don't check if proc exists, just call it and return 400 if it does not

src/PostgREST/App.hs

@@ -186,22 +186,18 @@ app dbStructure conf apiRequest =
 
     (ActionInvoke, TargetProc qi,
      Just (PayloadJSON (UniformObjects payload))) -> do
-      exists <- H.query qi doesProcExist
-      if exists
-        then do
-          let p = V.head payload
-              jwtSecret = configJwtSecret conf
-          respondToRange $ do
-            row <- H.query () (callProc qi p topLevelRange shouldCount)
-            returnJWT <- H.query qi doesProcReturnJWT
-            let (tableTotal, queryTotal, body) = fromMaybe (Just 0, 0, emptyArray) row
-                (status, contentRange) = rangeHeader queryTotal tableTotal
-              in
-              return $ responseLBS status [jsonH, contentRange]
-                      (if returnJWT
-                      then "{\"token\":\"" <> cs (tokenJWT jwtSecret body) <> "\"}"
-                      else cs $ encode body)
-        else return notFound
+        let p = V.head payload
+            jwtSecret = configJwtSecret conf
+        respondToRange $ do
+          row <- H.query () (callProc qi p topLevelRange shouldCount)
+          returnJWT <- H.query qi doesProcReturnJWT
+          let (tableTotal, queryTotal, body) = fromMaybe (Just 0, 0, emptyArray) row
+              (status, contentRange) = rangeHeader queryTotal tableTotal
+            in
+            return $ responseLBS status [jsonH, contentRange]
+                    (if returnJWT
+                    then "{\"token\":\"" <> cs (tokenJWT jwtSecret body) <> "\"}"
+                    else cs $ encode body)
 
     (ActionRead, TargetRoot, Nothing) -> do
       let encodeApi ti = encodeOpenAPI ti host port

src/PostgREST/DbStructure.hs

@@ -6,7 +6,6 @@
 module PostgREST.DbStructure (
   getDbStructure
 , accessibleTables
-, doesProcExist
 , doesProcReturnJWT
 ) where
 
@@ -104,19 +103,6 @@ decodeSynonyms cols =
     <*> HD.value HD.text <*> HD.value HD.text
     <*> HD.value HD.text <*> HD.value HD.text
 
-doesProcExist :: H.Query QualifiedIdentifier Bool
-doesProcExist =
-  H.statement sql encodeQi (HD.singleRow (HD.value HD.bool)) True
- where
-  sql = [q| SELECT EXISTS (
-      SELECT 1
-      FROM   pg_catalog.pg_namespace n
-      JOIN   pg_catalog.pg_proc p
-      ON     pronamespace = n.oid
-      WHERE  nspname = $1
-      AND    proname = $2
-    ) |]
-
 doesProcReturnJWT :: H.Query QualifiedIdentifier Bool
 doesProcReturnJWT =
   H.statement sql encodeQi (HD.singleRow (HD.value HD.bool)) True

test/Feature/QuerySpec.hs

@@ -477,6 +477,11 @@ spec = do
         request methodPost "/rpc/sayhello"
           (acceptHdrs "application/json") "sdfsdf"
             `shouldRespondWith` 400
+      -- it used to be 404 and it makes sense but in another part we decided that it's good to return
+      -- PostgreSQL errors (and have the proxy handle them) and this saves us an aditional query on each rpc request
+      it "responds with 400 on an unexisting proc" $
+        post "/rpc/fake" [json| {} |] `shouldRespondWith` 400
+
 
     context "unsupported verbs" $ do
       it "DELETE fails" $