ASCII.

Author: janiversen

pymodbus/message/ascii.py

@@ -45,7 +45,7 @@ def decode(self, data: bytes) -> tuple[int, int, int, bytes]:
                 used_len = start
             Log.debug("Garble data before frame: {}, skip until start of frame", data, ":hex")
             return used_len, 0, 0, self.EMPTY
-        if not (used_len := data.find(self.END)):
+        if (used_len := data.find(self.END)) == -1:
             Log.debug("Incomplete frame: {} wait for more data", data, ":hex")
             return 0, 0, 0, self.EMPTY
 

test/message/test_ascii.py

@@ -38,27 +38,24 @@ def test_roundtrip_LRC(self):
         assert MessageAscii.check_LRC(data, 0x1C)
 
     @pytest.mark.parametrize(
-        ("packet", "used_len", "id", "res"),
+        ("packet", "used_len", "res_id", "res"),
         [
             (b':010100010001FC\r\n', 17, 1, b'\x01\x00\x01\x00\x01'),
             (b':00010001000AF4\r\n', 17, 0, b'\x01\x00\x01\x00\x0a'),
             (b':01010001000AF3\r\n', 17, 1, b'\x01\x00\x01\x00\x0a'),
             (b':61620001000A32\r\n', 17, 97, b'\x62\x00\x01\x00\x0a'),
             (b':01270001000ACD\r\n', 17, 1, b'\x27\x00\x01\x00\x0a'),
+            (b':010100', 0, 0, b''), # short frame
+            (b':00010001000AF4', 0, 0, b''),
+            (b'abc:00010001000AF4', 3, 0, b''), # garble before frame
+            (b'abc00010001000AF4', 17, 0, b''), # only garble
+            (b':01010001000A00\r\n', 17, 0, b''),
         ],
     )
-    def test_decode(self, frame, packet, used_len, id, res):
+    def test_decode(self, frame, packet, used_len, res_id, res):
         """Test decode."""
         res_len, tid, dev_id, data = frame.decode(packet)
         assert res_len == used_len
         assert data == res
         assert not tid
-        assert dev_id == id
-
-
-    # NO: b':01270001000ACD\r\n'
-    # remember:
-    # -- split packet
-    # -- double packet
-    # -- garble data in front
-    # -- garble data after
+        assert dev_id == res_id