Fix json test by creating a schema.

It's been failing since HEAD introduced built-in json type.  The solution is simply creating a schema and put the domain in it.

Author: umitanuki

expected/json.out

@@ -1,3 +1,4 @@
+CREATE SCHEMA plv8;
 CREATE FUNCTION valid_json(json text) RETURNS boolean
 LANGUAGE plv8 IMMUTABLE STRICT
 AS $$
@@ -8,9 +9,9 @@ AS $$
     return false;
   }
 $$;
-CREATE DOMAIN json AS text
+CREATE DOMAIN plv8.json AS text
         CONSTRAINT json_check CHECK (valid_json(VALUE));
-CREATE FUNCTION get_key(key text, json_raw text) RETURNS json
+CREATE FUNCTION get_key(key text, json_raw text) RETURNS plv8.json
 LANGUAGE plv8 IMMUTABLE STRICT
 AS $$
   var val = JSON.parse(json_raw)[key];
@@ -19,7 +20,7 @@ AS $$
   return JSON.stringify(ret);
 $$;
 CREATE TABLE jsononly (
-    data json
+    data plv8.json
 );
 COPY jsononly (data) FROM stdin;
 -- Call twice to test the function cache.

sql/json.sql

@@ -1,3 +1,4 @@
+CREATE SCHEMA plv8;
 CREATE FUNCTION valid_json(json text) RETURNS boolean
 LANGUAGE plv8 IMMUTABLE STRICT
 AS $$
@@ -9,10 +10,10 @@ AS $$
   }
 $$;
 
-CREATE DOMAIN json AS text
+CREATE DOMAIN plv8.json AS text
         CONSTRAINT json_check CHECK (valid_json(VALUE));
 
-CREATE FUNCTION get_key(key text, json_raw text) RETURNS json
+CREATE FUNCTION get_key(key text, json_raw text) RETURNS plv8.json
 LANGUAGE plv8 IMMUTABLE STRICT
 AS $$
   var val = JSON.parse(json_raw)[key];
@@ -22,7 +23,7 @@ AS $$
 $$;
 
 CREATE TABLE jsononly (
-    data json
+    data plv8.json
 );
 
 COPY jsononly (data) FROM stdin;