added test coverage and fixed groupby

integrations/acquisition/covidcast/test_coverage_crossref_update.py

@@ -28,8 +28,9 @@ def localSetUp(self):
     self._db._cursor.execute('TRUNCATE TABLE `coverage_crossref`')
 
   @staticmethod
-  def _make_request():
-    params = {'geo': 'state:*'}
+  def _make_request(params=None):
+    if params is None:
+        params = {'geo': 'state:*'}
     response = requests.get(f"{Epidata.BASE_URL}/covidcast/geo_coverage", params=params, auth=Epidata.auth)
     response.raise_for_status()
     return response.json()
@@ -78,7 +79,25 @@ def test_caching(self):
 
     results = self._make_request()
 
-    # make sure the cache was actually served
+    # make sure the data was actually served
+    self.assertEqual(results, {
+      'result': 1,
+      'epidata': [{'signal': 'sig', 'source': 'src'}],
+      'message': 'success',
+    })
+
+    results = self._make_request(params = {'geo': 'hrr:*'})
+
+    # make sure the tables are empty
+    self.assertEqual(results, {
+      'result': -2,
+      'epidata': [],
+      'message': 'no results',
+    })
+
+    results = self._make_request(params = {'geo': 'state:pa'})
+
+    # make sure the data was actually served
     self.assertEqual(results, {
       'result': 1,
       'epidata': [{'signal': 'sig', 'source': 'src'}],

src/server/endpoints/covidcast.py

@@ -557,7 +557,7 @@ def handle_geo_coverage():
 
     q.apply_geo_filters("geo_type", "geo_value", geo_sets)
     q.set_sort_order("source", "signal")
-    q.group_by = fields_string # this condenses duplicate results, similar to `SELECT DISTINCT`
+    q.group_by = ["c." + field for field in fields_string] # this condenses duplicate results, similar to `SELECT DISTINCT`
 
     return execute_query(q.query, q.params, fields_string, [], [])