[CO-417] Add more friendly 415 Unsupported Media Type error

[CO-417] stack2nix patch

[CO-417] Introducing UnsupportedMimeTypeError and delegating code to middleware

[CO-417] Small improvements and CHANGELOG entry

Author: paweljakubas

CHANGELOG.md

@@ -21,10 +21,10 @@
 
 - We can force an NTP-check when getting node-info via the API (`?force_ntp_check` query flag) (CO-325)
 
-- The API provides an endpoint to retrieve basic statistics on the UTxO distribution of a wallet 
+- The API provides an endpoint to retrieve basic statistics on the UTxO distribution of a wallet
   (`/api/v1/wallets/{walletId}/statistics`). (CO-325)
 
-- cardano-sl exposes a new package `x509` with tooling for defining a PKI infrastructure from 
+- cardano-sl exposes a new package `x509` with tooling for defining a PKI infrastructure from
   pure Haskell. This is basically an export of the internals of the tool `cardano-sl-x509-generate` (CO-387)
 
 
@@ -50,8 +50,8 @@
 - **[API BREAKING CHANGE]** The behavior of `/api/v1/addresses/{address}` has been adjusted to reflect more accurately
   the meaning of ownership regarding addresses.
   The previous version of this endpoint failed with an HTTP error when the given address was unknown to the wallet.
-  This was misleading since an address that is unknown to the wallet may still belong to the wallet. To reflect this, 
-  the V1 endpoint does not fail anymore as it used to when an address is not recognised and returns instead a new field 
+  This was misleading since an address that is unknown to the wallet may still belong to the wallet. To reflect this,
+  the V1 endpoint does not fail anymore as it used to when an address is not recognised and returns instead a new field
   'is-ours' which indicates either that an address is ours, or that it is 'not-recognised'. (CBR-401)
 
 ### Improvements
@@ -62,13 +62,15 @@
 
 - Small refactor of wallet Errors implementation to be more maintainable (CBR-26)
 
-- Content-Type parser is now more lenient and accepts `application/json`, `application/json;charset=utf-8` and 
+- Content-Type parser is now more lenient and accepts `application/json`, `application/json;charset=utf-8` and
   no Content-Type at all (defaulting to `application/json`).
 
 - The codebase now relies on the package `cryptonite` (instead of `ed25519`) for Ed25519 implementation (CO-325)
 
 - **[API BREAKING CHANGE]** Improve diagnostic for `NotEnoughMoney` error (CBR-461)
 
+- When Content-Type's main MIME-type cannot fall back to 'application/json' then UnsupportedMimeTypeError is returned
+
 ### Specifications
 
 ### Documentation

pkgs/default.nix

@@ -18051,6 +18051,7 @@ license = stdenv.lib.licenses.mit;
 , beam-migrate
 , beam-sqlite
 , bifunctors
+, binary
 , bytestring
 , cardano-crypto
 , cardano-sl
@@ -18176,6 +18177,7 @@ beam-core
 beam-migrate
 beam-sqlite
 bifunctors
+binary
 bytestring
 cardano-crypto
 cardano-sl

wallet-new/cardano-sl-wallet-new.cabal

@@ -167,6 +167,7 @@ library
   ghc-options:         -Wall
 
   build-depends:       base
+                     , binary
                      , acid-state
                      , aeson
                      , aeson-options

wallet-new/src/Cardano/Wallet/API/Response.hs

@@ -7,6 +7,7 @@ module Cardano.Wallet.API.Response (
   , ResponseStatus(..)
   , WalletResponse(..)
   , JSONValidationError(..)
+  , UnsupportedMimeTypeError(..)
   -- * Generating responses for collections
   , respondWith
   , fromSlice
@@ -34,7 +35,7 @@ import           Formatting (bprint, build, (%))
 import qualified Formatting.Buildable
 import           Generics.SOP.TH (deriveGeneric)
 import           GHC.Generics (Generic)
-import           Servant (err400)
+import           Servant (err400, err415)
 import           Servant.API.ContentTypes (Accept (..), JSON, MimeRender (..),
                      MimeUnrender (..), OctetStream)
 import           Test.QuickCheck
@@ -269,3 +270,36 @@ instance HasDiagnostic JSONValidationError where
 instance ToServantError JSONValidationError where
     declareServantError _ =
         err400
+
+
+newtype UnsupportedMimeTypeError
+    = UnsupportedMimeTypePresent Text
+    deriving (Eq, Show, Generic)
+
+deriveGeneric ''UnsupportedMimeTypeError
+
+instance ToJSON UnsupportedMimeTypeError where
+    toJSON =
+        jsendErrorGenericToJSON
+
+instance FromJSON UnsupportedMimeTypeError where
+    parseJSON =
+        jsendErrorGenericParseJSON
+
+instance Exception UnsupportedMimeTypeError
+
+instance Arbitrary UnsupportedMimeTypeError where
+    arbitrary =
+        pure (UnsupportedMimeTypePresent "Delivered MIME-type is not supported.")
+
+instance Buildable UnsupportedMimeTypeError where
+    build (UnsupportedMimeTypePresent txt) =
+        bprint build txt
+
+instance HasDiagnostic UnsupportedMimeTypeError where
+    getDiagnosticKey _ =
+        "mimeContentTypeError"
+
+instance ToServantError UnsupportedMimeTypeError where
+    declareServantError _ =
+        err415

wallet-new/src/Cardano/Wallet/API/V1/Swagger.hs

@@ -376,6 +376,9 @@ $errors
     -- 'JSONValidationError'
     , mkRow fmtErr $ JSONValidationFailed "Expected String, found Null."
 
+    -- 'UnsupportedMimeTypeError'
+    , mkRow fmtErr $ UnsupportedMimeTypePresent "Expected Content-Type's main MIME-type to be 'application/json'."
+
     -- TODO 'MnemonicError' ?
     ]
   mkRow fmt err = T.intercalate "|" (fmt err)
@@ -860,8 +863,8 @@ curl -X POST \
   --cacert ./scripts/tls-files/ca.crt \
   --cert ./scripts/tls-files/client.pem \
   -d '{
-	"walletId": "Ae2tdPwUPE...V3AVTnqGZ4",
-	"accountIndex": 2147483648
+        "walletId": "Ae2tdPwUPE...V3AVTnqGZ4",
+        "accountIndex": 2147483648
 }'
 ```
 

wallet-new/src/Cardano/Wallet/Action.hs

@@ -29,7 +29,7 @@ import           Cardano.Wallet.Server.CLI (NewWalletBackendParams,
                      getFullMigrationFlag, getWalletDbOptions, walletDbPath,
                      walletRebuildDb)
 import           Cardano.Wallet.Server.Middlewares (throttleMiddleware,
-                     withDefaultHeader)
+                     unsupportedMimeTypeMiddleware, withDefaultHeader)
 import qualified Cardano.Wallet.Server.Plugins as Plugins
 import           Cardano.Wallet.WalletLayer (PassiveWalletLayer)
 import qualified Cardano.Wallet.WalletLayer.Kernel as WalletLayer.Kernel
@@ -88,6 +88,7 @@ actionWithWallet params genesisConfig walletConfig txpConfig ntpConfig nodeParam
                 -- Throttle requests.
                 [ throttleMiddleware (ccThrottle walletConfig)
                 , withDefaultHeader Headers.applicationJson
+                , unsupportedMimeTypeMiddleware
                 ])
 
             -- The corresponding wallet documention, served as a different

wallet-new/src/Cardano/Wallet/Server/Middlewares.hs

@@ -7,18 +7,25 @@ module Cardano.Wallet.Server.Middlewares
     ( withMiddlewares
     , throttleMiddleware
     , withDefaultHeader
+    , unsupportedMimeTypeMiddleware
     ) where
 
-import           Universum
+import           Universum hiding (toStrict)
 
 import           Data.Aeson (encode)
+import           Data.Binary.Builder (fromByteString)
+import           Data.ByteString.Lazy (toStrict)
 import qualified Data.List as List
 import           Network.HTTP.Types.Header (Header)
 import           Network.HTTP.Types.Method (methodPatch, methodPost, methodPut)
-import           Network.Wai (Application, Middleware, ifRequest,
-                     requestHeaders, requestMethod, responseLBS)
+import           Network.HTTP.Types.Status (status415)
+import           Network.Wai (Application, Middleware, Response, ifRequest,
+                     modifyResponse, requestHeaders, requestMethod,
+                     responseBuilder, responseLBS, responseStatus)
 import qualified Network.Wai.Middleware.Throttle as Throttle
 
+
+import           Cardano.Wallet.API.Response (UnsupportedMimeTypeError (..))
 import           Cardano.Wallet.API.V1.Headers (applicationJson)
 import qualified Cardano.Wallet.API.V1.Types as V1
 
@@ -29,6 +36,23 @@ import           Pos.Launcher.Configuration (ThrottleSettings (..))
 withMiddlewares :: [Middleware] -> Application -> Application
 withMiddlewares = flip $ foldr ($)
 
+unsupportedMimeTypeMiddleware :: Middleware
+unsupportedMimeTypeMiddleware =
+    modifyResponse responseModifier
+  where
+      responseModifier :: Response -> Response
+      responseModifier r
+          | responseStatus r == status415 =
+            responseBuilder status415
+            [ ("Content-Type", "application/json") ]
+            ( fromByteString .
+              toStrict .
+              encode $
+              UnsupportedMimeTypePresent "The API expects the Content-Type's main MIME-type to be 'application/json'"
+            )
+          | otherwise = r
+
+
 -- | Only apply a @Middleware@ to request with bodies (we don't consider
 -- "DELETE" as one of them).
 ifRequestWithBody :: Middleware -> Middleware

wallet-new/test/MarshallingSpec.hs

@@ -40,7 +40,8 @@ import           Test.Pos.Core.Arbitrary ()
 
 import           Cardano.Wallet.API.Indices
 import           Cardano.Wallet.API.Request.Pagination (Page, PerPage)
-import           Cardano.Wallet.API.Response (JSONValidationError)
+import           Cardano.Wallet.API.Response (JSONValidationError,
+                     UnsupportedMimeTypeError)
 import           Cardano.Wallet.API.V1.Migration.Types (Migrate (..),
                      MigrationError)
 import           Cardano.Wallet.API.V1.Types
@@ -75,6 +76,7 @@ spec = parallel $ describe "Marshalling & Unmarshalling" $ do
         aesonRoundtripProp @TransactionStatus Proxy
         aesonRoundtripProp @WalletError Proxy
         aesonRoundtripProp @JSONValidationError Proxy
+        aesonRoundtripProp @UnsupportedMimeTypeError Proxy
         aesonRoundtripProp @MigrationError Proxy
         aesonRoundtripProp @WalletId Proxy
         aesonRoundtripProp @Wallet Proxy

wallet-new/test/WalletNewJson.hs

@@ -6,7 +6,8 @@ import           Universum
 
 import           Hedgehog (Property)
 
-import           Cardano.Wallet.API.Response (JSONValidationError (..))
+import           Cardano.Wallet.API.Response (JSONValidationError (..),
+                     UnsupportedMimeTypeError (..))
 import           Cardano.Wallet.API.V1.Migration.Types (MigrationError (..))
 import           Cardano.Wallet.API.V1.Swagger.Example (genExample)
 import           Cardano.Wallet.API.V1.Types (ErrNotEnoughMoney (..), V1 (..),
@@ -165,3 +166,12 @@ golden_JSONValidationError_JSONValidationFailed =
     goldenTestJSON
         (JSONValidationFailed "test")
             "test/golden/JSONValidationError_JSONValidationFailed"
+
+-------------------------------------------------------------------------------
+-- UnsupportedMimeTypeError
+-------------------------------------------------------------------------------
+golden_UnsupportedMimeTypeError_UnsupportedMimeTypePresent :: Property
+golden_UnsupportedMimeTypeError_UnsupportedMimeTypePresent =
+    goldenTestJSON
+        (UnsupportedMimeTypePresent "test")
+            "test/golden/UnsupportedMimeTypeError_UnsupportedMimeTypePresent"

wallet-new/test/golden/UnsupportedMimeTypeError_UnsupportedMimeTypePresent

@@ -0,0 +1 @@
+{"status":"error","diagnostic":{"mimeContentTypeError":"test"},"message":"UnsupportedMimeTypePresent"}