Reproducer for google-cloud-python #7756

repro_gcp_7756.py

import sys

from google.cloud.firestore_v1 import Client


def cleanup(coll):
    for doc in coll.list_documents():
        print("Removing: {}".format(doc.path))
        doc.delete()

def initialize(coll):
    for index in range(100):
        doc = coll.document('test_{:09d}'.format(index))
        data = {
            'count': 10 * index,
            'wordcount': {
                'page1': index * 10 + 100,
            },
        }
        print("Setting: {}".format(doc.path))
        doc.set(data)

def main(client):
    coll = client.collection('gcp-7756')

    if '--reinit' in sys.argv:
        cleanup(coll)
        initialize(coll)

    for snapshot in coll.order_by('wordcount.page1').limit(3).stream():
        last_value = snapshot.get('wordcount.page1')

    good_cursor = {
        'wordcount': {
            'page1': last_value
        }
    }

    found = list(coll.order_by('wordcount.page1').start_after(good_cursor).limit(3).stream())

    bad_cursor = {'wordcount.page1': last_value}

    # Will fail:
    try:
        list(coll.order_by('wordcount.page1').start_after(bad_cursor).limit(3).stream())
    except ValueError as exc:
        print(exc)
    else:
        assert False, "Shouldn't succeed"


if __name__ == '__main__':
    client = Client()
    main(client)