Automated testing is an extremely useful bug-killing tool for the modern Web developer. You can use a collection of tests – a test suite – to solve, or avoid, a number of problems:
Testing a Web application is a complex task, because a Web application is made of several layers of logic – from HTTP-level request handling, to form validation and processing, to template rendering. With Django’s test-execution framework and assorted utilities, you can simulate requests, insert test data, inspect your application’s output and generally verify your code is doing what it should be doing.
The best part is, it’s really easy.
This document is split into two primary sections. First, we explain how to write tests with Django. Then, we explain how to run them.
There are two primary ways to write tests with Django, corresponding to the two test frameworks that ship in the Python standard library. The two frameworks are:
Unit tests – tests that are expressed as methods on a Python class
that subclasses unittest.TestCase
or Django’s customized
TestCase
. For example:
import unittest
class MyFuncTestCase(unittest.TestCase):
def testBasic(self):
a = ['larry', 'curly', 'moe']
self.assertEqual(my_func(a, 0), 'larry')
self.assertEqual(my_func(a, 1), 'curly')
Doctests – tests that are embedded in your functions’ docstrings and are written in a way that emulates a session of the Python interactive interpreter. For example:
def my_func(a_list, idx):
"""
>>> a = ['larry', 'curly', 'moe']
>>> my_func(a, 0)
'larry'
>>> my_func(a, 1)
'curly'
"""
return a_list[idx]
We’ll discuss choosing the appropriate test framework later, however, most experienced developers prefer unit tests. You can also use any other Python test framework, as we’ll explain in a bit.
Django’s unit tests use a Python standard library module: unittest
. This
module defines tests in class-based approach.
unittest2
Python 2.7 introduced some major changes to the unittest library, adding some extremely useful features. To ensure that every Django project can benefit from these new features, Django ships with a copy of unittest2, a copy of the Python 2.7 unittest library, backported for Python 2.5 compatibility.
To access this library, Django provides the
django.utils.unittest
module alias. If you are using Python
2.7, or you have installed unittest2 locally, Django will map the
alias to the installed version of the unittest library. Otherwise,
Django will use its own bundled version of unittest2.
To use this alias, simply use:
from django.utils import unittest
wherever you would have historically used:
import unittest
If you want to continue to use the base unittest library, you can – you just won’t get any of the nice new unittest2 features.
For a given Django application, the test runner looks for unit tests in two places:
models.py
file. The test runner looks for any subclass of
unittest.TestCase
in this module.tests.py
in the application directory – i.e., the
directory that holds models.py
. Again, the test runner looks for any
subclass of unittest.TestCase
in this module.Here is an example unittest.TestCase
subclass:
from django.utils import unittest
from myapp.models import Animal
class AnimalTestCase(unittest.TestCase):
def setUp(self):
self.lion = Animal.objects.create(name="lion", sound="roar")
self.cat = Animal.objects.create(name="cat", sound="meow")
def test_animals_can_speak(self):
"""Animals that can speak are correctly identified"""
self.assertEqual(self.lion.speak(), 'The lion says "roar"')
self.assertEqual(self.cat.speak(), 'The cat says "meow"')
When you run your tests, the default behavior of the test
utility is to find all the test cases (that is, subclasses of
unittest.TestCase
) in models.py
and tests.py
, automatically
build a test suite out of those test cases, and run that suite.
There is a second way to define the test suite for a module: if you define a
function called suite()
in either models.py
or tests.py
, the
Django test runner will use that function to construct the test suite for that
module. This follows the suggested organization for unit tests. See the
Python documentation for more details on how to construct a complex test
suite.
For more details about unittest
, see the Python documentation.
Doctests use Python’s standard doctest
module, which searches your
docstrings for statements that resemble a session of the Python interactive
interpreter. A full explanation of how doctest
works is out of the scope
of this document; read Python’s official documentation for the details.
What’s a docstring?
A good explanation of docstrings (and some guidelines for using them effectively) can be found in PEP 257:
A docstring is a string literal that occurs as the first statement in a module, function, class, or method definition. Such a docstring becomes the__doc__
special attribute of that object.
For example, this function has a docstring that describes what it does:
def add_two(num):
"Return the result of adding two to the provided number."
return num + 2
Because tests often make great documentation, putting tests directly in your docstrings is an effective way to document and test your code.
As with unit tests, for a given Django application, the test runner looks for doctests in two places:
models.py
file. You can define module-level doctests and/or a
doctest for individual models. It’s common practice to put
application-level doctests in the module docstring and model-level
doctests in the model docstrings.tests.py
in the application directory – i.e., the
directory that holds models.py
. This file is a hook for any and all
doctests you want to write that aren’t necessarily related to models.This example doctest is equivalent to the example given in the unittest section above:
# models.py
from django.db import models
class Animal(models.Model):
"""
An animal that knows how to make noise
# Create some animals
>>> lion = Animal.objects.create(name="lion", sound="roar")
>>> cat = Animal.objects.create(name="cat", sound="meow")
# Make 'em speak
>>> lion.speak()
'The lion says "roar"'
>>> cat.speak()
'The cat says "meow"'
"""
name = models.CharField(max_length=20)
sound = models.CharField(max_length=20)
def speak(self):
return 'The %s says "%s"' % (self.name, self.sound)
When you run your tests, the test runner will find this docstring, notice that portions of it look like an interactive Python session, and execute those lines while checking that the results match.
In the case of model tests, note that the test runner takes care of creating
its own test database. That is, any test that accesses a database – by
creating and saving model instances, for example – will not affect your
production database. However, the database is not refreshed between doctests,
so if your doctest requires a certain state you should consider flushing the
database or loading a fixture. (See the section on fixtures, below, for more
on this.) Note that to use this feature, the database user Django is connecting
as must have CREATE DATABASE
rights.
For more details about doctest
, see the Python documentation.
Because Django supports both of the standard Python test frameworks, it’s up to you and your tastes to decide which one to use. You can even decide to use both.
For developers new to testing, however, this choice can seem confusing. Here, then, are a few key differences to help you decide which approach is right for you:
doctest
will probably feel
more “pythonic”. It’s designed to make writing tests as easy as possible,
so it requires no overhead of writing classes or methods. You simply put
tests in docstrings. This has the added advantage of serving as
documentation (and correct documentation, at that!). However, while
doctests are good for some simple example code, they are not very good if
you want to produce either high quality, comprehensive tests or high
quality documentation. Test failures are often difficult to debug
as it can be unclear exactly why the test failed. Thus, doctests should
generally be avoided and used primarily for documentation examples only.unittest
framework will probably feel very familiar to
developers coming from Java. unittest
is inspired by Java’s JUnit,
so you’ll feel at home with this method if you’ve used JUnit or any test
framework inspired by JUnit.unittest
framework’s organization around
classes and methods. This makes it easy to abstract common tasks into
common methods. The framework also supports explicit setup and/or cleanup
routines, which give you a high level of control over the environment
in which your test cases are run.unittest
.Once you’ve written tests, run them using the test
command of
your project’s manage.py
utility:
$ ./manage.py test
By default, this will run every test in every application in
INSTALLED_APPS
. If you only want to run tests for a particular
application, add the application name to the command line. For example, if your
INSTALLED_APPS
contains 'myproject.polls'
and
'myproject.animals'
, you can run the myproject.animals
unit tests alone
with this command:
$ ./manage.py test animals
Note that we used animals
, not myproject.animals
.
You can be even more specific by naming an individual test case. To
run a single test case in an application (for example, the
AnimalTestCase
described in the “Writing unit tests” section), add
the name of the test case to the label on the command line:
$ ./manage.py test animals.AnimalTestCase
And it gets even more granular than that! To run a single test method inside a test case, add the name of the test method to the label:
$ ./manage.py test animals.AnimalTestCase.test_animals_can_speak
You can use the same rules if you’re using doctests. Django will use the
test label as a path to the test method or class that you want to run.
If your models.py
or tests.py
has a function with a doctest, or
class with a class-level doctest, you can invoke that test by appending the
name of the test method or class to the label:
$ ./manage.py test animals.classify
If you want to run the doctest for a specific method in a class, add the name of the method to the label:
$ ./manage.py test animals.Classifier.run
If you’re using a __test__
dictionary to specify doctests for a
module, Django will use the label as a key in the __test__
dictionary
for defined in models.py
and tests.py
.
Ctrl-C
.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.
Test with warnings enabled
It’s a good idea to run your tests with Python warnings enabled:
python -Wall manage.py test
. The -Wall
flag tells Python to
display deprecation warnings. Django, like many other Python libraries,
uses these warnings to flag when features are going away. It also might
flag areas in your code that aren’t strictly wrong but could benefit
from a better implementation.
If you want to run tests outside of ./manage.py test
– for example,
from a shell prompt – you will need to set up the test
environment first. Django provides a convenience method to do this:
>>> from django.test.utils import setup_test_environment
>>> setup_test_environment()
This convenience method sets up the test database, and puts other Django features into modes that allow for repeatable testing.
The call to setup_test_environment()
is made
automatically as part of the setup of ./manage.py test. You only
need to manually invoke this method if you’re not using running your
tests via Django’s test runner.
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.
By default the test databases get their names by prepending test_
to the value of the NAME
settings for the databases
defined in DATABASES
. When using the SQLite database engine
the tests will by default use an in-memory database (i.e., the
database will be created in memory, bypassing the filesystem
entirely!). If you want to use a different database name, specify
TEST_NAME
in the dictionary for any given database in
DATABASES
.
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 TEST_CHARSET
option. If you’re using
MySQL, you can also use the TEST_COLLATION
option to
control the particular collation used by the test database. See the
settings documentation for details of these
advanced settings.
If you’re testing a multiple database configuration with master/slave replication, this strategy of creating test databases poses a problem. When the test databases are created, there won’t be any replication, and as a result, data created on the master won’t be seen on the slave.
To compensate for this, Django allows you to define that a database is a test mirror. Consider the following (simplified) example database configuration:
DATABASES = {
'default': {
'ENGINE': 'django.db.backends.mysql',
'NAME': 'myproject',
'HOST': 'dbmaster',
# ... plus some other settings
},
'slave': {
'ENGINE': 'django.db.backends.mysql',
'NAME': 'myproject',
'HOST': 'dbslave',
'TEST_MIRROR': 'default'
# ... plus some other settings
}
}
In this setup, we have two database servers: dbmaster
, described
by the database alias default
, and dbslave
described by the
alias slave
. As you might expect, dbslave
has been configured
by the database administrator as a read slave of dbmaster
, so in
normal activity, any write to default
will appear on slave
.
If Django created two independent test databases, this would break any
tests that expected replication to occur. However, the slave
database has been configured as a test mirror (using the
TEST_MIRROR
setting), indicating that under testing,
slave
should be treated as a mirror of default
.
When the test environment is configured, a test version of slave
will not be created. Instead the connection to slave
will be redirected to point at default
. As a result, writes to
default
will appear on slave
– but because they are actually
the same database, not because there is data replication between the
two databases.
By default, Django will always create the default
database first.
However, no guarantees are made on the creation order of any other
databases in your test setup.
If your database configuration requires a specific creation order, you
can specify the dependencies that exist using the
TEST_DEPENDENCIES
setting. Consider the following
(simplified) example database configuration:
DATABASES = {
'default': {
# ... db settings
'TEST_DEPENDENCIES': ['diamonds']
},
'diamonds': {
# ... db settings
},
'clubs': {
# ... db settings
'TEST_DEPENDENCIES': ['diamonds']
},
'spades': {
# ... db settings
'TEST_DEPENDENCIES': ['diamonds','hearts']
},
'hearts': {
# ... db settings
'TEST_DEPENDENCIES': ['diamonds','clubs']
}
}
Under this configuration, the diamonds
database will be created first,
as it is the only database alias without dependencies. The default
and
clubs
alias will be created next (although the order of creation of this
pair is not guaranteed); then hearts
; and finally spades
.
If there are any circular dependencies in the
TEST_DEPENDENCIES
definition, an ImproperlyConfigured
exception will be raised.
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.
Caches are not cleared after each test, and running “manage.py test fooapp” can insert data from the tests into the cache of a live system if you run your tests in production because, unlike databases, a separate “test cache” is not used. This behavior may change in the future.
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
Loading 'initial_data' fixtures...
No fixtures found.
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: Doctest: ellington.core.throttle.models
----------------------------------------------------------------------
Traceback (most recent call last):
File "/dev/django/test/doctest.py", line 2153, in runTest
raise self.failureException(self.format_failure(new.getvalue()))
AssertionError: Failed doctest test for myapp.models
File "/dev/myapp/models.py", line 0, in models
----------------------------------------------------------------------
File "/dev/myapp/models.py", line 14, in myapp.models
Failed example:
throttle.check("actor A", "action one", limit=2, hours=1)
Expected:
True
Got:
False
----------------------------------------------------------------------
Ran 2 tests in 0.048s
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 and erroneous tests. 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.
In recent versions of Django, the default password hasher is rather slow by
design. If during your tests you are authenticating many users, 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.
Code coverage describes how much source code has been tested. It shows which parts of your code are being exercised by tests and which are not. It’s an important part of testing applications, so it’s strongly recommended to check the coverage of your tests.
Django can be easily integrated with coverage.py, a tool for measuring code
coverage of Python programs. First, install coverage.py. Next, run the
following from your project folder containing manage.py
:
coverage run --source='.' manage.py test myapp
This runs your tests and collects coverage data of the executed files in your project. You can see a report of this data by typing following command:
coverage report
Note that some Django code was executed while running tests, but it is not
listed here because of the source
flag passed to the previous command.
For more options like annotated HTML listings detailing missed lines, see the coverage.py docs.
Django provides a small set of tools that come in handy when writing tests.
The test client is a Python class that acts as a dummy Web browser, allowing you to test your views and interact with your Django-powered application programmatically.
Some of the things you can do with the test client are:
Note that the test client is not intended to be a replacement for Selenium or other “in-browser” frameworks. Django’s test client has a different focus. In short:
LiveServerTestCase
for more details.A comprehensive test suite should use a combination of both test types.
To use the test client, instantiate django.test.client.Client
and retrieve
Web pages:
>>> from django.test.client import Client
>>> c = Client()
>>> response = c.post('/login/', {'username': 'john', 'password': 'smith'})
>>> response.status_code
200
>>> response = c.get('/customer/details/')
>>> response.content
'<!DOCTYPE html...'
As this example suggests, you can instantiate Client
from within a session
of the Python interactive interpreter.
Note a few important things about how the test client works:
The test client does not require the Web server to be running. In fact, it will run just fine with no Web server running at all! That’s because it avoids the overhead of HTTP and deals directly with the Django framework. This helps make the unit tests run quickly.
When retrieving pages, remember to specify the path of the URL, not the whole domain. For example, this is correct:
>>> c.get('/login/')
This is incorrect:
>>> c.get('http://www.example.com/login/')
The test client is not capable of retrieving Web pages that are not
powered by your Django project. If you need to retrieve other Web pages,
use a Python standard library module such as urllib
or
urllib2
.
To resolve URLs, the test client uses whatever URLconf is pointed-to by
your ROOT_URLCONF
setting.
Although the above example would work in the Python interactive interpreter, some of the test client’s functionality, notably the template-related functionality, is only available while tests are running.
The reason for this is that Django’s test runner performs a bit of black magic in order to determine which template was loaded by a given view. This black magic (essentially a patching of Django’s template system in memory) only happens during test running.
By default, the test client will disable any CSRF checks performed by your site.
If, for some reason, you want the test client to perform CSRF
checks, you can create an instance of the test client that
enforces CSRF checks. To do this, pass in the
enforce_csrf_checks
argument when you construct your
client:
>>> from django.test import Client
>>> csrf_client = Client(enforce_csrf_checks=True)
Use the django.test.client.Client
class to make requests. It requires no
arguments at time of construction:
Client
¶Once you have a Client
instance, you can call any of the following
methods:
get
(path, data={}, follow=False, **extra)¶Makes a GET request on the provided path
and returns a Response
object, which is documented below.
The key-value pairs in the data
dictionary are used to create a GET
data payload. For example:
>>> c = Client()
>>> c.get('/customers/details/', {'name': 'fred', 'age': 7})
...will result in the evaluation of a GET request equivalent to:
/customers/details/?name=fred&age=7
The extra
keyword arguments parameter can be used to specify
headers to be sent in the request. For example:
>>> c = Client()
>>> c.get('/customers/details/', {'name': 'fred', 'age': 7},
... HTTP_X_REQUESTED_WITH='XMLHttpRequest')
...will send the HTTP header HTTP_X_REQUESTED_WITH
to the
details view, which is a good way to test code paths that use the
django.http.HttpRequest.is_ajax()
method.
CGI specification
The headers sent via **extra
should follow CGI specification.
For example, emulating a different “Host” header as sent in the
HTTP request from the browser to the server should be passed
as HTTP_HOST
.
If you already have the GET arguments in URL-encoded form, you can use that encoding instead of using the data argument. For example, the previous GET request could also be posed as:
>>> c = Client()
>>> c.get('/customers/details/?name=fred&age=7')
If you provide a URL with both an encoded GET data and a data argument, the data argument will take precedence.
If you set follow
to True
the client will follow any redirects
and a redirect_chain
attribute will be set in the response object
containing tuples of the intermediate urls and status codes.
If you had an url /redirect_me/
that redirected to /next/
, that
redirected to /final/
, this is what you’d see:
>>> response = c.get('/redirect_me/', follow=True)
>>> response.redirect_chain
[(u'http://testserver/next/', 302), (u'http://testserver/final/', 302)]
post
(path, data={}, content_type=MULTIPART_CONTENT, follow=False, **extra)¶Makes a POST request on the provided path
and returns a
Response
object, which is documented below.
The key-value pairs in the data
dictionary are used to submit POST
data. For example:
>>> c = Client()
>>> c.post('/login/', {'name': 'fred', 'passwd': 'secret'})
...will result in the evaluation of a POST request to this URL:
/login/
...with this POST data:
name=fred&passwd=secret
If you provide content_type
(e.g. text/xml for an XML
payload), the contents of data
will be sent as-is in the POST
request, using content_type
in the HTTP Content-Type
header.
If you don’t provide a value for content_type
, the values in
data
will be transmitted with a content type of
multipart/form-data. In this case, the key-value pairs in
data
will be encoded as a multipart message and used to create the
POST data payload.
To submit multiple values for a given key – for example, to specify
the selections for a <select multiple>
– provide the values as a
list or tuple for the required key. For example, this value of data
would submit three selected values for the field named choices
:
{'choices': ('a', 'b', 'd')}
Submitting files is a special case. To POST a file, you need only provide the file field name as a key, and a file handle to the file you wish to upload as a value. For example:
>>> c = Client()
>>> f = open('wishlist.doc')
>>> c.post('/customers/wishes/', {'name': 'fred', 'attachment': f})
>>> f.close()
(The name attachment
here is not relevant; use whatever name your
file-processing code expects.)
Note that if you wish to use the same file handle for multiple
post()
calls then you will need to manually reset the file
pointer between posts. The easiest way to do this is to
manually close the file after it has been provided to
post()
, as demonstrated above.
You should also ensure that the file is opened in a way that
allows the data to be read. If your file contains binary data
such as an image, this means you will need to open the file in
rb
(read binary) mode.
The extra
argument acts the same as for Client.get()
.
If the URL you request with a POST contains encoded parameters, these parameters will be made available in the request.GET data. For example, if you were to make the request:
>>> c.post('/login/?visitor=true', {'name': 'fred', 'passwd': 'secret'})
... the view handling this request could interrogate request.POST to retrieve the username and password, and could interrogate request.GET to determine if the user was a visitor.
If you set follow
to True
the client will follow any redirects
and a redirect_chain
attribute will be set in the response object
containing tuples of the intermediate urls and status codes.
head
(path, data={}, follow=False, **extra)¶Makes a HEAD request on the provided path
and returns a Response
object. Useful for testing RESTful interfaces. Acts just like
Client.get()
except it does not return a message body.
If you set follow
to True
the client will follow any redirects
and a redirect_chain
attribute will be set in the response object
containing tuples of the intermediate urls and status codes.
options
(path, data={}, follow=False, **extra)¶Makes an OPTIONS request on the provided path
and returns a
Response
object. Useful for testing RESTful interfaces.
If you set follow
to True
the client will follow any redirects
and a redirect_chain
attribute will be set in the response object
containing tuples of the intermediate urls and status codes.
The extra
argument acts the same as for Client.get()
.
put
(path, data={}, content_type=MULTIPART_CONTENT, follow=False, **extra)¶Makes a PUT request on the provided path
and returns a
Response
object. Useful for testing RESTful interfaces. Acts just
like Client.post()
except with the PUT request method.
If you set follow
to True
the client will follow any redirects
and a redirect_chain
attribute will be set in the response object
containing tuples of the intermediate urls and status codes.
delete
(path, follow=False, **extra)¶Makes an DELETE request on the provided path
and returns a
Response
object. Useful for testing RESTful interfaces.
If you set follow
to True
the client will follow any redirects
and a redirect_chain
attribute will be set in the response object
containing tuples of the intermediate urls and status codes.
The extra
argument acts the same as for Client.get()
.
login
(**credentials)¶If your site uses Django’s authentication system
and you deal with logging in users, you can use the test client’s
login()
method to simulate the effect of a user logging into the
site.
After you call this method, the test client will have all the cookies and session data required to pass any login-based tests that may form part of a view.
The format of the credentials
argument depends on which
authentication backend you’re using
(which is configured by your AUTHENTICATION_BACKENDS
setting). If you’re using the standard authentication backend provided
by Django (ModelBackend
), credentials
should be the user’s
username and password, provided as keyword arguments:
>>> c = Client()
>>> c.login(username='fred', password='secret')
# Now you can access a view that's only available to logged-in users.
If you’re using a different authentication backend, this method may
require different credentials. It requires whichever credentials are
required by your backend’s authenticate()
method.
login()
returns True
if it the credentials were accepted and
login was successful.
Finally, you’ll need to remember to create user accounts before you can
use this method. As we explained above, the test runner is executed
using a test database, which contains no users by default. As a result,
user accounts that are valid on your production site will not work
under test conditions. You’ll need to create users as part of the test
suite – either manually (using the Django model API) or with a test
fixture. Remember that if you want your test user to have a password,
you can’t set the user’s password by setting the password attribute
directly – you must use the
set_password()
function to
store a correctly hashed password. Alternatively, you can use the
create_user()
helper
method to create a new user with a correctly hashed password.
logout
()¶If your site uses Django’s authentication system,
the logout()
method can be used to simulate the effect of a user
logging out of your site.
After you call this method, the test client will have all the cookies and session data cleared to defaults. Subsequent requests will appear to come from an AnonymousUser.
The get()
and post()
methods both return a Response
object. This
Response
object is not the same as the HttpResponse
object returned
Django views; the test response object has some additional data useful for
test code to verify.
Specifically, a Response
object has the following attributes:
Response
¶client
¶The test client that was used to make the request that resulted in the response.
content
¶The body of the response, as a string. This is the final page content as rendered by the view, or any error message.
context
¶The template Context
instance that was used to render the template that
produced the response content.
If the rendered page used multiple templates, then context
will be a
list of Context
objects, in the order in which they were rendered.
Regardless of the number of templates used during rendering, you can
retrieve context values using the []
operator. For example, the
context variable name
could be retrieved using:
>>> response = client.get('/foo/')
>>> response.context['name']
'Arthur'
request
¶The request data that stimulated the response.
status_code
¶The HTTP status of the response, as an integer. See RFC 2616#section-10 for a full list of HTTP status codes.
templates
¶A list of Template
instances used to render the final content, in
the order they were rendered. For each template in the list, use
template.name
to get the template’s file name, if the template was
loaded from a file. (The name is a string such as
'admin/index.html'
.)
You can also use dictionary syntax on the response object to query the value
of any settings in the HTTP headers. For example, you could determine the
content type of a response using response['Content-Type']
.
If you point the test client at a view that raises an exception, that exception
will be visible in the test case. You can then use a standard try ... except
block or assertRaises()
to test for exceptions.
The only exceptions that are not visible to the test client are Http404
,
PermissionDenied
and SystemExit
. Django catches these exceptions
internally and converts them into the appropriate HTTP response codes. In these
cases, you can check response.status_code
in your test.
The test client is stateful. If a response returns a cookie, then that cookie
will be stored in the test client and sent with all subsequent get()
and
post()
requests.
Expiration policies for these cookies are not followed. If you want a cookie
to expire, either delete it manually or create a new Client
instance (which
will effectively delete all cookies).
A test client has two attributes that store persistent state information. You can access these properties as part of a test condition.
A Python SimpleCookie
object, containing the current values
of all the client cookies. See the documentation of the Cookie
module
for more.
Client.
session
¶A dictionary-like object containing session information. See the session documentation for full details.
To modify the session and then save it, it must be stored in a variable
first (because a new SessionStore
is created every time this property
is accessed):
def test_something(self):
session = self.client.session
session['somekey'] = 'test'
session.save()
The following is a simple unit test using the test client:
from django.utils import unittest
from django.test.client import Client
class SimpleTest(unittest.TestCase):
def setUp(self):
# Every test needs a client.
self.client = Client()
def test_details(self):
# Issue a GET request.
response = self.client.get('/customer/details/')
# Check that the response is 200 OK.
self.assertEqual(response.status_code, 200)
# Check that the rendered context contains 5 customers.
self.assertEqual(len(response.context['customers']), 5)
RequestFactory
¶The RequestFactory
shares the same API as
the test client. However, instead of behaving like a browser, the
RequestFactory provides a way to generate a request instance that can
be used as the first argument to any view. This means you can test a
view function the same way as you would test any other function – as
a black box, with exactly known inputs, testing for specific outputs.
The API for the RequestFactory
is a slightly
restricted subset of the test client API:
get()
,
post()
, put()
,
delete()
, head()
and
options()
.follows
. Since this is just a factory for producing
requests, it’s up to you to handle the response.The following is a simple unit test using the request factory:
from django.utils import unittest
from django.test.client import RequestFactory
class SimpleTest(unittest.TestCase):
def setUp(self):
# Every test needs access to the request factory.
self.factory = RequestFactory()
def test_details(self):
# Create an instance of a GET request.
request = self.factory.get('/customer/details')
# Test my_view() as if it were deployed at /customer/details
response = my_view(request)
self.assertEqual(response.status_code, 200)
Normal Python unit test classes extend a base class of
unittest.TestCase
. Django provides a few extensions of this base class:
TestCase
¶This class provides some additional capabilities that can be useful for testing Web sites.
Converting a normal unittest.TestCase
to a Django TestCase
is
easy: just change the base class of your test from unittest.TestCase
to
django.test.TestCase
. All of the standard Python unit test
functionality will continue to be available, but it will be augmented with some
useful additions, including:
TestCase
inherits from TransactionTestCase
.
TransactionTestCase
¶Django TestCase
classes make use of database transaction facilities, if
available, to speed up the process of resetting the database to a known state
at the beginning of each test. A consequence of this, however, is that the
effects of transaction commit and rollback cannot be tested by a Django
TestCase
class. If your test requires testing of such transactional
behavior, you should use a Django TransactionTestCase
.
TransactionTestCase
and TestCase
are identical except for the manner
in which the database is reset to a known state and the ability for test code
to test the effects of commit and rollback. A TransactionTestCase
resets
the database before the test runs by truncating all tables and reloading
initial data. A TransactionTestCase
may call commit and rollback and
observe the effects of these calls on the database.
A TestCase
, on the other hand, does not truncate tables and reload initial
data at the beginning of a test. Instead, it encloses the test code in a
database transaction that is rolled back at the end of the test. It also
prevents the code under test from issuing any commit or rollback operations
on the database, to ensure that the rollback at the end of the test restores
the database to its initial state. In order to guarantee that all TestCase
code starts with a clean database, the Django test runner runs all TestCase
tests first, before any other tests (e.g. doctests) that may alter the
database without restoring it to its original state.
When running on a database that does not support rollback (e.g. MySQL with the
MyISAM storage engine), TestCase
falls back to initializing the database
by truncating tables and reloading initial data.
TransactionTestCase
inherits from SimpleTestCase
.
Note
The TestCase
use of rollback to un-do the effects of the test code
may reveal previously-undetected errors in test code. For example,
test code that assumes primary keys values will be assigned starting at
one may find that assumption no longer holds true when rollbacks instead
of table truncation are being used to reset the database. Similarly,
the reordering of tests so that all TestCase
classes run first may
reveal unexpected dependencies on test case ordering. In such cases a
quick fix is to switch the TestCase
to a TransactionTestCase
.
A better long-term fix, that allows the test to take advantage of the
speed benefit of TestCase
, is to fix the underlying test problem.
SimpleTestCase
¶A very thin subclass of unittest.TestCase
, it extends it with some
basic functionality like:
raises a certain exception
.Testing form field rendering
.If you need any of the other more complex and heavyweight Django-specific features like:
client
Client
.fixtures
.URL maps
.then you should use TransactionTestCase
or
TestCase
instead.
SimpleTestCase
inherits from django.utils.unittest.TestCase
.
TestCase.
client
¶Every test case in a django.test.TestCase
instance has access to an
instance of a Django test client. This client can be accessed as
self.client
. This client is recreated for each test, so you don’t have to
worry about state (such as cookies) carrying over from one test to another.
This means, instead of instantiating a Client
in each test:
from django.utils import unittest
from django.test.client import Client
class SimpleTest(unittest.TestCase):
def test_details(self):
client = Client()
response = client.get('/customer/details/')
self.assertEqual(response.status_code, 200)
def test_index(self):
client = Client()
response = client.get('/customer/index/')
self.assertEqual(response.status_code, 200)
...you can just refer to self.client
, like so:
from django.test import TestCase
class SimpleTest(TestCase):
def test_details(self):
response = self.client.get('/customer/details/')
self.assertEqual(response.status_code, 200)
def test_index(self):
response = self.client.get('/customer/index/')
self.assertEqual(response.status_code, 200)
TestCase.
client_class
¶If you want to use a different Client
class (for example, a subclass
with customized behavior), use the client_class
class
attribute:
from django.test import TestCase
from django.test.client import Client
class MyTestClient(Client):
# Specialized methods for your environment...
class MyTest(TestCase):
client_class = MyTestClient
def test_my_stuff(self):
# Here self.client is an instance of MyTestClient...
TestCase.
fixtures
¶A test case for a database-backed Web site isn’t much use if there isn’t any
data in the database. To make it easy to put test data into the database,
Django’s custom TestCase
class provides a way of loading fixtures.
A fixture is a collection of data that Django knows how to import into a database. For example, if your site has user accounts, you might set up a fixture of fake user accounts in order to populate your database during tests.
The most straightforward way of creating a fixture is to use the
manage.py dumpdata
command. This assumes you
already have some data in your database. See the dumpdata
documentation
for more details.
Note
If you’ve ever run manage.py syncdb
, you’ve
already used a fixture without even knowing it! When you call
syncdb
in the database for the first time, Django
installs a fixture called initial_data
. This gives you a way
of populating a new database with any initial data, such as a
default set of categories.
Fixtures with other names can always be installed manually using
the manage.py loaddata
command.
Initial SQL data and testing
Django provides a second way to insert initial data into models – the custom SQL hook. However, this technique cannot be used to provide initial data for testing purposes. Django’s test framework flushes the contents of the test database after each test; as a result, any data added using the custom SQL hook will be lost.
Once you’ve created a fixture and placed it in a fixtures
directory in one
of your INSTALLED_APPS
, you can use it in your unit tests by
specifying a fixtures
class attribute on your django.test.TestCase
subclass:
from django.test import TestCase
from myapp.models import Animal
class AnimalTestCase(TestCase):
fixtures = ['mammals.json', 'birds']
def setUp(self):
# Test definitions as before.
call_setup_methods()
def testFluffyAnimals(self):
# A test that uses the fixtures.
call_some_test_code()
Here’s specifically what will happen:
setUp()
is run, Django will
flush the database, returning the database to the state it was in
directly after syncdb
was called.mammals
, followed by any fixture named
birds
. See the loaddata
documentation for more
details on defining and installing fixtures.This flush/load procedure is repeated for each test in the test case, so you can be certain that the outcome of a test will not be affected by another test, or by the order of test execution.
TestCase.
urls
¶If your application provides views, you may want to include tests that use the test client to exercise those views. However, an end user is free to deploy the views in your application at any URL of their choosing. This means that your tests can’t rely upon the fact that your views will be available at a particular URL.
In order to provide a reliable URL space for your test,
django.test.TestCase
provides the ability to customize the URLconf
configuration for the duration of the execution of a test suite. If your
TestCase
instance defines an urls
attribute, the TestCase
will use
the value of that attribute as the ROOT_URLCONF
for the duration
of that test.
For example:
from django.test import TestCase
class TestMyViews(TestCase):
urls = 'myapp.test_urls'
def testIndexPageView(self):
# Here you'd test your view using ``Client``.
call_some_test_code()
This test case will use the contents of myapp.test_urls
as the
URLconf for the duration of the test case.
TestCase.
multi_db
¶Django sets up a test database corresponding to every database that is
defined in the DATABASES
definition in your settings
file. However, a big part of the time taken to run a Django TestCase
is consumed by the call to flush
that ensures that you have a
clean database at the start of each test run. If you have multiple
databases, multiple flushes are required (one for each database),
which can be a time consuming activity – especially if your tests
don’t need to test multi-database activity.
As an optimization, Django only flushes the default
database at
the start of each test run. If your setup contains multiple databases,
and you have a test that requires every database to be clean, you can
use the multi_db
attribute on the test suite to request a full
flush.
For example:
class TestMyViews(TestCase):
multi_db = True
def testIndexPageView(self):
call_some_test_code()
This test case will flush all the test databases before running
testIndexPageView
.
TestCase.
settings
()¶For testing purposes it’s often useful to change a setting temporarily and
revert to the original value after running the testing code. For this use case
Django provides a standard Python context manager (see PEP 343)
settings()
, which can be used like this:
from django.test import TestCase
class LoginTestCase(TestCase):
def test_login(self):
# First check for the default behavior
response = self.client.get('/sekrit/')
self.assertRedirects(response, '/accounts/login/?next=/sekrit/')
# Then override the LOGIN_URL setting
with self.settings(LOGIN_URL='/other/login/'):
response = self.client.get('/sekrit/')
self.assertRedirects(response, '/other/login/?next=/sekrit/')
This example will override the LOGIN_URL
setting for the code
in the with
block and reset its value to the previous state afterwards.
override_settings
()¶In case you want to override a setting for just one test method or even the
whole TestCase
class, Django provides the
override_settings()
decorator (see PEP 318). It’s
used like this:
from django.test import TestCase
from django.test.utils import override_settings
class LoginTestCase(TestCase):
@override_settings(LOGIN_URL='/other/login/')
def test_login(self):
response = self.client.get('/sekrit/')
self.assertRedirects(response, '/other/login/?next=/sekrit/')
The decorator can also be applied to test case classes:
from django.test import TestCase
from django.test.utils import override_settings
class LoginTestCase(TestCase):
def test_login(self):
response = self.client.get('/sekrit/')
self.assertRedirects(response, '/other/login/?next=/sekrit/')
LoginTestCase = override_settings(LOGIN_URL='/other/login/')(LoginTestCase)
Note
When given a class, the decorator modifies the class directly and
returns it; it doesn’t create and return a modified copy of it. So if
you try to tweak the above example to assign the return value to a
different name than LoginTestCase
, you may be surprised to find that
the original LoginTestCase
is still equally affected by the
decorator.
On Python 2.6 and higher you can also use the well known decorator syntax to decorate the class:
from django.test import TestCase
from django.test.utils import override_settings
@override_settings(LOGIN_URL='/other/login/')
class LoginTestCase(TestCase):
def test_login(self):
response = self.client.get('/sekrit/')
self.assertRedirects(response, '/other/login/?next=/sekrit/')
Note
When overriding settings, make sure to handle the cases in which your app’s
code uses a cache or similar feature that retains state even if the
setting is changed. Django provides the
django.test.signals.setting_changed
signal that lets you register
callbacks to clean up and otherwise reset state when settings are changed.
Note that this signal isn’t currently used by Django itself, so changing
built-in settings may not yield the results you expect.
If you use Django’s custom TestCase
class, the test runner will clear the
contents of the test email outbox at the start of each test case.
For more detail on email services during tests, see Email services.
msg_prefix
argument.As Python’s normal unittest.TestCase
class implements assertion methods
such as assertTrue()
and
assertEqual()
, Django’s custom TestCase
class
provides a number of custom assertion methods that are useful for testing Web
applications:
The failure messages given by most of these assertion methods can be customized
with the msg_prefix
argument. This string will be prefixed to any failure
message generated by the assertion. This allows you to provide additional
details that may help you to identify the location and cause of an failure in
your test suite.
SimpleTestCase.
assertRaisesMessage
(expected_exception, expected_message, callable_obj=None, *args, **kwargs)¶Asserts that execution of callable callable_obj
raised the
expected_exception
exception and that such exception has an
expected_message
representation. Any other outcome is reported as a
failure. Similar to unittest’s assertRaisesRegexp()
with the difference that expected_message
isn’t a regular expression.
SimpleTestCase.
assertFieldOutput
(self, fieldclass, valid, invalid, field_args=None, field_kwargs=None, empty_value=u'')¶Asserts that a form field behaves correctly with various inputs.
Parameters: |
|
---|
For example, the following code tests that an EmailField
accepts
“a@a.com” as a valid email address, but rejects “aaa” with a reasonable
error message:
self.assertFieldOutput(EmailField, {'a@a.com': 'a@a.com'}, {'aaa': [u'Enter a valid e-mail address.']})
TestCase.
assertContains
(response, text, count=None, status_code=200, msg_prefix='', html=False)¶Asserts that a Response
instance produced the given status_code
and
that text
appears in the content of the response. If count
is
provided, text
must occur exactly count
times in the response.
Set html
to True
to handle text
as HTML. The comparison with
the response content will be based on HTML semantics instead of
character-by-character equality. Whitespace is ignored in most cases,
attribute ordering is not significant. See
assertHTMLEqual()
for more details.
TestCase.
assertNotContains
(response, text, status_code=200, msg_prefix='', html=False)¶Asserts that a Response
instance produced the given status_code
and
that text
does not appears in the content of the response.
Set html
to True
to handle text
as HTML. The comparison with
the response content will be based on HTML semantics instead of
character-by-character equality. Whitespace is ignored in most cases,
attribute ordering is not significant. See
assertHTMLEqual()
for more details.
TestCase.
assertFormError
(response, form, field, errors, msg_prefix='')¶Asserts that a field on a form raises the provided list of errors when rendered on the form.
form
is the name the Form
instance was given in the template
context.
field
is the name of the field on the form to check. If field
has a value of None
, non-field errors (errors you can access via
form.non_field_errors()
) will be checked.
errors
is an error string, or a list of error strings, that are
expected as a result of form validation.
TestCase.
assertTemplateUsed
(response, template_name, msg_prefix='')¶Asserts that the template with the given name was used in rendering the response.
The name is a string such as 'admin/index.html'
.
You can use this as a context manager, like this:
# This is necessary in Python 2.5 to enable the with statement.
# In 2.6 and up, it's not necessary.
from __future__ import with_statement
with self.assertTemplateUsed('index.html'):
render_to_string('index.html')
with self.assertTemplateUsed(template_name='index.html'):
render_to_string('index.html')
TestCase.
assertTemplateNotUsed
(response, template_name, msg_prefix='')¶Asserts that the template with the given name was not used in rendering the response.
You can use this as a context manager in the same way as
assertTemplateUsed()
.
TestCase.
assertRedirects
(response, expected_url, status_code=302, target_status_code=200, msg_prefix='')¶Asserts that the response return a status_code
redirect status, it
redirected to expected_url
(including any GET data), and the final
page was received with target_status_code
.
If your request used the follow
argument, the expected_url
and
target_status_code
will be the url and status code for the final
point of the redirect chain.
TestCase.
assertQuerysetEqual
(qs, values, transform=repr, ordered=True)¶Asserts that a queryset qs
returns a particular list of values values
.
The comparison of the contents of qs
and values
is performed using
the function transform
; by default, this means that the repr()
of
each value is compared. Any other callable can be used if repr()
doesn’t
provide a unique or helpful comparison.
By default, the comparison is also ordering dependent. If qs
doesn’t
provide an implicit ordering, you can set the ordered
parameter to
False
, which turns the comparison into a Python set comparison.
ordered
parameter is new in version 1.4. In earlier versions,
you would need to ensure the queryset is ordered consistently, possibly
via an explicit order_by()
call on the queryset prior to
comparison.TestCase.
assertNumQueries
(num, func, *args, **kwargs)¶Asserts that when func
is called with *args
and **kwargs
that
num
database queries are executed.
If a "using"
key is present in kwargs
it is used as the database
alias for which to check the number of queries. If you wish to call a
function with a using
parameter you can do it by wrapping the call with
a lambda
to add an extra parameter:
self.assertNumQueries(7, lambda: my_function(using=7))
If you’re using Python 2.5 or greater you can also use this as a context manager:
# This is necessary in Python 2.5 to enable the with statement, in 2.6
# and up it is no longer necessary.
from __future__ import with_statement
with self.assertNumQueries(2):
Person.objects.create(name="Aaron")
Person.objects.create(name="Daniel")
SimpleTestCase.
assertHTMLEqual
(html1, html2, msg=None)¶Asserts that the strings html1
and html2
are equal. The comparison
is based on HTML semantics. The comparison takes following things into
account:
The following examples are valid tests and don’t raise any
AssertionError
:
self.assertHTMLEqual('<p>Hello <b>world!</p>',
'''<p>
Hello <b>world! <b/>
</p>''')
self.assertHTMLEqual(
'<input type="checkbox" checked="checked" id="id_accept_terms" />',
'<input id="id_accept_terms" type='checkbox' checked>')
html1
and html2
must be valid HTML. An AssertionError
will be
raised if one of them cannot be parsed.
SimpleTestCase.
assertHTMLNotEqual
(html1, html2, msg=None)¶Asserts that the strings html1
and html2
are not equal. The
comparison is based on HTML semantics. See
assertHTMLEqual()
for details.
html1
and html2
must be valid HTML. An AssertionError
will be
raised if one of them cannot be parsed.
If any of your Django views send email using Django’s email functionality, you probably don’t want to send email each time you run a test using that view. For this reason, Django’s test runner automatically redirects all Django-sent email to a dummy outbox. This lets you test every aspect of sending email – from the number of messages sent to the contents of each message – without actually sending the messages.
The test runner accomplishes this by transparently replacing the normal email backend with a testing backend. (Don’t worry – this has no effect on any other email senders outside of Django, such as your machine’s mail server, if you’re running one.)
django.core.mail.
outbox
¶During test running, each outgoing email is saved in
django.core.mail.outbox
. This is a simple list of all
EmailMessage
instances that have been sent.
The outbox
attribute is a special attribute that is created only when
the locmem
email backend is used. It doesn’t normally exist as part of the
django.core.mail
module and you can’t import it directly. The code
below shows how to access this attribute correctly.
Here’s an example test that examines django.core.mail.outbox
for length
and contents:
from django.core import mail
from django.test import TestCase
class EmailTest(TestCase):
def test_send_email(self):
# Send message.
mail.send_mail('Subject here', 'Here is the message.',
'from@example.com', ['to@example.com'],
fail_silently=False)
# Test that one message has been sent.
self.assertEqual(len(mail.outbox), 1)
# Verify that the subject of the first message is correct.
self.assertEqual(mail.outbox[0].subject, 'Subject here')
As noted previously, the test outbox is emptied
at the start of every test in a Django TestCase
. To empty the outbox
manually, assign the empty list to mail.outbox
:
from django.core import mail
# Empty the test outbox
mail.outbox = []
The unittest library provides the @skipIf
and
@skipUnless
decorators to allow you to skip tests
if you know ahead of time that those tests are going to fail under certain
conditions.
For example, if your test requires a particular optional library in order to
succeed, you could decorate the test case with @skipIf
. Then, the test runner will report that the test wasn’t
executed and why, instead of failing the test or omitting the test altogether.
To supplement these test skipping behaviors, Django provides two additional skip decorators. Instead of testing a generic boolean, these decorators check the capabilities of the database, and skip the test if the database doesn’t support a specific named feature.
The decorators use a string identifier to describe database features.
This string corresponds to attributes of the database connection
features class. See BaseDatabaseFeatures
class for a full list of database features that can be used as a basis
for skipping tests.
skipIfDBFeature
(feature_name_string)¶Skip the decorated test if the named database feature is supported.
For example, the following test will not be executed if the database supports transactions (e.g., it would not run under PostgreSQL, but it would under MySQL with MyISAM tables):
class MyTests(TestCase):
@skipIfDBFeature('supports_transactions')
def test_transaction_behavior(self):
# ... conditional test code
skipUnlessDBFeature
(feature_name_string)¶Skip the decorated test if the named database feature is not supported.
For example, the following test will only be executed if the database supports transactions (e.g., it would run under PostgreSQL, but not under MySQL with MyISAM tables):
class MyTests(TestCase):
@skipUnlessDBFeature('supports_transactions')
def test_transaction_behavior(self):
# ... conditional test code
LiveServerTestCase
¶LiveServerTestCase
does basically the same as
TransactionTestCase
with one extra feature: it launches a
live Django server in the background on setup, and shuts it down on teardown.
This allows the use of automated test clients other than the
Django dummy client such as, for example, the Selenium
client, to execute a series of functional tests inside a browser and simulate a
real user’s actions.
By default the live server’s address is ‘localhost:8081’ and the full URL
can be accessed during the tests with self.live_server_url
. If you’d like
to change the default address (in the case, for example, where the 8081 port is
already taken) then you may pass a different one to the test
command
via the --liveserver
option, for example:
./manage.py test --liveserver=localhost:8082
Another way of changing the default server address is by setting the DJANGO_LIVE_TEST_SERVER_ADDRESS environment variable somewhere in your code (for example, in a custom test runner):
import os
os.environ['DJANGO_LIVE_TEST_SERVER_ADDRESS'] = 'localhost:8082'
In the case where the tests are run by multiple processes in parallel (for example, in the context of several simultaneous continuous integration builds), the processes will compete for the same address, and therefore your tests might randomly fail with an “Address already in use” error. To avoid this problem, you can pass a comma-separated list of ports or ranges of ports (at least as many as the number of potential parallel processes). For example:
./manage.py test --liveserver=localhost:8082,8090-8100,9000-9200,7041
Then, during test execution, each new live test server will try every specified port until it finds one that is free and takes it.
To demonstrate how to use LiveServerTestCase
, let’s write a simple Selenium
test. First of all, you need to install the selenium package into your
Python path:
pip install selenium
Then, add a LiveServerTestCase
-based test to your app’s tests module
(for example: myapp/tests.py
). The code for this test may look as follows:
from django.test import LiveServerTestCase
from selenium.webdriver.firefox.webdriver import WebDriver
class MySeleniumTests(LiveServerTestCase):
fixtures = ['user-data.json']
@classmethod
def setUpClass(cls):
cls.selenium = WebDriver()
super(MySeleniumTests, cls).setUpClass()
@classmethod
def tearDownClass(cls):
cls.selenium.quit()
super(MySeleniumTests, cls).tearDownClass()
def test_login(self):
self.selenium.get('%s%s' % (self.live_server_url, '/login/'))
username_input = self.selenium.find_element_by_name("username")
username_input.send_keys('myuser')
password_input = self.selenium.find_element_by_name("password")
password_input.send_keys('secret')
self.selenium.find_element_by_xpath('//input[@value="Log in"]').click()
Finally, you may run the test as follows:
./manage.py test myapp.MySeleniumTests.test_login
This example will automatically open Firefox then go to the login page, enter the credentials and press the “Log in” button. Selenium offers other drivers in case you do not have Firefox installed or wish to use another browser. The example above is just a tiny fraction of what the Selenium client can do; check out the full reference for more details.
Note
LiveServerTestCase
makes use of the staticfiles contrib app so you’ll need to have your project configured
accordingly (in particular by setting STATIC_URL
).
Note
When using an in-memory SQLite database to run the tests, the same database connection will be shared by two threads in parallel: the thread in which the live server is run and the thread in which the test case is run. It’s important to prevent simultaneous database queries via this shared connection by the two threads, as that may sometimes randomly cause the tests to fail. So you need to ensure that the two threads don’t access the database at the same time. In particular, this means that in some cases (for example, just after clicking a link or submitting a form), you might need to check that a response is received by Selenium and that the next page is loaded before proceeding with further test execution. Do this, for example, by making Selenium wait until the <body> HTML tag is found in the response (requires Selenium > 2.13):
def test_login(self):
from selenium.webdriver.support.wait import WebDriverWait
...
self.selenium.find_element_by_xpath('//input[@value="Log in"]').click()
# Wait until the response is received
WebDriverWait(self.selenium, timeout).until(
lambda driver: driver.find_element_by_tag_name('body'), timeout=10)
The tricky thing here is that there’s really no such thing as a “page load,” especially in modern Web apps that generate HTML dynamically after the server generates the initial document. So, simply checking for the presence of <body> in the response might not necessarily be appropriate for all use cases. Please refer to the Selenium FAQ and Selenium documentation for more information.
Clearly, doctest
and unittest
are not the only Python testing
frameworks. While Django doesn’t provide explicit support for alternative
frameworks, it does provide a way to invoke tests constructed for an
alternative framework as if they were normal Django tests.
When you run ./manage.py test
, Django looks at the TEST_RUNNER
setting to determine what to do. By default, TEST_RUNNER
points to
'django.test.simple.DjangoTestSuiteRunner'
. This class defines the default Django
testing behavior. This behavior involves:
models.py
and
tests.py
files in each installed application.syncdb
to install models and initial data into the test
databases.If you define your own test runner class and point TEST_RUNNER
at
that class, Django will execute your test runner whenever you run
./manage.py test
. In this way, it is possible to use any test framework
that can be executed from Python code, or to modify the Django test execution
process to satisfy whatever testing requirements you may have.
A test runner is a class defining a run_tests()
method. Django ships
with a DjangoTestSuiteRunner
class that defines the default Django
testing behavior. This class defines the run_tests()
entry point,
plus a selection of other methods that are used to by run_tests()
to
set up, execute and tear down the test suite.
DjangoTestSuiteRunner
(verbosity=1, interactive=True, failfast=True, **kwargs)¶verbosity
determines the amount of notification and debug information
that will be printed to the console; 0
is no output, 1
is normal
output, and 2
is verbose output.
If interactive
is True
, the test suite has permission to ask the
user for instructions when the test suite is executed. An example of this
behavior would be asking for permission to delete an existing test
database. If interactive
is False
, the test suite must be able to
run without any manual intervention.
If failfast
is True
, the test suite will stop running after the
first test failure is detected.
Django will, from time to time, extend the capabilities of
the test runner by adding new arguments. The **kwargs
declaration
allows for this expansion. If you subclass DjangoTestSuiteRunner
or
write your own test runner, ensure accept and handle the **kwargs
parameter.
Your test runner may also define additional command-line options.
If you add an option_list
attribute to a subclassed test runner,
those options will be added to the list of command-line options that
the test
command can use.
DjangoTestSuiteRunner.
option_list
¶This is the tuple of optparse
options which will be fed into the
management command’s OptionParser
for parsing arguments. See the
documentation for Python’s optparse
module for more details.
DjangoTestSuiteRunner.
run_tests
(test_labels, extra_tests=None, **kwargs)¶Run the test suite.
test_labels
is a list of strings describing the tests to be run. A test
label can take one of three forms:
app.TestCase.test_method
– Run a single test method in a test
case.app.TestCase
– Run all the test methods in a test case.app
– Search for and run all tests in the named application.If test_labels
has a value of None
, the test runner should run
search for tests in all the applications in INSTALLED_APPS
.
extra_tests
is a list of extra TestCase
instances to add to the
suite that is executed by the test runner. These extra tests are run
in addition to those discovered in the modules listed in test_labels
.
This method should return the number of tests that failed.
DjangoTestSuiteRunner.
setup_test_environment
(**kwargs)¶Sets up the test environment ready for testing.
DjangoTestSuiteRunner.
build_suite
(test_labels, extra_tests=None, **kwargs)¶Constructs a test suite that matches the test labels provided.
test_labels
is a list of strings describing the tests to be run. A test
label can take one of three forms:
app.TestCase.test_method
– Run a single test method in a test
case.app.TestCase
– Run all the test methods in a test case.app
– Search for and run all tests in the named application.If test_labels
has a value of None
, the test runner should run
search for tests in all the applications in INSTALLED_APPS
.
extra_tests
is a list of extra TestCase
instances to add to the
suite that is executed by the test runner. These extra tests are run
in addition to those discovered in the modules listed in test_labels
.
Returns a TestSuite
instance ready to be run.
DjangoTestSuiteRunner.
setup_databases
(**kwargs)¶Creates the test databases.
Returns a data structure that provides enough detail to undo the changes
that have been made. This data will be provided to the teardown_databases()
function at the conclusion of testing.
DjangoTestSuiteRunner.
run_suite
(suite, **kwargs)¶Runs the test suite.
Returns the result produced by the running the test suite.
DjangoTestSuiteRunner.
teardown_databases
(old_config, **kwargs)¶Destroys the test databases, restoring pre-test conditions.
old_config
is a data structure defining the changes in the
database configuration that need to be reversed. It is the return
value of the setup_databases()
method.
DjangoTestSuiteRunner.
teardown_test_environment
(**kwargs)¶Restores the pre-test environment.
DjangoTestSuiteRunner.
suite_result
(suite, result, **kwargs)¶Computes and returns a return code based on a test suite, and the result from that test suite.
To assist in the creation of your own test runner, Django provides a number of
utility methods in the django.test.utils
module.
setup_test_environment
()¶Performs any global pre-test setup, such as the installing the instrumentation of the template rendering system and setting up the dummy email outbox.
teardown_test_environment
()¶Performs any global post-test teardown, such as removing the black magic hooks into the template system and restoring normal email services.
The creation module of the database backend (connection.creation
)
also provides some utilities that can be useful during testing.
create_test_db
([verbosity=1, autoclobber=False])¶Creates a new test database and runs syncdb
against it.
verbosity
has the same behavior as in run_tests()
.
autoclobber
describes the behavior that will occur if a
database with the same name as the test database is discovered:
autoclobber
is False
, the user will be asked to
approve destroying the existing database. sys.exit
is
called if the user does not approve.True
, the database will be destroyed
without consulting the user.Returns the name of the test database that it created.
create_test_db()
has the side effect of modifying the value of
NAME
in DATABASES
to match the name of the test
database.
destroy_test_db
(old_database_name[, verbosity=1])¶Destroys the database whose name is the value of NAME
in
DATABASES
, and sets NAME
to the value of
old_database_name
.
The verbosity
argument has the same behavior as for
DjangoTestSuiteRunner
.
Nov 29, 2016