Currently the tests are organized like:

test/
   unit/
   integration/

But it is not clear what tests should be where. Some unit tests require that the firestore emulator be running while others do not.

Maybe it would make sense to consolidate all of the tests into a single directory and use tags to control whether they get run or not.

googleapis/google-cloud-dart groups related tests in the same file and uses tags to control what tests are actually.

For example:

# Run all of the untagged tests
dart test
# Run tests that require a real GCP project
GOOGLE_CLOUD_PROJECT=$(gcloud config get-value project) dart test . -P google-cloud  
# Run tests the require the firebase emulator
FIRESTORE_EMULATOR_HOST=127.0.0.1:8080 dart test -P firebase-emulator .

Some tests apply multiple tags to the same test. For example, these tests work with either a real GCP project configured or with the firestore emulator.