Add some dummy tests to check all pg_wait_sampling functions

Author: ololobus

Diff for: expected/queries.out

@@ -20,6 +20,25 @@ WITH t as (SELECT sum(0) FROM pg_wait_sampling_profile)
    0
 (1 row)
 
+-- Some dummy checks just to be sure that all our functions work and return something.
+SELECT count(*) = 1 as test FROM pg_wait_sampling_get_current(pg_backend_pid());
+ test 
+------
+ t
+(1 row)
+
+SELECT count(*) > 5 as test FROM pg_wait_sampling_get_profile();
+ test 
+------
+ t
+(1 row)
+
+SELECT count(*) > 100 as test FROM pg_wait_sampling_get_history();
+ test 
+------
+ t
+(1 row)
+
 SELECT pg_wait_sampling_reset_profile();
  pg_wait_sampling_reset_profile 
 --------------------------------

Diff for: sql/queries.sql

@@ -9,6 +9,10 @@ WITH t as (SELECT sum(0) FROM pg_wait_sampling_history)
 WITH t as (SELECT sum(0) FROM pg_wait_sampling_profile)
 	SELECT sum(0) FROM generate_series(1, 2), t;
 
+-- Some dummy checks just to be sure that all our functions work and return something.
+SELECT count(*) = 1 as test FROM pg_wait_sampling_get_current(pg_backend_pid());
+SELECT count(*) > 5 as test FROM pg_wait_sampling_get_profile();
+SELECT count(*) > 100 as test FROM pg_wait_sampling_get_history();
 SELECT pg_wait_sampling_reset_profile();
 
 DROP EXTENSION pg_wait_sampling;