test add type-check for the qr-printing

test/test_function_qr_non-native.py

@@ -0,0 +1,32 @@
+#!/usr/bin/python
+#  -*- coding: utf-8 -*-
+"""tests for the non-native part of qr()
+
+:author: `Patrick Kanzler <patrick.kanzler@fablab.fau.de>`_
+:organization: `python-escpos <https://github.com/python-escpos>`_
+:copyright: Copyright (c) 2016 `python-escpos <https://github.com/python-escpos>`_
+:license: GNU GPL v3
+"""
+
+from __future__ import absolute_import
+from __future__ import division
+from __future__ import print_function
+from __future__ import unicode_literals
+
+import mock
+
+from escpos.printer import Dummy
+from PIL import Image
+
+
+@mock.patch('escpos.printer.Dummy.image', spec=Dummy)
+def test_type_of_object_passed_to_image_function(img_function):
+    """
+    Test the type of object that is passed to the image function during non-native qr-printing.
+
+    The type should be PIL.Image
+    """
+    d = Dummy()
+    d.qr("LoremIpsum")
+    args, kwargs = img_function.call_args
+    assert isinstance(args[0], Image.Image)