Improve CLI tests to actually test the CLI functionality

tests/test_face_recognition.py

@@ -182,9 +182,20 @@ class Test_face_recognition(unittest.TestCase):
         self.assertEqual(type(match_results), list)
         self.assertListEqual(match_results, [])
 
-    def test_command_line_interface(self):
-        target_string = '--help  Show this message and exit.'
+    def test_command_line_interface_options(self):
+        target_string = '--help          Show this message and exit.'
         runner = CliRunner()
         help_result = runner.invoke(cli.main, ['--help'])
         self.assertEqual(help_result.exit_code, 0)
         self.assertTrue(target_string in help_result.output)
+
+    def test_command_line_interface(self):
+        target_string = 'obama.jpg,obama'
+        runner = CliRunner()
+        image_folder = os.path.join(os.path.dirname(__file__), 'test_images')
+        image_file = os.path.join(os.path.dirname(__file__), 'test_images', 'obama.jpg')
+
+        help_result = runner.invoke(cli.main, args=[image_folder, image_file])
+
+        self.assertEqual(help_result.exit_code, 0)
+        self.assertTrue(target_string in help_result.output)