test new variant

tests/test_sweep_reader.py

@@ -66,6 +66,25 @@ def _pack_tty_point(step: int, ch1: int, ch2: int) -> bytes:
     )
 
 
+def _pack_tty_tagged_point(marker_word0: int, step: int, ch1: int, ch2: int) -> bytes:
+    return b"".join(
+        [
+            _u16le(marker_word0),
+            _u16le(step),
+            _u16le(ch1),
+            _u16le(ch2),
+        ]
+    )
+
+
+def _pack_tty_tagged_low(step: int, ch1: int, ch2: int) -> bytes:
+    return _pack_tty_tagged_point(0x00A3, step, ch1, ch2)
+
+
+def _pack_tty_tagged_high(step: int, ch1: int, ch2: int) -> bytes:
+    return _pack_tty_tagged_point(0x00A4, step, ch1, ch2)
+
+
 def _pack_logdet_point(step: int, value: int) -> bytes:
     return b"".join(
         [
@@ -166,6 +185,29 @@ class SweepReaderTests(unittest.TestCase):
             reader.join(timeout=1.0)
             stack.close()
 
+    def test_parser_16_bit_x2_falls_back_to_tty_do1_tagged_stream(self):
+        payload = bytearray()
+        while len(payload) < (_PARSER_16_BIT_X2_PROBE_BYTES + 40):
+            payload += _pack_tty_start()
+            payload += _pack_tty_tagged_low(1, 100, 90)
+            payload += _pack_tty_tagged_high(1, 120, 95)
+            payload += _pack_tty_tagged_low(2, 110, 80)
+            payload += _pack_tty_tagged_high(2, 130, 70)
+            payload += _pack_tty_tagged_low(1, 105, 85)
+
+        stack, reader, queue, stop_event, stderr = self._start_reader(bytes(payload), parser_16_bit_x2=True)
+        try:
+            sweep, info, aux = queue.get(timeout=2.0)
+            self.assertEqual(info["signal_kind"], "bin_iq_do1_tagged")
+            self.assertIsNone(aux)
+            self.assertIn("_do1_tagged_payload", info)
+            self.assertGreaterEqual(sweep.shape[0], 2)
+            self.assertIn("fallback -> legacy", stderr.getvalue())
+        finally:
+            stop_event.set()
+            reader.join(timeout=1.0)
+            stack.close()
+
     def test_parser_16_bit_x2_keeps_true_complex_stream(self):
         payload = b"".join(
             [