Question

直接症状：

$ pytest …/apps/users/test/test_graph_permissions_command.py
============================= test session starts ==============================
platform linux -- Python 3.6.8, pytest-4.6.2, py-1.8.0, pluggy-0.12.0
Django settings: dms.settings (from ini file)
rootdir: /src/app, inifile: pytest.ini
plugins: forked-1.0.2, celery-4.3.0, django-3.5.0, cov-2.7.1, xdist-1.28.0
collected 1 item                                                               

…/apps/users/test/test_graph_permissions_command.py E

==================================== ERRORS ====================================
_ ERROR at setup of TestGraphPermissionsCommand.test_should_resolve_a_permission_hierarchy _
.venv/lib/python3.6/site-packages/pytest_django/plugin.py:519: in _django_setup_unittest
    request.getfixturevalue("django_db_setup")
.venv/lib/python3.6/site-packages/pytest_django/fixtures.py:108: in django_db_setup
    **setup_databases_args
.venv/lib/python3.6/site-packages/django/test/utils.py:174: in setup_databases
    serialize=connection.settings_dict.get('TEST', {}).get('SERIALIZE', True),
.venv/lib/python3.6/site-packages/django/db/backends/base/creation.py:80: in create_test_db
    self.connection._test_serialized_contents = self.serialize_db_to_string()
.venv/lib/python3.6/site-packages/django/db/backends/base/creation.py:123: in serialize_db_to_string
    serializers.serialize("json", get_objects(), indent=None, stream=out)
.venv/lib/python3.6/site-packages/django/core/serializers/__init__.py:128: in serialize
    s.serialize(queryset, **options)
.venv/lib/python3.6/site-packages/django/core/serializers/base.py:90: in serialize
    for count, obj in enumerate(queryset, start=1):
.venv/lib/python3.6/site-packages/django/db/backends/base/creation.py:120: in get_objects
    yield from queryset.iterator()
.venv/lib/python3.6/site-packages/django/db/models/query.py:341: in _iterator
    yield from self._iterable_class(self, chunked_fetch=use_chunked_fetch, chunk_size=chunk_size)
.venv/lib/python3.6/site-packages/polymorphic/query.py:56: in _polymorphic_iterator
    o = next(base_iter)
.venv/lib/python3.6/site-packages/django/db/models/query.py:55: in __iter__
    results = compiler.execute_sql(chunked_fetch=self.chunked_fetch, chunk_size=self.chunk_size)
.venv/lib/python3.6/site-packages/django/db/models/sql/compiler.py:1087: in execute_sql
    sql, params = self.as_sql()
.venv/lib/python3.6/site-packages/django/db/models/sql/compiler.py:474: in as_sql
    extra_select, order_by, group_by = self.pre_sql_setup()
.venv/lib/python3.6/site-packages/django/db/models/sql/compiler.py:54: in pre_sql_setup
    self.setup_query()
.venv/lib/python3.6/site-packages/django/db/models/sql/compiler.py:45: in setup_query
    self.select, self.klass_info, self.annotation_col_map = self.get_select()
.venv/lib/python3.6/site-packages/django/db/models/sql/compiler.py:219: in get_select
    cols = self.get_default_columns()
.venv/lib/python3.6/site-packages/django/db/models/sql/compiler.py:666: in get_default_columns
    column = field.get_col(alias)
.venv/lib/python3.6/site-packages/django/db/models/fields/related.py:981: in get_col
    output_field = self.target_field
.venv/lib/python3.6/site-packages/django/db/models/fields/related.py:878: in target_field
    return self.foreign_related_fields[0]
.venv/lib/python3.6/site-packages/django/db/models/fields/related.py:632: in foreign_related_fields
    return tuple(rhs_field for lhs_field, rhs_field in self.related_fields if rhs_field)
.venv/lib/python3.6/site-packages/django/db/models/fields/related.py:619: in related_fields
    self._related_fields = self.resolve_related_fields()
.venv/lib/python3.6/site-packages/django/db/models/fields/related.py:604: in resolve_related_fields
    raise ValueError('Related model %r cannot be resolved' % self.remote_field.model)
E   ValueError: Related model 'appname.ModelName' cannot be resolved
=========================== 1 error in 5.54 seconds ============================

测试文件：

$ cat …/apps/users/test/test_graph_permissions_command.py
from django.test import TestCase


class TestGraphPermissionsCommand(TestCase):
    def test_should_resolve_a_permission_hierarchy(self) -> None:
        pass

情况：

使用另一个文件测试test_graph_permissions_command.py可以正常工作-其他任何文件似乎都可以正常工作，并且无论test_graph_permissions_command.py位于第一个还是最后一个都可以。
从TestCase导入unittest可以，但是在实际测试中我需要django.test.TestCase中的一些东西。
测试任何 other 个单个文件也可以。
我重建了每天晚上运行的虚拟机，并且一位同事能够重现此问题，因此它不是我的设置唯一的。
./manage.py makemigrations报告“未检测到更改”。
许多其他测试类都从同一个TestCase类继承而来。
错误消息中的应用程序和模型已经过很好的测试。这两个模型分别具有ForeignKey至"appname.ModelName"的同上。代码覆盖率为98％。

这是怎么回事？看来这可能是由于测试数据库构建器未能按正确的顺序执行操作引起的。

运行单个测试文件时，Django测试设置失败

0 个答案: