unit-testing - GAE 测试以验证 ndb 实体是否**未**放入数据存储区

Question

非常简单，我想运行一些代码并验证没有实体类型MyEntity(ndb.Model)被放入数据存储。

我试过 MyEntity.query().fetch(keys_only=True)，但这似乎不是强一致的(即它没有显示我的实体)刚刚添加)，所以返回一个空列表不是真正的确认。 (我应该补充一点，我正在使用 testbed.init_datastore_v3_stub 并且我已经尝试过 datastore_stub_util.PseudoRandomHRConsistencyPolicy(probability=1) 和 MasterSlaveConsistencyPolicy() 没有成功。)

我认为有一种方法可以对所有类型的键进行高度一致的“获取”，但现在我找不到任何文档来支持它。

我知道如果我有一个 key ，我可以执行强一致性获取，但是这将如何转化为验证未添加实体，因此没有 key 可获取？

Answer 1

好吧，我终于在disabling the ndb cache via global context 之前让它工作了| (由 How to Clear/Invalidate NDB Cache in Tests 提示)除了 normal unit testing testbeds .

还帮助了:

• > What's the equivalent of Entity.all(keys_only=True).fetch(20) in NDB?
• > How to fetch the latest data in GAE Python NDB

辅助混合:

class NdbTestbedNoCachingStronglyConsistentMixin(unittest.TestCase):
    def setUp(self):
        self.testbed = testbed.Testbed()
        self.testbed.activate()
        policy = None
        # policy = datastore_stub_util.MasterSlaveConsistencyPolicy()
        # policy = datastore_stub_util.PseudoRandomHRConsistencyPolicy(probability=1.0)
        self.testbed.init_datastore_v3_stub(consistency_policy=policy)
        # self.testbed.init_memcache_stub()

        # It's not enough (or necessary) to use stubs for datastore and memcache -
        # we also need to change ndb policy to ensure that datastore queries
        # are strongly-consistent
        cxt = ndb.get_context()

        def disallow(*args, **kwargs):
            return False

        cxt.set_cache_policy(disallow)
        cxt.set_memcache_policy(disallow)
        super(NdbTestbedNoCachingStronglyConsistentMixin, self).setUp()

    def tearDown(self):
        super(NdbTestbedNoCachingStronglyConsistentMixin, self).tearDown()
        self.testbed.deactivate()

像这样使用(省略了一些不相关的代码):

def _get_entity_keys():
    return MyNdbEntity.query().fetch(keys_only=True)


class TestMyEntity(NdbTestbedNoCachingStronglyConsistentMixin):

    def tearDown(self):
        super(TestMyEntity, self).tearDown()

        # Verify our assumptions that no entities persist between tests
        assert MyNdbEntity.get_by_identifier(self.account, TEST_IDENTIFIER) is None
        assert not _get_entity_keys()

    def test_get_uri_should_retrieve_existing_entity(self):
        provider.get_uri(TEST_IDENTIFIER)  # creates entity
        all_assets_keys = _get_entity_keys()
        created_asset = MyNdbEntity.get_by_identifier(self.account, TEST_IDENTIFIER)

        self.assertIn(created_asset.key, all_assets_keys)

        provider.get_uri(TEST_IDENTIFIER)
        all_assets_keys_after_get = _get_entity_keys()

        self.assertSequenceEqual(all_assets_keys_after_get, all_assets_keys)


    def test_get_uri_should_create_entity_and_prefix_identifier_with_security_id(self):
        expected_identifier = TEST_SECURITY_ID + '-' + TEST_IDENTIFIER
        expected_uri = VIEWER_IMAGE_BASE_URI % expected_identifier

        uri = provider.get_uri(TEST_IDENTIFIER)
        image = _get_entity_keys()[0].get()

        self.assertEqual(image.identifier, expected_identifier)
        self.assertEqual(uri, expected_uri)