Throw an explicit error about NVRAM corruption when it is detected (#218)

Author: puddly

tests/api/test_network_state.py

@@ -2,8 +2,10 @@
 from unittest import mock
 
 import pytest
+from zigpy.exceptions import FormationFailure
 
 import zigpy_znp.types as t
+import zigpy_znp.commands as c
 from zigpy_znp.types.nvids import ExNvIds, OsalNvIds
 
 from ..conftest import (
@@ -114,3 +116,33 @@ async def test_write_settings_fast(device, make_connected_znp):
 
     # We don't waste time writing device info
     assert len(mock_write_devices.mock_awaits) == 0
+
+
+@pytest.mark.parametrize("device", FORMED_DEVICES)
+async def test_formation_failure_on_corrupted_nvram(device, make_connected_znp):
+    formed_znp, _ = await make_connected_znp(server_cls=FormedLaunchpadCC26X2R1)
+    await formed_znp.load_network_info()
+    formed_znp.close()
+
+    znp, znp_server = await make_connected_znp(server_cls=device)
+
+    # Instead of accepting the write, fail
+    write_reset_rsp = znp_server.reply_once_to(
+        request=c.SYS.OSALNVWriteExt.Req(
+            Id=OsalNvIds.STARTUP_OPTION,
+            Offset=0,
+            Value=t.ShortBytes(
+                (t.StartupOptions.ClearState | t.StartupOptions.ClearConfig).serialize()
+            ),
+        ),
+        responses=[c.SYS.OSALNVWriteExt.Rsp(Status=t.Status.NV_OPER_FAILED)],
+        override=True,
+    )
+
+    with pytest.raises(FormationFailure):
+        await znp.write_network_info(
+            network_info=formed_znp.network_info,
+            node_info=formed_znp.node_info,
+        )
+
+    await write_reset_rsp

zigpy_znp/api.py

@@ -344,8 +344,19 @@ async def write_network_info(
         """
         from zigpy_znp.znp import security
 
-        if not network_info.stack_specific.get("form_quickly", False):
-            await self.reset_network_info()
+        try:
+            if not network_info.stack_specific.get("form_quickly", False):
+                await self.reset_network_info()
+        except InvalidCommandResponse as rsp:
+            if rsp.response.Status != t.Status.NV_OPER_FAILED:
+                raise
+
+            # Sonoff Zigbee 3.0 USB Dongle Plus coordinators randomly fail with NVRAM
+            # corruption. This seemingly can only be fixed by re-flashing the firmware.
+            raise zigpy.exceptions.FormationFailure(
+                "Network formation failed: NVRAM is corrupted, re-flash your adapter's"
+                " firmware."
+            )
 
         # Form a network with completely random settings to get NVRAM to a known state
         for item, value in {