def test_asin_file(self):
     with self.assertRaises(ValueError):
         AmazonScraper.parse_args(['a', '--file', 'b'])
 def test_no_asins(self):
     with self.assertRaises(ValueError):
         AmazonScraper.parse_args([])
 def test_single_asin(self):
     args = AmazonScraper.parse_args(['a'])
     assert args.asin