :: BaseUrl -> EitherT ServantError IO ()
getCapture :: String -> BaseUrl -> EitherT ServantError IO Person
getBody :: Person -> BaseUrl -> EitherT ServantError IO Person
getQueryParam :: Maybe String -> BaseUrl -> EitherT ServantError IO Person
getQueryParams :: [String] -> BaseUrl -> EitherT ServantError IO [Person]
getQueryFlag :: Bool -> BaseUrl -> EitherT ServantError IO Bool
getMatrixParam :: Maybe String -> BaseUrl -> EitherT ServantError IO Person
getMatrixParams :: [String] -> BaseUrl -> EitherT ServantError IO [Person]
getMatrixFlag :: Bool -> BaseUrl -> EitherT ServantError IO Bool
getRawSuccess :: Method -> BaseUrl -> EitherT ServantError IO (Int, ByteString, MediaType)
getRawFailure :: Method -> BaseUrl -> EitherT ServantError IO (Int, ByteString, MediaType)
getMultiple :: String -> Maybe Int -> Bool -> [(String, [Rational])]
-> BaseUrl
-> EitherT String IO (String, Maybe Int, Bool, [(String, [Rational])])
-> EitherT ServantError IO (String, Maybe Int, Bool, [(String, [Rational])])
( getGet
:<|> getDelete
:<|> getCapture
@ -143,32 +144,32 @@ getMultiple :: String -> Maybe Int -> Bool -> [(String, [Rational])]
spec :: Spec
spec = do
it "Servant.API.Get" $ withServer $ \ host -> do
runEitherT (getGet host) `shouldReturn` Right alice
(Arrow.left show <$> runEitherT (getGet host)) `shouldReturn` Right alice
it "Servant.API.Delete" $ withServer $ \ host -> do
runEitherT (getDelete host) `shouldReturn` Right ()
(Arrow.left show <$> runEitherT (getDelete host)) `shouldReturn` Right ()
it "Servant.API.Capture" $ withServer $ \ host -> do
runEitherT (getCapture "Paula" host) `shouldReturn` Right (Person "Paula" 0)
(Arrow.left show <$> runEitherT (getCapture "Paula" host)) `shouldReturn` Right (Person "Paula" 0)
it "Servant.API.ReqBody" $ withServer $ \ host -> do
let p = Person "Clara" 42
runEitherT (getBody p host) `shouldReturn` Right p
(Arrow.left show <$> runEitherT (getBody p host)) `shouldReturn` Right p
it "Servant.API.QueryParam" $ withServer $ \ host -> do
runEitherT (getQueryParam (Just "alice") host) `shouldReturn` Right alice
Left result <- runEitherT (getQueryParam (Just "bob") host)
result `shouldContain` "bob not found"
(Arrow.left show <$> runEitherT (getQueryParam (Just "alice") host)) `shouldReturn` Right alice
Left (FailureResponse s _ _) <- runEitherT (getQueryParam (Just "bob") host)
statusCode s `shouldBe` 400
it "Servant.API.QueryParam.QueryParams" $ withServer $ \ host -> do
runEitherT (getQueryParams [] host) `shouldReturn` Right []
runEitherT (getQueryParams ["alice", "bob"] host)
(Arrow.left show <$> runEitherT (getQueryParams [] host)) `shouldReturn` Right []
(Arrow.left show <$> runEitherT (getQueryParams ["alice", "bob"] host))
`shouldReturn` Right [Person "alice" 0, Person "bob" 1]
context "Servant.API.QueryParam.QueryFlag" $
forM_ [False, True] $ \ flag ->
it (show flag) $ withServer $ \ host -> do
runEitherT (getQueryFlag flag host) `shouldReturn` Right flag
(Arrow.left show <$> runEitherT (getQueryFlag flag host)) `shouldReturn` Right flag
{-
it "Servant.API.MatrixParam" $ withServer $ \ host -> do
@ -188,17 +189,19 @@ spec = do
-}
it "Servant.API.Raw on success" $ withServer $ \ host -> do
runEitherT (getRawSuccess methodGet host) `shouldReturn` Right (200, "rawSuccess", "application"//"octet-stream")
(Arrow.left show <$> runEitherT (getRawSuccess methodGet host))
`shouldReturn` Right (200, "rawSuccess", "application"//"octet-stream")
it "Servant.API.Raw on failure" $ withServer $ \ host -> do
runEitherT (getRawFailure methodGet host) `shouldReturn` Right (400, "rawFailure", "application"//"octet-stream")
(Arrow.left show <$> runEitherT (getRawFailure methodGet host))
`shouldReturn` Right (400, "rawFailure", "application"//"octet-stream")
modifyMaxSuccess (const 20) $ do
it "works for a combination of Capture, QueryParam, QueryFlag and ReqBody" $
property $ forAllShrink pathGen shrink $ \(NonEmpty cap) num flag body ->
ioProperty $ do
withServer $ \ host -> do
result <- runEitherT (getMultiple cap num flag body host)
result <- Arrow.left show <$> runEitherT (getMultiple cap num flag body host)
return $
result === Right (cap, num, flag, body)
@ -209,10 +212,10 @@ spec = do
it desc $
withWaiDaemon (return (serve api (left (500, "error message")))) $
\ host -> do
let getResponse :: BaseUrl -> EitherT String IO ()
let getResponse :: BaseUrl -> EitherT ServantError IO ()
getResponse = client api
Left result <- runEitherT (getResponse host)
result `shouldContain` "error message"
Left (FailureResponse status _ _) <- runEitherT (getResponse host)
status `shouldBe` (Status 500 "error message")
mapM_ test $
(WrappedApi (Proxy :: Proxy Delete), "Delete") :
(WrappedApi (Proxy :: Proxy (Get '[JSON] ())), "Delete") :
@ -222,7 +225,7 @@ spec = do
data WrappedApi where
WrappedApi :: (HasServer api, Server api ~ EitherT (Int, String) IO a,
HasClient api, Client api ~ (BaseUrl -> EitherT String IO ())) =>
HasClient api, Client api ~ (BaseUrl -> EitherT ServantError IO ())) =>
Proxy api -> WrappedApi