feat: prove and decode K1 realtime MQTT streams

tests/test_wifi_provisioning.py

@@ -0,0 +1,69 @@
+import pytest
+
+from k1link.ble.wifi_provisioning import (
+    FRAME_LENGTH,
+    build_wifi_provisioning_frame,
+    parse_wifi_status,
+)
+
+
+def test_build_wifi_provisioning_frame_layout() -> None:
+    frame = build_wifi_provisioning_frame("LabNet", "correct horse")
+
+    assert len(frame) == FRAME_LENGTH
+    assert frame[0] == 6
+    assert frame[1:7] == b"LabNet"
+    assert frame[7:33] == bytes(26)
+    assert frame[33] == 13
+    assert frame[34:47] == b"correct horse"
+    assert frame[47:98] == bytes(51)
+    assert frame[98] == 0
+
+
+def test_build_wifi_provisioning_frame_uses_utf8_byte_lengths() -> None:
+    frame = build_wifi_provisioning_frame("Сеть", "пароль")
+
+    assert frame[0] == len("Сеть".encode())
+    assert frame[33] == len("пароль".encode())
+
+
+@pytest.mark.parametrize(
+    ("ssid", "password", "message"),
+    [
+        ("", "password", "SSID must not be empty"),
+        ("network", "", "password must not be empty"),
+        ("x" * 33, "password", "at most 32 UTF-8 bytes"),
+        ("network", "x" * 65, "at most 64 UTF-8 bytes"),
+    ],
+)
+def test_build_wifi_provisioning_frame_rejects_invalid_lengths(
+    ssid: str,
+    password: str,
+    message: str,
+) -> None:
+    with pytest.raises(ValueError, match=message):
+        build_wifi_provisioning_frame(ssid, password)
+
+
+def test_parse_wifi_status_ap_baseline() -> None:
+    value = bytearray(54)
+    value[0] = 7
+    value[1:8] = b"WIFI_AP"
+    value[33] = 4
+    value[34:38] = bytes((192, 168, 56, 1))
+    value[50] = 1
+    value[52:54] = b"XX"
+
+    assert parse_wifi_status(bytes(value)) == {
+        "value_length": 54,
+        "mode": "WIFI_AP",
+        "ipv4": "192.168.56.1",
+        "status_code": 1,
+        "reserved": 0,
+        "trailer_hex": "5858",
+    }
+
+
+def test_parse_wifi_status_rejects_short_frame() -> None:
+    with pytest.raises(ValueError, match="at least 51 bytes"):
+        parse_wifi_status(bytes(50))