Incorrect type hints in collection()

[mbrancato]

Environment details

• OS type and version: MacOS
• Python version: Python 3.7.7
• google-cloud-firestore version: 2.0.2

At some point recently the type hints for for Client().collection() methods were changed, and they do not reflect examples or the docs. I'm getting type hint warnings.

python-firestore/google/cloud/firestore_v1/client.py

Line 120 in 30bb3fb

def collection(self, *collection_path: Tuple[str]) -> CollectionReference:

Should the type hint be changed to simply str ? All the comments and docs show these:

client.collection('top')
client.collection('mydocs/doc/subcol')
client.collection('mydocs', 'doc', 'subcol')

None of these are Tuple[str]. The argument *collection_path will produce a tuple when called, but it is called with strings.

[tseaver]

Per the implementation, the collection_path argument can be either a single, slash-delimited path string, or a Tuple[str]. See the _path_helper function, which also has an incorrect typespec for its argument.

[tseaver]

A correction: the leading asterisk (*collection_path) means that the value received by the function will always be a tuple, and we require that the elements of the tuple be strings. The caller may pass a single string, e.g. client.collection("mydocs/doc/subcol"), which will be split on the slashes, exactly as if the caller had passed client.collection("mydocs", "doc", "subcol"). That example is from the docstring of Client.collection.

[tseaver]

OK, looking at PEP 484, it appears that *args should be typed as the type of one element.