2 files changed, 49 insertions, 10 deletions

diff --git a/glucometerutils/drivers/otultraeasy.py b/glucometerutils/drivers/otultraeasy.py
index 323ebd7..3c0098a 100644
--- a/glucometerutils/drivers/otultraeasy.py
+++ b/glucometerutils/drivers/otultraeasy.py
@@ -92,6 +92,19 @@ _READING_RESPONSE = construct.Struct(
     'value' / construct.Int32ul,
 )
 
+def _make_packet(
+        message, sequence_number, expect_receive, acknowledge, disconnect):
+    return _PACKET.build(
+        {'data': {'value': {
+            'message': message,
+            'link_control': {
+                'sequence_number': sequence_number,
+                'expect_receive': expect_receive,
+                'acknowledge': acknowledge,
+                'disconnect': disconnect,
+            },
+        }}})
+
 class Device(serial.SerialDevice):
     BAUDRATE = 9600
     DEFAULT_CABLE_ID = '067b:2303'  # Generic PL2303 cable.
@@ -116,16 +129,12 @@ class Device(serial.SerialDevice):
         self.connect()
 
     def _send_packet(self, message, acknowledge=False, disconnect=False):
-        pkt = _PACKET.build(
-            {'data': {'value': {
-                'message': message,
-                'link_control': {
-                    'sequence_number': self.sent_counter_,
-                    'expect_receive': self.expect_receive_,
-                    'acknowledge': acknowledge,
-                    'disconnect': disconnect,
-                },
-            }}})
+        pkt = _make_packet(
+            message,
+            self.sent_counter_,
+            self.expect_receive_,
+            acknowledge,
+            disconnect)
         logging.debug('sending packet: %s', binascii.hexlify(pkt))
 
         self.serial_.write(pkt)
diff --git a/test/test_otultraeasy.py b/test/test_otultraeasy.py
new file mode 100644
index 0000000..6d802db
--- /dev/null
+++ b/test/test_otultraeasy.py
@@ -0,0 +1,30 @@
+# -*- coding: utf-8 -*-
+"""Tests for the LifeScan OneTouch Ultra Easy driver."""
+
+__author__ = 'Diego Elio Pettenò'
+__email__ = 'flameeyes@flameeyes.eu'
+__copyright__ = 'Copyright © 2018, Diego Elio Pettenò'
+__license__ = 'MIT'
+
+# pylint: disable=protected-access,missing-docstring
+
+from absl.testing import absltest
+
+from glucometerutils.drivers import otultraeasy
+
+
+class ConstructTest(absltest.TestCase):
+
+    def test_make_packet_ack(self):
+        self.assertEqual(
+            b'\x02\x06\x08\x03\xc2\x62',
+            otultraeasy._make_packet(b'', False, False, False, True))
+
+    def test_make_packet_version_request(self):
+        self.assertEqual(
+            b'\x02\x09\x03\x05\x0d\x02\x03\x08\x9f',
+            otultraeasy._make_packet(
+                b'\x05\x0d\x02', True, True, False, False))
+
+if __name__ == '__main__':
+    absltest.main()