Search: Escape sequences

[dranikpg]

Test escaping and direct qutoes to be on the safe side

[CodeToFreedom]

@dranikpg
Unfortunately just escaping the sequences works only in dragonflydb but not in redis.
As this syntax difference causes major query problems/crashes in our efforts to migrate to this otherwhise really awesome dragonfly library, I added the solution here as well hoping it gets seen by one of the contributors: #3258 (comment)

The problem:

This works in redis (but fails in dragonflydb):
"FT.SEARCH" ":Language:index" "(@code:{ZH\\-CN})" "LIMIT" "0" "1"

This works in dragonflydb (but fails in redis):
"FT.SEARCH" ":Language:index" "(@code:{'ZH-CN'})" "LIMIT" "0" "1"

Here is the fix:

To fix that and make dragonflydb behave like the redis tokenizer please escape the following regex matches with two backslashes.
DEFAULT_ESCAPED_CHARS = r"[,.<>{}\[\]\\\"\':;!@#$%^&*()\-+=~\/ ]"

The matching regex groups need to be ESCAPED like that:
f"\\{value}"

References:
Here is a completely working token escaper from a redis client library:
Source: https://github.com/redis/redis-om-python/blob/main/aredis_om/model/token_escaper.py

Many thanks for your efforts.

[CodeToFreedom]

@dranikpg I added more detailed test script and syntax examples: #3258 (comment)