true if the snapshot contains the result of local writes (e.g. write() or update() calls) that have not yet been committed to the backend. If your listener has opted into metadata updates (via 'DocumentListenOptions' or 'QueryListenOptions') you will receive another snapshot with 'hasPendingWrites' equal to false once the writes have been committed to the backend.

true if the snapshot was created from cached data rather than guaranteed up-to-date server data. If your listener has opted into metadata updates (via 'DocumentListenOptions' or 'QueryListenOptions') you will receive another snapshot with 'isFomCache' equal to false once the client has received up-to-date data from the backend.