EnvelopeCodec message layer; scripts are thin business-API wrappers

tests/test_protocol.py

@@ -258,3 +258,35 @@ class TestLiveCaptures(unittest.TestCase):
             split_wire(b'{"cmdType":1101')
         with self.assertRaises(ValueError):
             decrypt_wire(b"not json at all")
+
+
+class TestEnvelopeCodec(unittest.TestCase):
+    def test_for_serial_roundtrip(self):
+        from franklinwh_agate_client.protocol.messages import EnvelopeCodec
+        codec = EnvelopeCodec.for_serial(SN)
+        self.assertEqual(codec.key, generate_secret_key(SN))
+        env = direct_connect_request(CommunicationCmd.BMS, SN,
+                                     data={"id": 1})
+        wire = codec.encode(env)
+        back = codec.decode(wire)
+        self.assertEqual(back.to_dict(), env.to_dict())
+
+    def test_decode_fixtures(self):
+        from franklinwh_agate_client.protocol.messages import EnvelopeCodec
+        disc = open(os.path.join(FIXTURES, "discovery_req.bin"),
+                    "rb").read()
+        info = open(os.path.join(FIXTURES, "device_info_reply.bin"),
+                    "rb").read()
+        self.assertEqual(
+            EnvelopeCodec.for_serial("").decode(disc).cmd_type, 1101)
+        reply = EnvelopeCodec.for_serial(SN).decode(info)
+        self.assertEqual(reply.cmd_type, 1102)
+        self.assertEqual(reply.to_dict()["dataArea"]["FHP_NUM"], 2)
+
+    def test_try_decode_none(self):
+        from franklinwh_agate_client.protocol.messages import EnvelopeCodec
+        codec = EnvelopeCodec.for_serial(SN)
+        self.assertIsNone(codec.try_decode(b""))
+        self.assertIsNone(codec.try_decode(b"not,a wire"))
+        with self.assertRaises(ValueError):
+            codec.decode(b"not,a wire")