在Django中进行硒测试后数据库仍在使用中

Question

我有一个Django项目，我将在其中开始编写Selenium测试。第一个看起来像这样：

from django.contrib.staticfiles.testing import StaticLiveServerTestCase
from selenium import webdriver
from selenium.webdriver.common.keys import Keys

from core.models import User
from example import settings

BACH_EMAIL = "johann.sebastian.bach@classics.com"
PASSWORD = "password"


class TestImportCRMData(StaticLiveServerTestCase):
    @classmethod
    def setUpClass(cls):
        super().setUpClass()
        cls.webdriver = webdriver.Chrome()
        cls.webdriver.implicitly_wait(10)

    @classmethod
    def tearDownClass(cls):
        cls.webdriver.close()
        cls.webdriver.quit()
        super().tearDownClass()

    def setUp(self):
        self.admin = User.objects.create_superuser(email=BACH_EMAIL, password=PASSWORD)

    def test_admin_tool(self):
        self.webdriver.get(f"http://{settings.ADMIN_HOST}:{self.server_thread.port}/admin")

        self.webdriver.find_element_by_id("id_username").send_keys(BACH_EMAIL)
        self.webdriver.find_element_by_id("id_password").send_keys(PASSWORD)
        self.webdriver.find_element_by_id("id_password").send_keys(Keys.RETURN)
        self.webdriver.find_element_by_link_text("Users").click()

当我运行它时，测试通过但仍然以以下错误结束：

Traceback (most recent call last):
  File "C:\Users\pupeno\Documents\Eligible\code\example\venv\lib\site-packages\django\db\backends\utils.py", line 83, in _execute
    return self.cursor.execute(sql)
psycopg2.OperationalError: database "test_example" is being accessed by other users
DETAIL:  There is 1 other session using the database.


The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "C:\Program Files\JetBrains\PyCharm 2018.2.4\helpers\pycharm\django_test_manage.py", line 168, in <module>
    utility.execute()
  File "C:\Program Files\JetBrains\PyCharm 2018.2.4\helpers\pycharm\django_test_manage.py", line 142, in execute
    _create_command().run_from_argv(self.argv)
  File "C:\Users\pupeno\Documents\Eligible\code\example\venv\lib\site-packages\django\core\management\commands\test.py", line 26, in run_from_argv
    super().run_from_argv(argv)
  File "C:\Users\pupeno\Documents\Eligible\code\example\venv\lib\site-packages\django\core\management\base.py", line 316, in run_from_argv
    self.execute(*args, **cmd_options)
  File "C:\Users\pupeno\Documents\Eligible\code\example\venv\lib\site-packages\django\core\management\base.py", line 353, in execute
    output = self.handle(*args, **options)
  File "C:\Program Files\JetBrains\PyCharm 2018.2.4\helpers\pycharm\django_test_manage.py", line 104, in handle
    failures = TestRunner(test_labels, **options)
  File "C:\Program Files\JetBrains\PyCharm 2018.2.4\helpers\pycharm\django_test_runner.py", line 255, in run_tests
    extra_tests=extra_tests, **options)
  File "C:\Program Files\JetBrains\PyCharm 2018.2.4\helpers\pycharm\django_test_runner.py", line 156, in run_tests
    return super(DjangoTeamcityTestRunner, self).run_tests(test_labels, extra_tests, **kwargs)
  File "C:\Users\pupeno\Documents\Eligible\code\example\venv\lib\site-packages\django\test\runner.py", line 607, in run_tests
    self.teardown_databases(old_config)
  File "C:\Users\pupeno\Documents\Eligible\code\example\venv\lib\site-packages\django\test\runner.py", line 580, in teardown_databases
    keepdb=self.keepdb,
  File "C:\Users\pupeno\Documents\Eligible\code\example\venv\lib\site-packages\django\test\utils.py", line 297, in teardown_databases
    connection.creation.destroy_test_db(old_name, verbosity, keepdb)
  File "C:\Users\pupeno\Documents\Eligible\code\example\venv\lib\site-packages\django\db\backends\base\creation.py", line 257, in destroy_test_db
    self._destroy_test_db(test_database_name, verbosity)
  File "C:\Users\pupeno\Documents\Eligible\code\example\venv\lib\site-packages\django\db\backends\base\creation.py", line 274, in _destroy_test_db
    % self.connection.ops.quote_name(test_database_name))
  File "C:\Users\pupeno\Documents\Eligible\code\example\venv\lib\site-packages\django\db\backends\utils.py", line 68, in execute
    return self._execute_with_wrappers(sql, params, many=False, executor=self._execute)
  File "C:\Users\pupeno\Documents\Eligible\code\example\venv\lib\site-packages\django\db\backends\utils.py", line 77, in _execute_with_wrappers
    return executor(sql, params, many, context)
  File "C:\Users\pupeno\Documents\Eligible\code\example\venv\lib\site-packages\django\db\backends\utils.py", line 85, in _execute
    return self.cursor.execute(sql, params)
  File "C:\Users\pupeno\Documents\Eligible\code\example\venv\lib\site-packages\django\db\utils.py", line 89, in __exit__
    raise dj_exc_value.with_traceback(traceback) from exc_value
  File "C:\Users\pupeno\Documents\Eligible\code\example\venv\lib\site-packages\django\db\backends\utils.py", line 83, in _execute
    return self.cursor.execute(sql)
django.db.utils.OperationalError: database "test_example" is being accessed by other users
DETAIL:  There is 1 other session using the database.

当然，问题在于，下一次运行测试时，数据库仍然存在，因此，在不确认删除数据库的情况下不会运行测试。

如果我在最后一行注释掉：

self.webdriver.find_element_by_link_text("Users").click()

那么我不会得到这个错误。我猜只是因为没有建立数据库连接。有时是另外1个会话，有时最多是4个会话。在4个会话的情况之一中，这些是正在运行的会话：

select * from pg_stat_activity where datname = 'test_example';

100123  test_example    29892   16393   pupeno  ""  ::1     61967   2018-11-15 17:28:19.552431      2018-11-15 17:28:19.562398  2018-11-15 17:28:19.564623          idle            SELECT "core_user"."id", "core_user"."password", "core_user"."last_login", "core_user"."is_superuser", "core_user"."email", "core_user"."is_staff", "core_user"."is_active", "core_user"."date_joined" FROM "core_user" WHERE "core_user"."id" = 1
100123  test_example    33028   16393   pupeno  ""  ::1     61930   2018-11-15 17:28:18.792466      2018-11-15 17:28:18.843383  2018-11-15 17:28:18.851828          idle            SELECT "django_admin_log"."id", "django_admin_log"."action_time", "django_admin_log"."user_id", "django_admin_log"."content_type_id", "django_admin_log"."object_id", "django_admin_log"."object_repr", "django_admin_log"."action_flag", "django_admin_log"."change_message", "core_user"."id", "core_user"."password", "core_user"."last_login", "core_user"."is_superuser", "core_user"."email", "core_user"."is_staff", "core_user"."is_active", "core_user"."date_joined", "django_content_type"."id", "django_content_type"."app_label", "django_content_type"."model" FROM "django_admin_log" INNER JOIN "core_user" ON ("django_admin_log"."user_id" = "core_user"."id") LEFT OUTER JOIN "django_content_type" ON ("django_admin_log"."content_type_id" = "django_content_type"."id") WHERE "django_admin_log"."user_id" = 1 ORDER BY "django_admin_log"."action_time" DESC  LIMIT 10
100123  test_example    14128   16393   pupeno  ""  ::1     61988   2018-11-15 17:28:19.767225      2018-11-15 17:28:19.776150  2018-11-15 17:28:19.776479          idle            SELECT "core_firm"."id", "core_firm"."name", "core_firm"."host_name" FROM "core_firm" WHERE "core_firm"."id" = 1
100123  test_example    9604    16393   pupeno  ""  ::1     61960   2018-11-15 17:28:19.469197      2018-11-15 17:28:19.478775  2018-11-15 17:28:19.478788          idle            COMMIT

我一直在尝试找到此问题的最小可复制示例，但到目前为止，我还没有成功。

有什么想法可能导致此问题，或者如何找到更多有关此问题的原因？

Answer 1

检查活动连接以了解导致问题的原因 select * from pg_stat_activity;

您可以禁用扩展：

    @classmethod
    def setUpClass(cls):
        super().setUpClass()
        options = webdriver.chrome.options.Options()
        options.add_argument("--disable-extensions") 
        cls.webdriver = webdriver.Chrome(chrome_options=options)
        cls.webdriver.implicitly_wait(10)

然后在拆解中：

    @classmethod
    def tearDownClass(cls):
        cls.webdriver.stop_client()
        cls.webdriver.quit()
        connections.close_all()
        super().tearDownClass()