Accept empty string as empty json body when calling an rpc (#832)

CHANGELOG.md

@@ -13,6 +13,7 @@ This project adheres to [Semantic Versioning](http://semver.org/).
 - #827, Avoid Warp reaper, extend socket timeout to 1 hour - @majorcode
 - #791, malformed nested JSON error - @diogob
 - Resource embedding in views referencing tables in public schema - @fab1an
+- #777, Empty body is allowed when calling a non-parameterized RPC - @koulakis
 - #831, Fix proc resource embedding issue with search_path - @steve-chavez
 
 ## [0.4.0.0] - 2017-01-19

src/PostgREST/ApiRequest.hs

@@ -13,6 +13,7 @@ module PostgREST.ApiRequest ( ApiRequest(..)
 
 import           Protolude
 import qualified Data.Aeson                as JSON
+import           Data.Aeson.Types          (emptyObject)
 import qualified Data.ByteString           as BS
 import qualified Data.ByteString.Internal  as BS (c2w)
 import qualified Data.ByteString.Lazy      as BL
@@ -124,13 +125,13 @@ userApiRequest schema req reqBody
   payload =
     case decodeContentType . fromMaybe "application/json" $ lookupHeader "content-type" of
       CTApplicationJSON ->
-          either Left (\val -> case ensureUniform (pluralize val) of
-            Nothing -> Left "All object keys must match"
-            Just json -> Right json) (JSON.eitherDecode reqBody)
+        note "All object keys must match" . ensureUniform . pluralize
+          =<< if BL.null reqBody && isTargetingProc
+               then Right emptyObject
+               else JSON.eitherDecode reqBody
       CTTextCSV ->
-          either Left (\val -> case ensureUniform (csvToJson val) of
-            Nothing -> Left "All lines must have same number of fields"
-            Just json -> Right json) (CSV.decodeByName reqBody)
+        note "All lines must have same number of fields" . ensureUniform . csvToJson
+          =<< CSV.decodeByName reqBody
       CTOther "application/x-www-form-urlencoded" ->
         Right . PayloadJSON . V.singleton . M.fromList
                     . map (toS *** JSON.String . toS) . parseSimpleQuery

test/Feature/QuerySpec.hs

@@ -5,6 +5,7 @@ import Test.Hspec.Wai
 import Test.Hspec.Wai.JSON
 import Network.HTTP.Types
 import Network.Wai.Test (SResponse(simpleHeaders,simpleStatus,simpleBody))
+import qualified Data.ByteString.Lazy as BL (empty)
 
 import SpecHelper
 import Text.Heredoc
@@ -481,7 +482,6 @@ spec = do
             , matchHeaders = ["Content-Range" <:> "0-0/2"]
             }
 
-
       it "returns proper json" $
         post "/rpc/getitemrange" [json| { "min": 2, "max": 4 } |] `shouldRespondWith`
           [json| [ {"id": 3}, {"id":4} ] |]
@@ -640,6 +640,12 @@ spec = do
                  , "boolean":"false", "date":"1900-01-01", "money":"$3.99", "enum":"foo" } |]
                  { matchHeaders = [matchContentTypeJson] }
 
+    context "a proc that receives no parameters" $
+      it "interprets empty string as empty json object on a post request" $
+        post "/rpc/noparamsproc" BL.empty `shouldRespondWith`
+          [json| "Return value of no parameters procedure." |]
+          { matchHeaders = [matchContentTypeJson] }
+
   describe "weird requests" $ do
     it "can query as normal" $ do
       get "/Escap3e;" `shouldRespondWith`

test/fixtures/schema.sql

@@ -173,6 +173,15 @@ CREATE FUNCTION getitemrange(min bigint, max bigint) RETURNS SETOF items
     SELECT * FROM test.items WHERE id > $1 AND id <= $2;
 $_$;
 
+--
+-- Name: version(); Type: FUNCTION; Schema: test; Owner: -
+--
+
+CREATE FUNCTION noparamsproc() RETURNS text
+	LANGUAGE sql
+	AS $$
+		SELECT a FROM (VALUES ('Return value of no parameters procedure.')) s(a);
+	$$;
 
 --
 -- Name: insert_insertable_view_with_join(); Type: FUNCTION; Schema: test; Owner: -