Akegalj/co 319/swagger account index (#3086)

* [CO-319] Fix account index swagger example

* [CO-319] Add roundtrip tests

* [CO-319] Fix recursive buildable instances

* [CO-319] Use strongly typed error

* [CO-319] Remove duplication in 'renderAccountIndexError'

* [CO-319] Distangle V1/Errors

This makes it now possible to import V1/Errors from the V1/Types module and leverage errors from this module.
One thing is still unclear to me: Why Errors isn't defined in V1/Types already?
There's a circular dependency between V1/Response and V1/Types if we go this way, as well as between
V1/Migration and V1/Types.
Nevertheless, it would make sense to have three data-types here:

- WalletError (defined in V1/Types)
- MigrationError (defined in V1/Types)
- JSONParsingError (defined in Response)

This way, we could remove the conflicting constructor from WalletError and remove the need for an
extra module here. It will also makes thing clearer

* [CO-319] Make V1/Error part of V1/Types

To realize this, we had to extract JSONValidationFailed and MigrationFailed constructor from WalletError.
They're now defined as constructor in different data-types (resp. JSONValidationError and MigrationError).

* [CO-319] Solve rebase conflicts

* [CO-319] Correctly format (jsend) newtype errors

This is rather ugly and could probably be achieved nicely with a better understanding of the
Generics.SOP library. As far as I could tell, there's no easy way to retrieve 'Tag' for single
constructor

(cf: 'For a datatype with a single constructor we do not need to tag values with their constructor; but for a datatype with multiple constructors we do.  ')

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

@@ -39,9 +39,10 @@ library
                        Cardano.Wallet.API.V1
                        Cardano.Wallet.API.V1.Accounts
                        Cardano.Wallet.API.V1.Addresses
-                       Cardano.Wallet.API.V1.Errors
                        Cardano.Wallet.API.V1.Generic
+                       Cardano.Wallet.API.V1.Errors
                        Cardano.Wallet.API.V1.Handlers
+                       Cardano.Wallet.API.V1.Headers
                        Cardano.Wallet.API.V1.Info
                        Cardano.Wallet.API.V1.LegacyHandlers
                        Cardano.Wallet.API.V1.LegacyHandlers.Accounts

wallet-new/integration/TransactionSpecs.hs

@@ -5,14 +5,14 @@ module TransactionSpecs (transactionSpecs) where
 
 import           Universum hiding (log)
 
-import           Cardano.Wallet.API.V1.Errors hiding (describe)
 import           Cardano.Wallet.Client.Http
+import           Control.Concurrent (threadDelay)
 import           Control.Lens
-import qualified Pos.Core as Core
 import           Test.Hspec
-
-import           Control.Concurrent (threadDelay)
 import           Text.Show.Pretty (ppShow)
+
+import qualified Pos.Core as Core
+
 import           Util
 
 {-# ANN module ("HLint: ignore Reduce duplication" :: Text) #-}

wallet-new/integration/WalletSpecs.hs

@@ -5,8 +5,8 @@ module WalletSpecs (walletSpecs) where
 
 import           Universum
 
+import           Cardano.Wallet.API.V1.Types (WalletError (WalletAlreadyExists))
 import           Cardano.Wallet.Client.Http
-import           Cardano.Wallet.API.V1.Errors (WalletError (WalletAlreadyExists))
 import           Control.Lens
 import           Test.Hspec
 

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

@@ -1,10 +1,12 @@
 {-# LANGUAGE DeriveFunctor   #-}
 {-# LANGUAGE DeriveGeneric   #-}
+{-# LANGUAGE LambdaCase      #-}
 {-# LANGUAGE OverloadedLists #-}
 module Cardano.Wallet.API.Response (
     Metadata (..)
   , ResponseStatus(..)
   , WalletResponse(..)
+  , JSONValidationError(..)
   -- * Generating responses for collections
   , respondWith
   -- * Generating responses for single resources
@@ -13,33 +15,37 @@ module Cardano.Wallet.API.Response (
   ) where
 
 import           Prelude
-import           Universum (Buildable, decodeUtf8, toText, (<>))
+import           Universum (Buildable, Exception, Text, decodeUtf8, toText, (<>))
 
+import           Cardano.Wallet.API.Indices (Indexable', IxSet')
+import           Cardano.Wallet.API.Request (RequestParams (..))
+import           Cardano.Wallet.API.Request.Filter (FilterOperations (..))
+import           Cardano.Wallet.API.Request.Pagination (Page (..), PaginationMetadata (..),
+                                                        PaginationParams (..), PerPage (..))
+import           Cardano.Wallet.API.Request.Sort (SortOperations (..))
+import           Cardano.Wallet.API.Response.Filter.IxSet as FilterBackend
 import           Cardano.Wallet.API.Response.JSend (ResponseStatus (..))
+import           Cardano.Wallet.API.Response.Sort.IxSet as SortBackend
+import           Cardano.Wallet.API.V1.Errors (ToServantError (..))
+import           Cardano.Wallet.API.V1.Generic (gparseJsend, gtoJsend)
 import           Control.Lens
 import           Data.Aeson
 import           Data.Aeson.Encode.Pretty (encodePretty)
 import           Data.Aeson.TH
-import qualified Data.Char as Char
 import           Data.Swagger as S
-import qualified Data.Text.Buildable
 import           Data.Typeable
 import           Formatting (bprint, build, (%))
+import           Generics.SOP.TH (deriveGeneric)
 import           GHC.Generics (Generic)
-import qualified Serokell.Aeson.Options as Serokell
+import           Servant (err400)
 import           Servant.API.ContentTypes (Accept (..), JSON, MimeRender (..), MimeUnrender (..),
                                            OctetStream)
 import           Test.QuickCheck
 
-import           Cardano.Wallet.API.Indices (Indexable', IxSet')
-import           Cardano.Wallet.API.Request (RequestParams (..))
-import           Cardano.Wallet.API.Request.Filter (FilterOperations (..))
-import           Cardano.Wallet.API.Request.Pagination (Page (..), PaginationMetadata (..),
-                                                        PaginationParams (..), PerPage (..))
-import           Cardano.Wallet.API.Request.Sort (SortOperations (..))
-import           Cardano.Wallet.API.Response.Filter.IxSet as FilterBackend
-import           Cardano.Wallet.API.Response.Sort.IxSet as SortBackend
-import           Cardano.Wallet.API.V1.Errors (WalletError (JSONValidationFailed))
+import qualified Data.Char as Char
+import qualified Data.Text.Buildable
+import qualified Serokell.Aeson.Options as Serokell
+
 
 -- | Extra information associated with an HTTP response.
 data Metadata = Metadata
@@ -136,7 +142,7 @@ respondWith :: (Monad m, Indexable' a)
             -> m (WalletResponse [a])
 respondWith RequestParams{..} fops sorts generator = do
     (theData, paginationMetadata) <- paginate rpPaginationParams . sortData sorts . applyFilters fops <$> generator
-    return $ WalletResponse {
+    return WalletResponse {
              wrData = theData
            , wrStatus = SuccessStatus
            , wrMeta = Metadata paginationMetadata
@@ -182,3 +188,37 @@ instance Accept ValidJSON where
 
 instance ToJSON a => MimeRender ValidJSON a where
     mimeRender _ = mimeRender (Proxy @ JSON)
+
+
+--
+-- Error from parsing / validating JSON inputs
+--
+
+newtype JSONValidationError
+    = JSONValidationFailed Text
+    deriving (Show, Eq)
+
+deriveGeneric ''JSONValidationError
+
+instance ToJSON JSONValidationError where
+    toJSON = gtoJsend ErrorStatus
+
+instance FromJSON JSONValidationError where
+    parseJSON = gparseJsend
+
+instance Exception JSONValidationError
+
+instance Arbitrary JSONValidationError where
+    arbitrary = oneof
+        [ pure $ JSONValidationFailed "JSON validation failed."
+        ]
+
+instance Buildable JSONValidationError where
+    build = \case
+        JSONValidationFailed _ ->
+            bprint "Couldn't decode a JSON input."
+
+instance ToServantError JSONValidationError where
+    declareServantError = \case
+        JSONValidationFailed _ ->
+            err400