Add decoder tests (#344)

tests/test__frame_helper.py

@@ -0,0 +1,62 @@
+import asyncio
+from unittest.mock import MagicMock
+
+import pytest
+
+from aioesphomeapi._frame_helper import APIPlaintextFrameHelper
+from aioesphomeapi.util import varuint_to_bytes
+
+PREAMBLE = b"\x00"
+
+
+@pytest.mark.asyncio
+@pytest.mark.parametrize(
+    "in_bytes, pkt_data, pkt_type",
+    [
+        (PREAMBLE + varuint_to_bytes(0) + varuint_to_bytes(1), b"", 1),
+        (
+            PREAMBLE + varuint_to_bytes(192) + varuint_to_bytes(1) + (b"\x42" * 192),
+            (b"\x42" * 192),
+            1,
+        ),
+        (
+            PREAMBLE + varuint_to_bytes(192) + varuint_to_bytes(100) + (b"\x42" * 192),
+            (b"\x42" * 192),
+            100,
+        ),
+        (
+            PREAMBLE + varuint_to_bytes(4) + varuint_to_bytes(100) + (b"\x42" * 4),
+            (b"\x42" * 4),
+            100,
+        ),
+        (
+            PREAMBLE
+            + varuint_to_bytes(8192)
+            + varuint_to_bytes(8192)
+            + (b"\x42" * 8192),
+            (b"\x42" * 8192),
+            8192,
+        ),
+        (
+            PREAMBLE + varuint_to_bytes(256) + varuint_to_bytes(256) + (b"\x42" * 256),
+            (b"\x42" * 256),
+            256,
+        ),
+    ],
+)
+async def test_plaintext_frame_helper(in_bytes, pkt_data, pkt_type):
+
+    stream_reader = asyncio.StreamReader()
+    stream_writer = MagicMock()
+
+    for _ in range(5):
+
+        stream_reader.feed_data(in_bytes)
+
+        helper = APIPlaintextFrameHelper(stream_reader, stream_writer)
+
+        async with helper.read_lock:
+            pkt = await helper.read_packet_with_lock()
+
+        assert pkt.type == pkt_type
+        assert pkt.data == pkt_data