--- a/tests/test_grid.py	Sat Jun 24 12:03:39 2017 -0700
+++ b/tests/test_grid.py	Sat Jun 24 14:02:14 2017 -0700
@@ -4,18 +4,28 @@
 test that we can grid a solution
 """
 
+import os
 import unittest
+from common import datafile
 from globalneighbors.grid import LatLonGrid
+from globalneighbors.locations import locations
+from globalneighbors.read import read_city_list
+
 
 class TestGrid(unittest.TestCase):
     """test gridding functionality"""
 
+    ### test functions
+
     def test_dimensions(self):
 
         # make a 2 degree grid
         grid = LatLonGrid(90, 180)
         assert grid.n == (90, 180)
         assert grid.d == (2., 2.)
+        assert len(grid.grid) == 90
+        for row in grid.grid:
+            assert len(row) == 180
 
     def test_insertion(self):
 
@@ -25,7 +35,23 @@
         i, j = grid.index(*coord)
         assert i == 1
         assert j == 3
-        assert grid[(i,j)] == [1234]
+        assert grid[(i,j)] == set([1234])
+
+    def test_sample(self):
+
+        samplefile = datafile('sample.tsv')
+        assert os.path.exists(samplefile)
+        city_locations = locations(read_city_list(samplefile))
+        self.grid_locations(city_locations)
+
+    ### generic (utility) functions
+
+    def grid_locations(self, locations):
+        """grid locations + test created grid"""
+
+        grid = LatLonGrid(8, 8)
+        for geoid, (lat, lon) in locations.items():
+            grid.add(geoid, lat, lon)
 
 if __name__ == '__main__':
     unittest.main()