CREATE SERVER testserver
FOREIGN DATA WRAPPER rdf_fdw 
OPTIONS (    
  endpoint 'https://dbpedia.org/sparql'
);
CREATE USER u1;
/* empty user name */
CREATE USER MAPPING FOR u1 SERVER testserver OPTIONS (user '', password 'foo');
ERROR:  empty value in option 'user'
/* empty password */
CREATE USER MAPPING FOR u1 SERVER testserver OPTIONS (user 'foo', password '');
ERROR:  empty value in option 'password'
/* invalid option */
CREATE USER MAPPING FOR u1 SERVER testserver OPTIONS (user 'jim', foo 'bar');
ERROR:  invalid rdf_fdw option 'foo'
/* clean up */
DROP SERVER testserver CASCADE;
DROP USER u1;