fix: no empty transaction on OPTIONS request

CHANGELOG.md

@@ -57,6 +57,7 @@ This project adheres to [Semantic Versioning](http://semver.org/).
  - #2341, The search path now correctly identifies schemas with uppercase and special characters in their names (regression) - @laurenceisla
  - #2364, "404 Not Found" on nested routes and "405 Method Not Allowed" errors no longer start an empty database transaction - @steve-chavez
  - #2342, Fix inaccurate result count when an inner embed was selected after a normal embed in the query string - @laurenceisla
+ - #2376, OPTIONS requests no longer start an empty database transaction - @steve-chavez
 
 ### Changed
 

src/PostgREST/App.hs

@@ -206,11 +206,14 @@ postgrestResponse conf@AppConfig{..} maybeDbStructure jsonDbS pgVer pool AuthRes
     liftEither . mapLeft Error.ApiRequestError $
       ApiRequest.userApiRequest conf dbStructure req body
 
-  let handleReq apiReq = handleRequest $ RequestContext conf dbStructure apiReq pgVer
+  let ctx apiReq = RequestContext conf dbStructure apiReq pgVer
 
-  runDbHandler pool (txMode apiRequest) (Just authRole /= configDbAnonRole) configDbPreparedStatements .
-    Middleware.optionalRollback conf apiRequest $
-      Middleware.runPgLocals conf authClaims authRole handleReq apiRequest jsonDbS pgVer
+  if iAction apiRequest == ActionInfo then
+    handleInfo (iTarget apiRequest) (ctx apiRequest)
+  else
+    runDbHandler pool (txMode apiRequest) (Just authRole /= configDbAnonRole) configDbPreparedStatements .
+      Middleware.optionalRollback conf apiRequest $
+        Middleware.runPgLocals conf authClaims authRole (handleRequest . ctx) apiRequest jsonDbS pgVer
 
 runDbHandler :: SQL.Pool -> SQL.Mode -> Bool -> Bool -> DbHandler a -> Handler IO a
 runDbHandler pool mode authenticated prepared handler = do
@@ -237,8 +240,6 @@ handleRequest context@(RequestContext _ _ ApiRequest{..} _) =
       handleSingleUpsert identifier context
     (ActionMutate MutationDelete, TargetIdent identifier) ->
       handleDelete identifier context
-    (ActionInfo, TargetIdent identifier) ->
-      handleInfo identifier context
     (ActionInvoke invMethod, TargetProc proc _) ->
       handleInvoke invMethod proc context
     (ActionInspect headersOnly, TargetDefaultSpec tSchema) ->
@@ -414,8 +415,8 @@ handleDelete identifier context@(RequestContext _ _ ApiRequest{..} _) = do
       else
         response HTTP.status204 [contentRangeHeader] mempty)
 
-handleInfo :: Monad m => QualifiedIdentifier -> RequestContext -> Handler m Wai.Response
-handleInfo identifier RequestContext{..} =
+handleInfo :: Monad m => Target -> RequestContext -> Handler m Wai.Response
+handleInfo target RequestContext{..} =
   case tbl of
     Just table ->
       return $ Wai.responseLBS HTTP.status200 [allOrigins, allowH table] mempty
@@ -423,7 +424,9 @@ handleInfo identifier RequestContext{..} =
       -- TODO is this right? When no tbl is found on the schema cache we disallow OPTIONS?
       throwError $ Error.ApiRequestError ApiRequestTypes.NotFound
   where
-    tbl = HM.lookup identifier (dbTables ctxDbStructure)
+    tbl = case target of
+      TargetIdent identifier -> HM.lookup identifier (dbTables ctxDbStructure)
+      _                      -> Nothing
     allOrigins = ("Access-Control-Allow-Origin", "*")
     allowH table =
       ( HTTP.hAllow

test/io/test_io.py

@@ -972,6 +972,33 @@ def test_no_pool_connection_required_on_bad_http_logic(defaultenv):
         assert response.status_code == 405
 
 
+def test_no_pool_connection_required_on_options(defaultenv):
+    "no pool connection should be consumed for OPTIONS requests"
+
+    env = {
+        **defaultenv,
+        "PGRST_DB_POOL": "1",
+    }
+
+    with run(env=env) as postgrest:
+        # First we retain the only pool connection available
+        # The try/except is a hack for not waiting for the response, taken from https://stackoverflow.com/a/45601591/4692662
+        try:
+            postgrest.session.get("/rpc/sleep?seconds=50", timeout=0.1)
+        except requests.exceptions.ReadTimeout:
+            pass
+
+        # Then the following OPTIONS requests should succeed rapidly
+
+        # OPTIONS on a table shouldn't require opening a connection
+        response = postgrest.session.options("/projects")
+        assert response.status_code == 200
+
+        # OPTIONS on RPC is not implemented yet, still it shouldn't require opening a connection
+        response = postgrest.session.options("/rpc/hello")
+        assert response.status_code == 405
+
+
 def test_no_pool_connection_required_on_bad_jwt_claim(defaultenv):
     "no pool connection should be consumed for failing on invalid jwt"