Menulis dan menjalankan percobaan¶

Lihat juga

testing tutorial, the testing tools reference, dan advanced testing topics.

Dokumen ini dipisah menjadi dua bagian utama. Pertama, kami menjelaskan bagaimana menulis percobaan dengan Django. Kemudian, kami menjelaskan bagaimana menjalankan mereka.

Menulis percobaan¶

Django's unit tests use a Python standard library module: unittest. This module defines tests using a class-based approach.

Here is an example which subclasses from django.test.TestCase, which is a subclass of unittest.TestCase that runs each test inside a transaction to provide isolation:

from django.test import TestCase
from myapp.models import Animal


class AnimalTestCase(TestCase):
    def setUp(self):
        Animal.objects.create(name="lion", sound="roar")
        Animal.objects.create(name="cat", sound="meow")

    def test_animals_can_speak(self):
        """Animals that can speak are correctly identified"""
        lion = Animal.objects.get(name="lion")
        cat = Animal.objects.get(name="cat")
        self.assertEqual(lion.speak(), 'The lion says "roar"')
        self.assertEqual(cat.speak(), 'The cat says "meow"')

When you run your tests, the default behavior of the test utility is to find all the test case classes (that is, subclasses of unittest.TestCase) in any file whose name begins with test, automatically build a test suite out of those test case classes, and run that suite.

Untuk lebih rinci tentang unittest, lihat dokumentasi Python.

Dimana seharusnya percobaan berada?

Cetakan awalan startapp membuat file tests.py di aplikasi baru. Ini mungkin baik-baik saja jika anda hanya memiliki beberapa pengujian, tetapi saat rangkaian pengujian anda berkembang, anda mungkin ingin menyusunnya kembali menjadi paket pengujian sehingga anda dapat membagi pengujian anda menjadi submodul yang berbeda seperti test_models.py, ` test_views.py`, test_forms.py, dll. Silakan pilih skema organisasi apa pun yang anda suka.

Lihat juga Menggunakan penjalan percobaan Django untuk menjalankan aplikasi digunakan kembali.

Peringatan

If your tests rely on database access such as creating or querying models, be sure to create your test classes as subclasses of django.test.TestCase rather than unittest.TestCase.

Using unittest.TestCase avoids the cost of running each test in a transaction and flushing the database, but if your tests interact with the database their behavior will vary based on the order that the test runner executes them. This can lead to unit tests that pass when run in isolation but fail when run in a suite.

Menjalankan percobaan¶

Setelah anda menulis pengujian, jalankan dengan menggunakan perintah test dari utilitas manage.py proyek anda:

$ ./manage.py test

Test discovery is based on the unittest module's built-in test discovery. By default, this will discover tests in any file named test*.py under the current working directory.

Anda dapat menentukan pengujian tertentu untuk dijalankan dengan menyediakan sejumlah "label pengujian" ke ./manage.py test. Setiap label pengujian bisa berupa jalur bertitik penuh Python ke paket, modul, subkelas TestCase, atau metode pengujian. Contohnya:

# Run all the tests in the animals.tests module
$ ./manage.py test animals.tests

# Run all the tests found within the 'animals' package
$ ./manage.py test animals

# Run just one test case class
$ ./manage.py test animals.tests.AnimalTestCase

# Run just one test method
$ ./manage.py test animals.tests.AnimalTestCase.test_animals_can_speak

You can also provide a path to a directory to discover tests below that directory:

$ ./manage.py test animals/

Anda dapat menentukan kecocokan pola nama berkas penyesuaian menggunakan pilihan -p (atau --pattern), jika file pengujian anda dinamai berbeda dari pola test*.py:

$ ./manage.py test --pattern="tests_*.py"

If you press Ctrl-C while the tests are running, the test runner will wait for the currently running test to complete and then exit gracefully. During a graceful exit the test runner will output details of any test failures, report on how many tests were run and how many errors and failures were encountered, and destroy any test databases as usual. Thus pressing Ctrl-C can be very useful if you forget to pass the --failfast option, notice that some tests are unexpectedly failing and want to get details on the failures without waiting for the full test run to complete.

If you do not want to wait for the currently running test to finish, you can press Ctrl-C a second time and the test run will halt immediately, but not gracefully. No details of the tests run before the interruption will be reported, and any test databases created by the run will not be destroyed.

Percobaan dengan peringatan diadakan

Sebaiknya jalankan pengujian anda dengan peringatan Python diaktifkan: python -Wa manage.py test. Bendera -Wa memberi tahu Python untuk menampilkan peringatan penghentian. Django, seperti banyak pustaka Python lainnya, menggunakan peringatan ini untuk menandai ketika fitur akan hilang. Itu juga mungkin menandai area dalam kode anda yang tidak sepenuhnya salah tetapi bisa mendapat manfaat dari implementasi yang lebih baik.

Basisdata percobaan¶

Tests that require a database (namely, model tests) will not use your "real" (production) database. Separate, blank databases are created for the tests.

Regardless of whether the tests pass or fail, the test databases are destroyed when all the tests have been executed.

You can prevent the test databases from being destroyed by using the test --keepdb option. This will preserve the test database between runs. If the database does not exist, it will first be created. Any migrations will also be applied in order to keep it up to date.

As described in the previous section, if a test run is forcefully interrupted, the test database may not be destroyed. On the next run, you'll be asked whether you want to reuse or destroy the database. Use the test --noinput option to suppress that prompt and automatically destroy the database. This can be useful when running tests on a continuous integration server where tests may be interrupted by a timeout, for example.

The default test database names are created by prepending test_ to the value of each NAME in DATABASES. When using SQLite, the tests will use an in-memory database by default (i.e., the database will be created in memory, bypassing the filesystem entirely!). The TEST dictionary in DATABASES offers a number of settings to configure your test database. For example, if you want to use a different database name, specify NAME in the TEST dictionary for any given database in DATABASES.

On PostgreSQL, USER will also need read access to the built-in postgres database.

Aside from using a separate database, the test runner will otherwise use all of the same database settings you have in your settings file: ENGINE, USER, HOST, etc. The test database is created by the user specified by USER, so you'll need to make sure that the given user account has sufficient privileges to create a new database on the system.

For fine-grained control over the character encoding of your test database, use the CHARSET TEST option. If you're using MySQL, you can also use the COLLATION option to control the particular collation used by the test database. See the settings documentation for details of these and other advanced settings.

If using an SQLite in-memory database with SQLite, shared cache is enabled, so you can write tests with ability to share the database between threads.

Menemukan data dari basisdata produksi anda ketika menjalankan percobaan?

If your code attempts to access the database when its modules are compiled, this will occur before the test database is set up, with potentially unexpected results. For example, if you have a database query in module-level code and a real database exists, production data could pollute your tests. It is a bad idea to have such import-time database queries in your code anyway - rewrite your code so that it doesn't do this.

Ini juga berlaku pada penerapan disesuaikan dari ready().

Lihat juga

advanced multi-db testing topics.

Urutkan dimana percobaan dijalankan¶

In order to guarantee that all TestCase code starts with a clean database, the Django test runner reorders tests in the following way:

Semua subkelas TestCase berjalan pertama.
Then, all other Django-based tests (test case classes based on SimpleTestCase, including TransactionTestCase) are run with no particular ordering guaranteed nor enforced among them.
Then any other unittest.TestCase tests (including doctests) that may alter the database without restoring it to its original state are run.

Catatan

The new ordering of tests may reveal unexpected dependencies on test case ordering. This is the case with doctests that relied on state left in the database by a given TransactionTestCase test, they must be updated to be able to run independently.

Catatan

Failures detected when loading tests are ordered before all of the above for quicker feedback. This includes things like test modules that couldn't be found or that couldn't be loaded due to syntax errors.

You may randomize and/or reverse the execution order inside groups using the test --shuffle and --reverse options. This can help with ensuring your tests are independent from each other.

Rollback emulation¶

Any initial data loaded in migrations will only be available in TestCase tests and not in TransactionTestCase tests, and additionally only on backends where transactions are supported (the most important exception being MyISAM). This is also true for tests which rely on TransactionTestCase such as LiveServerTestCase and StaticLiveServerTestCase.

Django can reload that data for you on a per-testcase basis by setting the serialized_rollback option to True in the body of the TestCase or TransactionTestCase, but note that this will slow down that test suite by approximately 3x.

Third-party apps or those developing against MyISAM will need to set this; in general, however, you should be developing your own projects against a transactional database and be using TestCase for most tests, and thus not need this setting.

The initial serialization is usually very quick, but if you wish to exclude some apps from this process (and speed up test runs slightly), you may add those apps to TEST_NON_SERIALIZED_APPS.

To prevent serialized data from being loaded twice, setting serialized_rollback=True disables the post_migrate signal when flushing the test database.

Changed in Django 5.2:

For TransactionTestCase, serialized migration data is made available during setUpClass().

Kondisi percobaan lain¶

Regardless of the value of the DEBUG setting in your configuration file, all Django tests run with DEBUG=False. This is to ensure that the observed output of your code matches what will be seen in a production setting.

Cache tidak dihapus setelah setiap pengujian, dan menjalankan manage.py test fooapp dapat memasukkan data dari pengujian ke dalam cache sistem langsung jika anda menjalankan pengujian dalam produksi karena, tidak seperti basis data, "cache pengujian" terpisah tidak digunakan. Perilaku ini may change di masa datang.

Memahami keluaran percobaan¶

When you run your tests, you'll see a number of messages as the test runner prepares itself. You can control the level of detail of these messages with the verbosity option on the command line:

Creating test database...
Creating table myapp_animal
Creating table myapp_mineral

This tells you that the test runner is creating a test database, as described in the previous section.

Once the test database has been created, Django will run your tests. If everything goes well, you'll see something like this:

----------------------------------------------------------------------
Ran 22 tests in 0.221s

OK

If there are test failures, however, you'll see full details about which tests failed:

======================================================================
FAIL: test_was_published_recently_with_future_poll (polls.tests.PollMethodTests)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/dev/mysite/polls/tests.py", line 16, in test_was_published_recently_with_future_poll
    self.assertIs(future_poll.was_published_recently(), False)
AssertionError: True is not False

----------------------------------------------------------------------
Ran 1 test in 0.003s

FAILED (failures=1)

A full explanation of this error output is beyond the scope of this document, but it's pretty intuitive. You can consult the documentation of Python's unittest library for details.

Note that the return code for the test-runner script is 1 for any number of failed tests (whether the failure was caused by an error, a failed assertion, or an unexpected success). If all the tests pass, the return code is 0. This feature is useful if you're using the test-runner script in a shell script and need to test for success or failure at that level.

Mempercepat percobaan¶

Menjalankan percobaan secara sejalan¶

As long as your tests are properly isolated, you can run them in parallel to gain a speed up on multi-core hardware. See test --parallel.

Campuran sandi¶

The default password hasher is rather slow by design. If you're authenticating many users in your tests, you may want to use a custom settings file and set the PASSWORD_HASHERS setting to a faster hashing algorithm:

PASSWORD_HASHERS = [
    "django.contrib.auth.hashers.MD5PasswordHasher",
]

Don't forget to also include in PASSWORD_HASHERS any hashing algorithm used in fixtures, if any.

Preserving the test database¶

The test --keepdb option preserves the test database between test runs. It skips the create and destroy actions which can greatly decrease the time to run tests.

Avoiding disk access for media files¶

The InMemoryStorage is a convenient way to prevent disk access for media files. All data is kept in memory, then it gets discarded after tests run.