Fix encryption disconnect race

[bdraco]

replaces and closes #354

should fix the issue in home-assistant/core#142316 (comment)

[codecov]

Codecov Report

Attention: Patch coverage is 74.54545% with 14 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
switchbot/devices/device.py	74.54%	14 Missing ⚠️

Files with missing lines	Coverage Δ
switchbot/devices/device.py	57.72% <74.54%> (+15.32%)	⬆️

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[Copilot]

Pull Request Overview

This PR refactors command sending and encryption initialization to avoid race conditions during disconnect by introducing an operation lock and a unified retry helper.

• Introduces _send_command_locked_with_retry and updates _send_command to use it under self._operation_lock.
• Ensures encryption is initialized inside the lock and adds guard clauses for IV state.
• Clears encryption state under a connect lock during disconnect.

Reviewed Changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.

File	Description
tests/test_encrypted_device.py	Adds tests for the new locking behavior, encryption init, and race handling on disconnect
switchbot/devices/device.py	Refactors _send_command, adds _send_command_locked_with_retry, strengthens encryption init, and updates disconnect logic

Comments suppressed due to low confidence (2)

switchbot/devices/device.py:206

• The parameter 'retry' is not used in this method and can be removed to simplify the signature and avoid confusion.

async def _send_command_locked_with_retry(self, key: str, command: bytes, retry: int, max_attempts: int) -> bytes | None:

switchbot/devices/device.py:206

• [nitpick] Consider adding a docstring to explain the purpose and usage of this helper method.

async def _send_command_locked_with_retry(self, key: str, command: bytes, retry: int, max_attempts: int) -> bytes | None: