$in operator fails on array fields

[Dobatymo]

According to https://docs.mongodb.com/manual/reference/operator/query/in/#mongodb-query-op.-in

If the field holds an array, then the $in operator selects the documents whose field holds an array that contains at least one element that matches a value in the specified array (for example, <value1>, <value2>, and so on).

mongita raises an error in this case:

Traceback (most recent call last):
  File "test.py", line 57, in test_mongita
    result = list(col.find({"names: {"$in": ["asd", "qwe"]}}))
  File "Python38\lib\site-packages\mongita\cursor.py", line 56, in __iter__
    for el in self._gen():
  File "Python38\lib\site-packages\mongita\collection.py", line 870, in __find
    for doc_id in self.__find_ids(filter, sort, limit, metadata=metadata):
  File "Python38\lib\site-packages\mongita\collection.py", line 845, in __find_ids
    if doc and _doc_matches_slow_filters(doc, slow_filters):
  File "Python38\lib\site-packages\mongita\collection.py", line 193, in _doc_matches_slow_filters
    if _doc_matches_agg(doc_v, query_ops):
  File "Python38\lib\site-packages\mongita\collection.py", line 143, in _doc_matches_agg
    if doc_v not in query_val:
TypeError: unhashable type: 'list'

[scottrogowski]

Just acknowledging that I have seen this. I looked over the code and did some quick tests and it looks like I missed implementing the second part of $in functionality that you mention. That certainly needs to get fixed.

What I could not do was reproduce your TypeError which is a little more concerning to me. Do you have any example documents that will cause that to trigger? Are you using memory or disk?

[scottrogowski]

Candidate patch to address $in/$nin behavior - https://github.com/scottrogowski/mongita/pull/21/files

Would still be curious if you have a way to reproduce the TypeError

[Dobatymo]

@scottrogowski Sorry, my $in parameter was a set. I edited the traceback incorrectly. It should look like this.

result = list(col.find({"names: {"$in": {"asd", "qwe"}}}))

[scottrogowski]

Ah, you had me worried there. PyMongo throws an error when you use sets as well. The difference is that it's a bson.errors.InvalidDocument rather than a TypeError. So while I think I'll try to reproduce that exact error, I'm not as worried.

Regardless, you helped me find something I had overlooked with the $in/$nin operators... so thank you.

[Dobatymo]

Yes sorry I didn't test the code with pymongo. I noticed that sets did work with the standard (non-array field) $in operator so I just extended the code to the array field version and saw the error.

[scottrogowski]

Addressed the $in/$nin with V1.1. I'll set aside document validation for sets for the moment in favor of a larger release later.