adding tests for _obs_searchtables

src/pg/test/sql/42_observatory_exploration_test.sql

@@ -0,0 +1,28 @@
+\i test/sql/load_fixtures.sql
+\pset format unaligned
+
+-- set up variables for use in testing
+
+\set cartodb_census_tract_geometry ''
+
+\set cartodb_county_geometry ''
+
+-- _OBS_SearchTables tests
+SELECT 
+  t.table_name IN ('obs_b0ef6dd68d5faddbf231fd7f02916b3d00ec43c4', 
+                   'obs_23da37d4e66e9de2f525572967f8618bde99a8c0') As _OBS_SearchTables_tables_match,
+  t.timespan = '2013' As _OBS_SearchTables_timespan_matches
+FROM cdb_observatory._OBS_SearchTables(
+  '"us.census.tiger".county',
+  '2013'
+) As t(table_name, timespan);
+
+-- _OBS_SearchTables tests
+-- should not return tables for year that does not match
+SELECT count(*) = 0 As _OBS_SearchTables_timespan_does_not_match
+FROM cdb_observatory._OBS_SearchTables(
+  '"us.census.tiger".county',
+  '1988' -- year before first tiger data was collected
+) As t(table_name, timespan);
+
+\i test/sql/drop_fixtures.sql