old_contents: import unittest
  import json
  
  from geopandas import GeoDataFrame
  
  class TestSeries(unittest.TestCase):
  
      def setUp(self):
          # Data from http://www.nyc.gov/html/dcp/download/bytes/nybb_13a.zip
          # saved as geopandas/examples/nybb_13a.zip.
          self.df = GeoDataFrame.from_file(
              '/nybb_13a/nybb.shp', vfs='zip://examples/nybb_13a.zip')
  
      def test_from_file_(self):
          self.assertTrue('geometry' in self.df)
          self.assertTrue(len(self.df) == 5)
      
      def test_to_json(self):
          text = self.df.to_json()
          data = json.loads(text)
          self.assertTrue(data['type'] == 'FeatureCollection')
          self.assertTrue(len(data['features']) == 5)
  
new_contents: import unittest
  import json
  import numpy as np
  
  from geopandas import GeoDataFrame
  
  class TestDataFrame(unittest.TestCase):
  
      def setUp(self):
          # Data from http://www.nyc.gov/html/dcp/download/bytes/nybb_13a.zip
          # saved as geopandas/examples/nybb_13a.zip.
          self.df = GeoDataFrame.from_file(
              '/nybb_13a/nybb.shp', vfs='zip://examples/nybb_13a.zip')
  
      def test_from_file_(self):
          self.assertTrue('geometry' in self.df)
          self.assertTrue(len(self.df) == 5)
          self.assertTrue(np.alltrue(self.df['BoroName'].values == np.array(['Staten Island',
                                     'Queens', 'Brooklyn', 'Manhattan', 'Bronx'])))
      
      def test_to_json(self):
          text = self.df.to_json()
          data = json.loads(text)
          self.assertTrue(data['type'] == 'FeatureCollection')
          self.assertTrue(len(data['features']) == 5)
  
subject: Add test for values of text columns in GeoDataFrame from file