Jasper Boot

ArrayUnion should only add elements not already present

1

According to [the documentation](https://firebase.google.com/docs/firestore/manage-data/add-data#update_elements_in_an_array) `ArrayUnion` should only add elements that aren't already present in the array. E.g. this test should succeed: ```py def test_document_update_transformerArrayUnionDuplicates(self): fs = MockFirestore() fs._data = {"foo":...

The current implementation works pretty well, but it has one flaw. It throws a `KeyError` when the document itself does not exist, but a subcollection does. According to the actual...