From d1a8c3a6f88cfd70039a2810c49e932f2bca360e Mon Sep 17 00:00:00 2001
From: steve-chavez <stevechavezast@gmail.com>
Date: Sat, 7 Oct 2017 17:38:34 -0500
Subject: [PATCH] Fix #974 RPC error when function has single OUT param

---
 CHANGELOG.md                  |  1 +
 src/PostgREST/QueryBuilder.hs |  5 ++---
 test/Feature/RpcSpec.hs       | 19 +++++++++++++++++++
 test/fixtures/schema.sql      | 12 ++++++++++++
 4 files changed, 34 insertions(+), 3 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index cc694ab40..647ec3304 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -19,6 +19,7 @@ This project adheres to [Semantic Versioning](http://semver.org/).
 - #954, make OpenAPI rpc output dependent on user privileges - @steve-chavez
 - #955, Support configurable aud claim - @statik
 - #996, Fix embedded column conflicts table name - @grotsev
+- #974, Fix RPC error when function has single OUT param - @steve-chavez
 
 ## [0.4.3.0] - 2017-09-06
 
diff --git a/src/PostgREST/QueryBuilder.hs b/src/PostgREST/QueryBuilder.hs
index 9dc97336d..148eb787f 100644
--- a/src/PostgREST/QueryBuilder.hs
+++ b/src/PostgREST/QueryBuilder.hs
@@ -150,14 +150,14 @@ callProc qi params returnsScalar selectQuery countQuery _ countTotal isSingle pa
   where
     sql =
      if returnsScalar then [qc|
-       WITH {sourceCTEName} AS ({_callSql})
+       WITH {sourceCTEName} AS (select {fromQi qi}({_args}))
        SELECT
          {countResultF} AS total_result_set,
          1 AS page_total,
          {scalarBodyF} as body
        FROM ({selectQuery}) _postgrest_t;|]
      else [qc|
-       WITH {sourceCTEName} AS ({_callSql})
+       WITH {sourceCTEName} AS (select * from {fromQi qi}({_args}))
        SELECT
          {countResultF} AS total_result_set,
          pg_catalog.count(_postgrest_t) AS page_total,
@@ -170,7 +170,6 @@ callProc qi params returnsScalar selectQuery countQuery _ countTotal isSingle pa
                 else intercalate "," $ map _assignment (HM.toList params)
     _procName = qiName qi
     _assignment (n,v) = pgFmtIdent n <> ":=" <> insertableValue v
-    _callSql = [qc|select * from {fromQi qi}({_args}) |] :: Text
     decodeProc = HD.maybeRow procRow
     procRow = (,,) <$> HD.nullableValue HD.int8 <*> HD.value HD.int8
                    <*> HD.value HD.bytea
diff --git a/test/Feature/RpcSpec.hs b/test/Feature/RpcSpec.hs
index 43712c7d1..5e9959fc6 100644
--- a/test/Feature/RpcSpec.hs
+++ b/test/Feature/RpcSpec.hs
@@ -257,6 +257,25 @@ spec =
       get "/rpc/test" `shouldRespondWith`
         [json|[{"test":"hello","value":1}]|] { matchHeaders = [matchContentTypeJson] }
 
+    context "procs with OUT/INOUT params" $ do
+      it "returns a scalar result when there is a single OUT param" $ do
+        get "/rpc/single_out_param?num=5" `shouldRespondWith`
+          [json|6|] { matchHeaders = [matchContentTypeJson] }
+        get "/rpc/single_json_out_param?a=1&b=two" `shouldRespondWith`
+          [json|{"a": 1, "b": "two"}|] { matchHeaders = [matchContentTypeJson] }
+
+      it "returns a scalar result when there is a single INOUT param" $
+        get "/rpc/single_inout_param?num=2" `shouldRespondWith`
+          [json|3|] { matchHeaders = [matchContentTypeJson] }
+
+      it "returns a row result when there are many OUT params" $
+        get "/rpc/many_out_params" `shouldRespondWith`
+          [json|[{"my_json":{"a": 1, "b": "two"},"num":3,"str":"four"}]|] { matchHeaders = [matchContentTypeJson] }
+
+      it "returns a row result when there are many INOUT params" $
+        get "/rpc/many_inout_params?num=1&str=two" `shouldRespondWith`
+          [json| [{"num":1,"str":"two","b":true}]|] { matchHeaders = [matchContentTypeJson] }
+
     context "only for POST rpc" $ do
       context "expects a single json object" $ do
         it "does not expand posted json into parameters" $
diff --git a/test/fixtures/schema.sql b/test/fixtures/schema.sql
index a9a76f9ac..056e7f6d8 100755
--- a/test/fixtures/schema.sql
+++ b/test/fixtures/schema.sql
@@ -1273,10 +1273,22 @@ create table test.being_part (
   part int not null references test.part(part)
 );
 
+create function test.single_out_param(num int, OUT num_plus_one int) AS $$
+  select num + 1;
+$$ language sql;
+
+create function test.single_json_out_param(a int, b text, OUT my_json pg_catalog.json) AS $$
+  select json_build_object('a', a, 'b', b);
+$$ language sql;
+
 create function test.many_out_params(OUT my_json pg_catalog.json, OUT num int, OUT str text) AS $$
   select '{"a": 1, "b": "two"}'::json, 3, 'four'::text;
 $$ language sql;
 
+create function test.single_inout_param(INOUT num int) AS $$
+  select num + 1;
+$$ language sql;
+
 create function test.many_inout_params(INOUT num int, INOUT str text, INOUT b bool DEFAULT true) AS $$
   select num, str, b;
 $$ language sql;