---
title: "单元测试集"
version: 3.1
locale: zh-hans
source: https://docs.djangoproject.com/zh-hans/3.1/internals/contributing/writing-code/unit-tests/
canonical: https://djangodocs.dev/zh-hans/3.1/internals/contributing/writing-code/unit-tests/
---
# 单元测试集

Django在代码基本库的 `tests` 目录中带有自己的测试套件。 我们的政策是确保所有测试始终通过。

我们感谢对测试套件的所有贡献！

The Django tests all use the testing infrastructure that ships with Django for
testing applications. See [编写并运行测试](/zh-hans/3.1/topics/testing/overview/) for an explanation of
how to write new tests.

## 运行单元测试

### 快速上手

First, [fork Django on GitHub](https://github.com/django/django/fork).

Second, create and activate a virtual environment. If you're not familiar with
how to do that, read our [contributing tutorial](/zh-hans/3.1/intro/contributing/).

Next, clone your fork, install some requirements, and run the tests:

```console
$ git clone https://github.com/YourGitHubName/django.git django-repo
$ cd django-repo/tests
$ python -m pip install -e ..
$ python -m pip install -r requirements/py3.txt
$ ./runtests.py
```

*Windows*

```doscon
...\> git clone https://github.com/YourGitHubName/django.git django-repo
...\> cd django-repo\tests
...\> py -m pip install -e ..
...\> py -m pip install -r requirements\py3.txt
...\> runtests.py
```

Installing the requirements will likely require some operating system packages
that your computer doesn't have installed. You can usually figure out which
package to install by doing a Web search for the last line or so of the error
message. Try adding your operating system to the search query if needed.

If you have trouble installing the requirements, you can skip that step. See
[运行所有测试](#running-unit-tests-dependencies) for details on installing the optional
test dependencies. If you don't have an optional dependency installed, the
tests that require it will be skipped.

Running the tests requires a Django settings module that defines the databases
to use. To help you get started, Django provides and uses a sample settings
module that uses the SQLite database. See [使用另一个 settings 配置模块](#running-unit-tests-settings) to
learn how to use a different settings module to run the tests with a different
database.

Having problems? See [错误调试](#troubleshooting-unit-tests) for some common issues.

### Running tests using `tox`

[Tox](https://tox.readthedocs.io/) is a tool for running tests in different
virtual environments. Django includes a basic `tox.ini` that automates some
checks that our build server performs on pull requests. To run the unit tests
and other checks (such as [import sorting](/zh-hans/3.1/internals/contributing/writing-code/coding-style/#coding-style-imports), the
[documentation spelling checker](/zh-hans/3.1/internals/contributing/writing-documentation/#documentation-spelling-check), and
[code formatting](/zh-hans/3.1/internals/contributing/writing-code/coding-style/#coding-style-python)), install and run the `tox`
command from any place in the Django source tree:

```console
$ python -m pip install tox
$ tox
```

*Windows*

```doscon
...\> py -m pip install tox
...\> tox
```

By default, `tox` runs the test suite with the bundled test settings file for
SQLite, `flake8`, `isort`, and the documentation spelling checker. In
addition to the system dependencies noted elsewhere in this documentation,
the command `python3` must be on your path and linked to the appropriate
version of Python. A list of default environments can be seen as follows:

```console
$ tox -l
py3
flake8
docs
isort>=5.1.0
```

*Windows*

```doscon
...\> tox -l
py3
flake8
docs
isort>=5.1.0
```

#### Testing other Python versions and database backends

In addition to the default environments, `tox` supports running unit tests
for other versions of Python and other database backends. Since Django's test
suite doesn't bundle a settings file for database backends other than SQLite,
however, you must [create and provide your own test settings](#running-unit-tests-settings). For example, to run the tests on Python 3.7
using PostgreSQL:

```console
$ tox -e py37-postgres -- --settings=my_postgres_settings
```

*Windows*

```doscon
...\> tox -e py37-postgres -- --settings=my_postgres_settings
```

This command sets up a Python 3.7 virtual environment, installs Django's
test suite dependencies (including those for PostgreSQL), and calls
`runtests.py` with the supplied arguments (in this case,
`--settings=my_postgres_settings`).

The remainder of this documentation shows commands for running tests without
`tox`, however, any option passed to `runtests.py` can also be passed to
`tox` by prefixing the argument list with `--`, as above.

Tox also respects the [`DJANGO_SETTINGS_MODULE`](/zh-hans/3.1/topics/settings/#envvar-DJANGO_SETTINGS_MODULE) environment variable, if
set. For example, the following is equivalent to the command above:

```console
$ DJANGO_SETTINGS_MODULE=my_postgres_settings tox -e py35-postgres
```

对于 Windows 用户应使用：

```doscon
...\> set DJANGO_SETTINGS_MODULE=my_postgres_settings
...\> tox -e py35-postgres
```

#### 运行 JavaScript 测试集

Django includes a set of [JavaScript unit tests](/zh-hans/3.1/internals/contributing/writing-code/javascript/#javascript-tests) for
functions in certain contrib apps. The JavaScript tests aren't run by default
using `tox` because they require `Node.js` to be installed and aren't
necessary for the majority of patches. To run the JavaScript tests using
`tox`:

```console
$ tox -e javascript
```

*Windows*

```doscon
...\> tox -e javascript
```

This command runs `npm install` to ensure test requirements are up to
date and then runs `npm test`.

### Running tests using `django-docker-box`

[django-docker-box](https://github.com/django/django-docker-box) allows you to run the Django's test suite across all
supported databases and python versions. See the [django-docker-box](https://github.com/django/django-docker-box) project
page for installation and usage instructions.

### 使用另一个 `settings` 配置模块

The included settings module (`tests/test_sqlite.py`) allows you to run the
test suite using SQLite. If you want to run the tests using a different
database, you'll need to define your own settings file. Some tests, such as
those for `contrib.postgres`, are specific to a particular database backend
and will be skipped if run with a different backend.

To run the tests with different settings, ensure that the module is on your
[`PYTHONPATH`](https://docs.python.org/3/using/cmdline.html#envvar-PYTHONPATH) and pass the module with `--settings`.

The [`DATABASES`](/zh-hans/3.1/ref/settings/#std-setting-DATABASES) setting in any test settings module needs to define
two databases:

- A `default` database. This database should use the backend that
  you want to use for primary testing.
- A database with the alias `other`. The `other` database is used to test
  that queries can be directed to different databases. This database should use
  the same backend as the `default`, and it must have a different name.

如果您使用的不是SQLite后端，则需要为每个数据库提供其他详细信息：

- The [`USER`](/zh-hans/3.1/ref/settings/#std-setting-USER) option needs to specify an existing user account
  for the database. That user needs permission to execute `CREATE DATABASE`
  so that the test database can be created.
- [`PASSWORD`](/zh-hans/3.1/ref/settings/#std-setting-PASSWORD) 配置选项需要为指定的配置:setting:USER 提供密码。

Test databases get their names by prepending `test_` to the value of the
[`NAME`](/zh-hans/3.1/ref/settings/#std-setting-NAME) settings for the databases defined in [`DATABASES`](/zh-hans/3.1/ref/settings/#std-setting-DATABASES).
These test databases are deleted when the tests are finished.

You will also need to ensure that your database uses UTF-8 as the default
character set. If your database server doesn't use UTF-8 as a default charset,
you will need to include a value for [`CHARSET`](/zh-hans/3.1/ref/settings/#std-setting-TEST_CHARSET) in the
test settings dictionary for the applicable database.

### 执行一部分测试

Django的整个测试套件需要花一些时间才能运行，并且，例如，如果您刚刚向Django添加了一个想要快速运行而不运行其他所有功能的测试，则运行每个测试可能是多余的。您可以通过在命令行上将测试模块的名称附加到 `runtests.py` 上来运行单元测试的子集。

For example, if you'd like to run tests only for generic relations and
internationalization, type:

```console
$ ./runtests.py --settings=path.to.settings generic_relations i18n
```

*Windows*

```doscon
...\> runtests.py --settings=path.to.settings generic_relations i18n
```

How do you find out the names of individual tests? Look in `tests/` — each
directory name there is the name of a test.

If you want to run only a particular class of tests, you can specify a list of
paths to individual test classes. For example, to run the `TranslationTests`
of the `i18n` module, type:

```console
$ ./runtests.py --settings=path.to.settings i18n.tests.TranslationTests
```

*Windows*

```doscon
...\> runtests.py --settings=path.to.settings i18n.tests.TranslationTests
```

Going beyond that, you can specify an individual test method like this:

```console
$ ./runtests.py --settings=path.to.settings i18n.tests.TranslationTests.test_lazy_objects
```

*Windows*

```doscon
...\> runtests.py --settings=path.to.settings i18n.tests.TranslationTests.test_lazy_objects
```

You can run tests starting at a specified top-level module with `--start-at`
option. For example:

```console
$ ./runtests.py --start-at=wsgi
```

*Windows*

```doscon
...\> runtests.py --start-at=wsgi
```

You can also run tests starting after a specified top-level module with
`--start-after` option. For example:

```console
$ ./runtests.py --start-after=wsgi
```

*Windows*

```doscon
...\> runtests.py --start-after=wsgi
```

Note that the `--reverse` option doesn't impact on `--start-at` or
`--start-after` options. Moreover these options cannot be used with test
labels.

### 运行 Selenium 测试

Some tests require Selenium and a Web browser. To run these tests, you must
install the [selenium](https://pypi.org/project/selenium/) package and run the tests with the
`--selenium=<BROWSERS>` option. For example, if you have Firefox and Google
Chrome installed:

```console
$ ./runtests.py --selenium=firefox,chrome
```

*Windows*

```doscon
...\> runtests.py --selenium=firefox,chrome
```

See the [selenium.webdriver](https://github.com/SeleniumHQ/selenium/tree/master/py/selenium/webdriver) package for the list of available browsers.

Specifying `--selenium` automatically sets `--tags=selenium` to run only
the tests that require selenium.

Some browsers (e.g. Chrome or Firefox) support headless testing, which can be
faster and more stable. Add the `--headless` option to enable this mode.

### 运行所有测试

如果要运行全套测试，则需要安装许多依赖项：

- [argon2-cffi](https://pypi.org/project/argon2_cffi/) 16.1.0+
- [asgiref](https://pypi.org/project/asgiref/) 3.2.10+ (required)
- [bcrypt](https://pypi.org/project/bcrypt/)
- [docutils](https://pypi.org/project/docutils/)
- [geoip2](https://pypi.org/project/geoip2/)
- [jinja2](https://pypi.org/project/jinja2/) 2.7+
- [numpy](https://pypi.org/project/numpy/)
- [Pillow](https://pypi.org/project/Pillow/) 6.2.0+
- [PyYAML](https://pyyaml.org/wiki/PyYAML)
- [pytz](https://pypi.org/project/pytz/) (required)
- [pywatchman](https://pypi.org/project/pywatchman/)
- [setuptools](https://pypi.org/project/setuptools/)
- [memcached](https://memcached.org/), 加上:ref:supported Python binding \<memcached\>
- [gettext](https://www.gnu.org/software/gettext/manual/gettext.html) ([Windows 上的 gettext](/zh-hans/3.1/topics/i18n/translation/#gettext-on-windows))
- [selenium](https://pypi.org/project/selenium/)
- [sqlparse](https://pypi.org/project/sqlparse/) 0.2.2+ (required)
- [tblib](https://pypi.org/project/tblib/) 1.5.0+

You can find these dependencies in [pip requirements files](https://pip.pypa.io/en/latest/user_guide/#requirements-files) inside the
`tests/requirements` directory of the Django source tree and install them
like so:

```console
$ python -m pip install -r tests/requirements/py3.txt
```

*Windows*

```doscon
...\> py -m pip install -r tests\requirements\py3.txt
```

如果你在安装过程中发生了错误，可能是你的系统缺少一个或多个Python依赖包。请参考安装失败的包的文档或者在网上搜索错误的提示信息。

You can also install the database adapter(s) of your choice using
`oracle.txt`, `mysql.txt`, or `postgres.txt`.

如果要测试memcached缓存后端，则还需要定义一个指向您配置的memcached实例的 [`CACHES`](/zh-hans/3.1/ref/settings/#std-setting-CACHES) 配置。

To run the GeoDjango tests, you will need to [setup a spatial database
and install the Geospatial libraries](/zh-hans/3.1/ref/contrib/gis/install/).

这些依赖项中的每一个都是可选的。 如果您缺少其中的任何一个，则将跳过关联的测试。

To run some of the autoreload tests, you'll need to install the [Watchman](https://facebook.github.io/watchman/)
service.

### 代码覆盖率

鼓励贡献者对测试套件进行覆盖率测试，以确定需要额外测试的区域。在:ref:testing code coverage 1. 中介绍了coverage代码覆盖度工具的安装和使用。

Coverage should be run in a single process to obtain accurate statistics. To
run coverage on the Django test suite using the standard test settings:

```console
$ coverage run ./runtests.py --settings=test_sqlite --parallel=1
```

*Windows*

```doscon
...\> coverage run runtests.py --settings=test_sqlite --parallel=1
```

After running coverage, generate the html report by running:

```console
$ coverage html
```

*Windows*

```doscon
...\> coverage html
```

运行Django测试的覆盖率时，随附的 `.coveragerc` 配置文件将 `coverage_html` 定义为报告的输出目录，并且还排除了与结果无关的几个目录（Django中包含的测试代码或外部代码）。

## Contrib 应用程序

Tests for contrib apps can be found in the `tests/` directory, typically
under `<app_name>_tests`. For example, tests for `contrib.auth` are located
in `tests/auth_tests`.

## 错误调试

### Test suite hangs or shows failures on `master` branch

Ensure you have the latest point release of a [supported Python version](/zh-hans/3.1/faq/install/#faq-python-version-support), since there are often bugs in earlier versions
that may cause the test suite to fail or hang.

On **macOS** (High Sierra and newer versions), you might see this message
logged, after which the tests hang:

```
objc[42074]: +[__NSPlaceholderDate initialize] may have been in progress in
another thread when fork() was called.
```

To avoid this set a `OBJC_DISABLE_INITIALIZE_FORK_SAFETY` environment
variable, for example:

```
$ OBJC_DISABLE_INITIALIZE_FORK_SAFETY=YES ./runtests.py
```

Or add `export OBJC_DISABLE_INITIALIZE_FORK_SAFETY=YES` to your shell's
startup file (e.g. `~/.profile`).

### Many test failures with `UnicodeEncodeError`

If the `locales` package is not installed, some tests will fail with a
`UnicodeEncodeError`.

You can resolve this on Debian-based systems, for example, by running:

```console
$ apt-get install locales
$ dpkg-reconfigure locales
```

You can resolve this for macOS systems by configuring your shell's locale:

```console
$ export LANG="en_US.UTF-8"
$ export LC_ALL="en_US.UTF-8"
```

Run the `locale` command to confirm the change. Optionally, add those export
commands to your shell's startup file (e.g. `~/.bashrc` for Bash) to avoid
having to retype them.

### Tests that only fail in combination

In case a test passes when run in isolation but fails within the whole suite,
we have some tools to help analyze the problem.

The `--bisect` option of `runtests.py` will run the failing test while
halving the test set it is run together with on each iteration, often making
it possible to identify a small number of tests that may be related to the
failure.

For example, suppose that the failing test that works on its own is
`ModelTest.test_eq`, then using:

```console
$ ./runtests.py --bisect basic.tests.ModelTest.test_eq
```

*Windows*

```doscon
...\> runtests.py --bisect basic.tests.ModelTest.test_eq
```

will try to determine a test that interferes with the given one. First, the
test is run with the first half of the test suite. If a failure occurs, the
first half of the test suite is split in two groups and each group is then run
with the specified test. If there is no failure with the first half of the test
suite, the second half of the test suite is run with the specified test and
split appropriately as described earlier. The process repeats until the set of
failing tests is minimized.

The `--pair` option runs the given test alongside every other test from the
suite, letting you check if another test has side-effects that cause the
failure. So:

```console
$ ./runtests.py --pair basic.tests.ModelTest.test_eq
```

*Windows*

```doscon
...\> runtests.py --pair basic.tests.ModelTest.test_eq
```

will pair `test_eq` with every test label.

With both `--bisect` and `--pair`, if you already suspect which cases
might be responsible for the failure, you may limit tests to be cross-analyzed
by [specifying further test labels](#runtests-specifying-labels) after
the first one:

```console
$ ./runtests.py --pair basic.tests.ModelTest.test_eq queries transactions
```

*Windows*

```doscon
...\> runtests.py --pair basic.tests.ModelTest.test_eq queries transactions
```

You can also try running any set of tests in reverse using the `--reverse`
option in order to verify that executing tests in a different order does not
cause any trouble:

```console
$ ./runtests.py basic --reverse
```

*Windows*

```doscon
...\> runtests.py basic --reverse
```

### Seeing the SQL queries run during a test

If you wish to examine the SQL being run in failing tests, you can turn on
[SQL logging](/zh-hans/3.1/topics/logging/#django-db-logger) using the `--debug-sql` option. If you
combine this with `--verbosity=2`, all SQL queries will be output:

```console
$ ./runtests.py basic --debug-sql
```

*Windows*

```doscon
...\> runtests.py basic --debug-sql
```

### Seeing the full traceback of a test failure

By default tests are run in parallel with one process per core. When the tests
are run in parallel, however, you'll only see a truncated traceback for any
test failures. You can adjust this behavior with the `--parallel` option:

```console
$ ./runtests.py basic --parallel=1
```

*Windows*

```doscon
...\> runtests.py basic --parallel=1
```

You can also use the [`DJANGO_TEST_PROCESSES`](/zh-hans/3.1/ref/django-admin/#envvar-DJANGO_TEST_PROCESSES) environment variable for
this purpose.

## Tips for writing tests

### Isolating model registration

To avoid polluting the global [`apps`](/zh-hans/3.1/ref/applications/#django.apps.apps) registry and prevent
unnecessary table creation, models defined in a test method should be bound to
a temporary `Apps` instance:

```python
from django.apps.registry import Apps
from django.db import models
from django.test import SimpleTestCase

class TestModelDefinition(SimpleTestCase):
    def test_model_definition(self):
        test_apps = Apps(['app_label'])

        class TestModel(models.Model):
            class Meta:
                apps = test_apps
        ...
```

#### `django.test.utils.isolate_apps(*app_labels, attr_name=None, kwarg_name=None)`

Since this pattern involves a lot of boilerplate, Django provides the
[`isolate_apps()`](#django.test.utils.isolate_apps) decorator. It's used like this:

```python
from django.db import models
from django.test import SimpleTestCase
from django.test.utils import isolate_apps

class TestModelDefinition(SimpleTestCase):
    @isolate_apps('app_label')
    def test_model_definition(self):
        class TestModel(models.Model):
            pass
        ...
```

> **Setting app_label**
>
> Models defined in a test method with no explicit
> [`app_label`](/zh-hans/3.1/ref/models/options/#django.db.models.Options.app_label) are automatically assigned the
> label of the app in which their test class is located.
>
> In order to make sure the models defined within the context of
> [`isolate_apps()`](#django.test.utils.isolate_apps) instances are correctly
> installed, you should pass the set of targeted `app_label` as arguments:
>
> *tests/app\_label/tests.py*
>
> ```python
> from django.db import models
> from django.test import SimpleTestCase
> from django.test.utils import isolate_apps
>
> class TestModelDefinition(SimpleTestCase):
>     @isolate_apps('app_label', 'other_app_label')
>     def test_model_definition(self):
>         # This model automatically receives app_label='app_label'
>         class TestModel(models.Model):
>             pass
>
>         class OtherAppModel(models.Model):
>             class Meta:
>                 app_label = 'other_app_label'
>         ...
> ```

The decorator can also be applied to classes:

```python
from django.db import models
from django.test import SimpleTestCase
from django.test.utils import isolate_apps

@isolate_apps('app_label')
class TestModelDefinition(SimpleTestCase):
    def test_model_definition(self):
        class TestModel(models.Model):
            pass
        ...
```

The temporary `Apps` instance used to isolate model registration can be
retrieved as an attribute when used as a class decorator by using the
`attr_name` parameter:

```python
from django.db import models
from django.test import SimpleTestCase
from django.test.utils import isolate_apps

@isolate_apps('app_label', attr_name='apps')
class TestModelDefinition(SimpleTestCase):
    def test_model_definition(self):
        class TestModel(models.Model):
            pass
        self.assertIs(self.apps.get_model('app_label', 'TestModel'), TestModel)
```

Or as an argument on the test method when used as a method decorator by using
the `kwarg_name` parameter:

```python
from django.db import models
from django.test import SimpleTestCase
from django.test.utils import isolate_apps

class TestModelDefinition(SimpleTestCase):
    @isolate_apps('app_label', kwarg_name='apps')
    def test_model_definition(self, apps):
        class TestModel(models.Model):
            pass
        self.assertIs(apps.get_model('app_label', 'TestModel'), TestModel)
```