[matthi4s]

Since #34 (v5.0.0), RedisQueryException::checkConnection() throws unless Redis::getLastError() returns false. But phpredis returns null when there is no error (checked 5.3.7, 6.0.0 and 6.3.0), and false only when there is no connection at all. So every save(), get() and delete() of a model with a cache time throws an empty RedisQueryException: Redis Query Error: , which makes the Redis cache unusable.

Changes

• checkConnection() only throws if getLastError() returns a string, and clears the error before throwing. phpredis keeps the last error until clearLastError() is called, so it would otherwise be reported again for every later query.
• save(), get() and delete() clear the last error before running their command, so an error left by another command on the same connection (e.g. when the connection is shared with other code) isn't reported as a model error.
• Add RedisQueryExceptionTest (uses a \Redis stub, requires ext-redis) and enable the redis extension in the test workflow so it runs in CI.

Testing

• Full test suite passes with phpredis 6.3.0 (88 tests); the new test fails on the old code.
• Checked against a real Redis 7.4 together with MySQL and OpenSearch: cached save/get/delete work again, a real error from the driver's own command (WRONGTYPE) is still thrown, and the next query works normally afterwards.

Models without a cache time are not affected, since the driver returns before connecting.