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
and retrieve
Web pages:
>>> from django.test import Client
>>> c = Client()
>>> response = c.post('/login/', {'username': 'john', 'password': 'smith'})
>>> response.status_code
200
>>> response = c.get('/customer/details/')
>>> response.content
b'<!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('https://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
.
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
class to make requests.
Client
(enforce_csrf_checks=False, **defaults)[source]¶It requires no arguments at time of construction. However, you can use
keywords arguments to specify some default headers. For example, this will
send a User-Agent
HTTP header in each request:
>>> c = Client(HTTP_USER_AGENT='Mozilla/5.0')
The values from the extra
keywords arguments passed to
get()
,
post()
, etc. have precedence over
the defaults passed to the class constructor.
The enforce_csrf_checks
argument can be used to test CSRF
protection (see above).
Once you have a Client
instance, you can call any of the following
methods:
get
(path, data=None, follow=False, secure=False, **extra)[source]¶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 a 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
[('http://testserver/next/', 302), ('http://testserver/final/', 302)]
If you set secure
to True
the client will emulate an HTTPS
request.
post
(path, data=None, content_type=MULTIPART_CONTENT, follow=False, secure=False, **extra)[source]¶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()
>>> with open('wishlist.doc') as fp:
... c.post('/customers/wishes/', {'name': 'fred', 'attachment': fp})
(The name attachment
here is not relevant; use whatever name your
file-processing code expects.)
You may also provide any file-like object (e.g., StringIO
or
BytesIO
) as a file handle.
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.
If you set secure
to True
the client will emulate an HTTPS
request.
head
(path, data=None, follow=False, secure=False, **extra)[source]¶Makes a HEAD request on the provided path
and returns a
Response
object. This method works just like Client.get()
,
including the follow
, secure
and extra
arguments, except
it does not return a message body.
options
(path, data=”, content_type=’application/octet-stream’, follow=False, secure=False, **extra)[source]¶Makes an OPTIONS request on the provided path
and returns a
Response
object. Useful for testing RESTful interfaces.
When data
is provided, it is used as the request body, and
a Content-Type
header is set to content_type
.
The follow
, secure
and extra
arguments act the same as for
Client.get()
.
put
(path, data=”, content_type=’application/octet-stream’, follow=False, secure=False, **extra)[source]¶Makes a PUT request on the provided path
and returns a
Response
object. Useful for testing RESTful interfaces.
When data
is provided, it is used as the request body, and
a Content-Type
header is set to content_type
.
The follow
, secure
and extra
arguments act the same as for
Client.get()
.
patch
(path, data=”, content_type=’application/octet-stream’, follow=False, secure=False, **extra)[source]¶Makes a PATCH request on the provided path
and returns a
Response
object. Useful for testing RESTful interfaces.
The follow
, secure
and extra
arguments act the same as for
Client.get()
.
delete
(path, data=”, content_type=’application/octet-stream’, follow=False, secure=False, **extra)[source]¶Makes a DELETE request on the provided path
and returns a
Response
object. Useful for testing RESTful interfaces.
When data
is provided, it is used as the request body, and
a Content-Type
header is set to content_type
.
The follow
, secure
and extra
arguments act the same as for
Client.get()
.
trace
(path, follow=False, secure=False, **extra)[source]¶Makes a TRACE request on the provided path
and returns a
Response
object. Useful for simulating diagnostic probes.
Unlike the other request methods, data
is not provided as a keyword
parameter in order to comply with RFC 7231#section-4.3.8, which
mandates that TRACE requests must not have a body.
The follow
, secure
, and extra
arguments act the same as for
Client.get()
.
login
(**credentials)[source]¶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.
In previous versions, inactive users (is_active=False
) were not permitted
to login.
force_login
(user, backend=None)[source]¶If your site uses Django’s authentication
system, you can use the force_login()
method
to simulate the effect of a user logging into the site. Use this method
instead of login()
when a test requires a user be logged in and
the details of how a user logged in aren’t important.
Unlike login()
, this method skips the authentication and
verification steps: inactive users (is_active=False
) are permitted to login
and the user’s credentials don’t need to be provided.
The user will have its backend
attribute set to the value of the
backend
argument (which should be a dotted Python path string), or
to settings.AUTHENTICATION_BACKENDS[0]
if a value isn’t provided.
The authenticate()
function called by
login()
normally annotates the user like this.
This method is faster than login()
since the expensive
password hashing algorithms are bypassed. Also, you can speed up
login()
by using a weaker hasher while testing.
logout
()[source]¶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
by 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 bytestring. 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'
Not using Django templates?
This attribute is only populated when using the
DjangoTemplates
backend.
If you’re using another template engine,
context_data
may be a suitable alternative on responses with that attribute.
json
(**kwargs)¶The body of the response, parsed as JSON. Extra keyword arguments are
passed to json.loads()
. For example:
>>> response = client.get('/foo/')
>>> response.json()['name']
'Arthur'
If the Content-Type
header is not "application/json"
, then a
ValueError
will be raised when trying to parse the response.
request
¶The request data that stimulated the response.
wsgi_request
¶The WSGIRequest
instance generated by the test handler that
generated the response.
status_code
¶The HTTP status of the response, as an integer. For a full list of defined codes, see the IANA status code registry.
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'
.)
Not using Django templates?
This attribute is only populated when using the
DjangoTemplates
backend.
If you’re using another template engine,
template_name
may be a suitable alternative if you only need the name of the
template used for rendering.
resolver_match
¶An instance of ResolverMatch
for the response.
You can use the func
attribute, for
example, to verify the view that served the response:
# my_view here is a function based view
self.assertEqual(response.resolver_match.func, my_view)
# class-based views need to be compared by name, as the functions
# generated by as_view() won't be equal
self.assertEqual(response.resolver_match.func.__name__, MyView.as_view().__name__)
If the given URL is not found, accessing this attribute will raise a
Resolver404
exception.
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
, SystemExit
, and
SuspiciousOperation
. 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
http.cookies
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()
When testing applications that support internationalization and localization,
you might want to set the language for a test client request. The method for
doing so depends on whether or not the
LocaleMiddleware
is enabled.
If the middleware is enabled, the language can be set by creating a cookie with
a name of LANGUAGE_COOKIE_NAME
and a value of the language code:
from django.conf import settings
def test_language_using_cookie(self):
self.client.cookies.load({settings.LANGUAGE_COOKIE_NAME: 'fr'})
response = self.client.get('/')
self.assertEqual(response.content, b"Bienvenue sur mon site.")
or by including the Accept-Language
HTTP header in the request:
def test_language_using_header(self):
response = self.client.get('/', HTTP_ACCEPT_LANGUAGE='fr')
self.assertEqual(response.content, b"Bienvenue sur mon site.")
More details are in How Django discovers language preference.
If the middleware isn’t enabled, the active language may be set using
translation.override()
:
from django.utils import translation
def test_language_using_override(self):
with translation.override('fr'):
response = self.client.get('/')
self.assertEqual(response.content, b"Bienvenue sur mon site.")
More details are in Explicitly setting the active language.
The following is a simple unit test using the test client:
import unittest
from django.test 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)
See also
Normal Python unit test classes extend a base class of
unittest.TestCase
. Django provides a few extensions of this base class:
Converting a normal unittest.TestCase
to any of the subclasses is
easy: change the base class of your test from unittest.TestCase
to the
subclass. All of the standard Python unit test functionality will be available,
and it will be augmented with some useful additions as described in each
section below.
SimpleTestCase
¶A subclass of unittest.TestCase
that adds this functionality:
raises a certain exception
.rendering and error treatment
.HTML responses for the presence/lack of a given fragment
.has/hasn't been used to generate a given
response content
.redirect
is
performed by the app.HTML fragments
for equality/inequality or containment
.XML fragments
for equality/inequality.JSON fragments
for equality.client
Client
.If your tests make any database queries, use subclasses
TransactionTestCase
or TestCase
.
SimpleTestCase.
allow_database_queries
¶SimpleTestCase
disallows database queries by default. This
helps to avoid executing write queries which will affect other tests
since each SimpleTestCase
test isn’t run in a transaction. If you
aren’t concerned about this problem, you can disable this behavior by
setting the allow_database_queries
class attribute to True
on
your test class.
Warning
SimpleTestCase
and its subclasses (e.g. TestCase
, …) rely on
setUpClass()
and tearDownClass()
to perform some class-wide
initialization (e.g. overriding settings). If you need to override those
methods, don’t forget to call the super
implementation:
class MyTestCase(TestCase):
@classmethod
def setUpClass(cls):
super(MyTestCase, cls).setUpClass()
...
@classmethod
def tearDownClass(cls):
...
super(MyTestCase, cls).tearDownClass()
Be sure to account for Python’s behavior if an exception is raised during
setUpClass()
. If that happens, neither the tests in the class nor
tearDownClass()
are run. In the case of django.test.TestCase
,
this will leak the transaction created in super()
which results in
various symptoms including a segmentation fault on some platforms (reported
on OS X). If you want to intentionally raise an exception such as
unittest.SkipTest
in setUpClass()
, be sure to do it before
calling super()
to avoid this.
TransactionTestCase
¶TransactionTestCase
inherits from SimpleTestCase
to
add some database-specific features:
fixtures
.assert*
methods.Django’s TestCase
class is a more commonly used subclass of
TransactionTestCase
that makes use of database transaction facilities
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 some database
behaviors cannot be tested within a Django TestCase
class. For instance,
you cannot test that a block of code is executing within a transaction, as is
required when using
select_for_update()
. In those cases,
you should use 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:
TransactionTestCase
resets the database after the test runs by
truncating all tables. A TransactionTestCase
may call commit and rollback
and observe the effects of these calls on the database.TestCase
, on the other hand, does not truncate tables after a test.
Instead, it encloses the test code in a database transaction that is rolled
back at the end of the test. This guarantees that the rollback at the end of
the test restores the database to its initial state.Warning
TestCase
running on a database that does not support rollback (e.g. MySQL
with the MyISAM storage engine), and all instances of TransactionTestCase
,
will roll back at the end of the test by deleting all data from the test
database.
Apps will not see their data reloaded;
if you need this functionality (for example, third-party apps should enable
this) you can set serialized_rollback = True
inside the
TestCase
body.
TestCase
¶This is the most common class to use for writing tests in Django. It inherits
from TransactionTestCase
(and by extension SimpleTestCase
).
If your Django application doesn’t use a database, use SimpleTestCase
.
The class:
atomic()
blocks: one for the whole class and one for each test. Therefore, if you want
to test some specific database transaction behavior, use
TransactionTestCase
.The check for deferrable database constraints at the end of each test was added.
It also provides an additional method:
TestCase.
setUpTestData
()[source]¶The class-level atomic
block described above allows the creation of
initial data at the class level, once for the whole TestCase
. This
technique allows for faster tests as compared to using setUp()
.
For example:
from django.test import TestCase
class MyTests(TestCase):
@classmethod
def setUpTestData(cls):
# Set up data for the whole TestCase
cls.foo = Foo.objects.create(bar="Test")
...
def test1(self):
# Some test using self.foo
...
def test2(self):
# Some other test using self.foo
...
Note that if the tests are run on a database with no transaction support
(for instance, MySQL with the MyISAM engine), setUpTestData()
will be
called before each test, negating the speed benefits.
Be careful not to modify any objects created in setUpTestData()
in
your test methods. Modifications to in-memory objects from setup work done
at the class level will persist between test methods. If you do need to
modify them, you could reload them in the setUp()
method with
refresh_from_db()
, for example.
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 listens on localhost
and picks the first
available port in the 8081-8179
range. Its full URL can be accessed with
self.live_server_url
during the tests.
In earlier versions, the live server’s default address was always
'localhost:8081'
.
If you’d like to select another address, you may pass a different one using the
test --liveserver
option, for example:
$ ./manage.py test --liveserver=localhost:8082
In older versions live_server_url
could only be accessed from an
instance. It now is a class property and can be accessed from class methods
like setUpClass()
.
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
). For this example, we’ll assume you’re using
the staticfiles
app and want to have static files served
during the execution of your tests similar to what we get at development time
with DEBUG=True
, i.e. without having to collect them using
collectstatic
. We’ll use
the StaticLiveServerTestCase
subclass which provides that functionality. Replace it with
django.test.LiveServerTestCase
if you don’t need that.
The code for this test may look as follows:
from django.contrib.staticfiles.testing import StaticLiveServerTestCase
from selenium.webdriver.firefox.webdriver import WebDriver
class MySeleniumTests(StaticLiveServerTestCase):
fixtures = ['user-data.json']
@classmethod
def setUpClass(cls):
super(MySeleniumTests, cls).setUpClass()
cls.selenium = WebDriver()
cls.selenium.implicitly_wait(10)
@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.tests.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
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
timeout = 2
...
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'))
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.
SimpleTestCase.
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:
import unittest
from django.test 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)
SimpleTestCase.
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, 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...
call_some_test_code()
TransactionTestCase.
fixtures
¶A test case for a database-backed website isn’t much use if there isn’t any
data in the database. Tests are more readable and it’s more maintainable to
create objects using the ORM, for example in TestCase.setUpTestData()
,
however, you can also use 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.
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
migrate
was called.mammals
, followed by any fixture named
birds
. See the loaddata
documentation for more
details on defining and installing fixtures.For performance reasons, TestCase
loads fixtures once for the entire
test class, before setUpTestData()
, instead of before each
test, and it uses transactions to clean the database before each test. In any case,
you can be certain that the outcome of a test will not be affected by another
test or by the order of test execution.
By default, fixtures are only loaded into the default
database. If you are
using multiple databases and set multi_db=True
, fixtures will be loaded into all databases.
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. Decorate your test class or test method with
@override_settings(ROOT_URLCONF=...)
for URLconf configuration.
TransactionTestCase.
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 test_index_page_view(self):
call_some_test_code()
This test case will flush all the test databases before running
test_index_page_view
.
The multi_db
flag also affects into which databases the
TransactionTestCase.fixtures
are loaded. By default (when
multi_db=False
), fixtures are only loaded into the default
database.
If multi_db=True
, fixtures are loaded into all databases.
Warning
Use the functions below to temporarily alter the value of settings in tests.
Don’t manipulate django.conf.settings
directly as Django won’t restore
the original values after such manipulations.
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) called
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.
It can prove unwieldy to redefine settings that contain a list of values. In
practice, adding or removing values is often sufficient. The
modify_settings()
context manager makes it
easy:
from django.test import TestCase
class MiddlewareTestCase(TestCase):
def test_cache_middleware(self):
with self.modify_settings(MIDDLEWARE={
'append': 'django.middleware.cache.FetchFromCacheMiddleware',
'prepend': 'django.middleware.cache.UpdateCacheMiddleware',
'remove': [
'django.contrib.sessions.middleware.SessionMiddleware',
'django.contrib.auth.middleware.AuthenticationMiddleware',
'django.contrib.messages.middleware.MessageMiddleware',
],
}):
response = self.client.get('/')
# ...
For each action, you can supply either a list of values or a string. When the
value already exists in the list, append
and prepend
have no effect;
neither does remove
when the value doesn’t exist.
In case you want to override a setting for a test method, Django provides the
override_settings()
decorator (see PEP 318). It’s used
like this:
from django.test import TestCase, 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 TestCase
classes:
from django.test import TestCase, 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/')
Likewise, Django provides the modify_settings()
decorator:
from django.test import TestCase, modify_settings
class MiddlewareTestCase(TestCase):
@modify_settings(MIDDLEWARE={
'append': 'django.middleware.cache.FetchFromCacheMiddleware',
'prepend': 'django.middleware.cache.UpdateCacheMiddleware',
})
def test_cache_middleware(self):
response = self.client.get('/')
# ...
The decorator can also be applied to test case classes:
from django.test import TestCase, modify_settings
@modify_settings(MIDDLEWARE={
'append': 'django.middleware.cache.FetchFromCacheMiddleware',
'prepend': 'django.middleware.cache.UpdateCacheMiddleware',
})
class MiddlewareTestCase(TestCase):
def test_cache_middleware(self):
response = self.client.get('/')
# ...
Note
When given a class, these decorators modify the class directly and return
it; they don’t create and return a modified copy of it. So if you try to
tweak the above examples to assign the return value to a different name
than LoginTestCase
or MiddlewareTestCase
, you may be surprised to
find that the original test case classes are still equally affected by the
decorator. For a given class, modify_settings()
is
always applied after override_settings()
.
Warning
The settings file contains some settings that are only consulted during
initialization of Django internals. If you change them with
override_settings
, the setting is changed if you access it via the
django.conf.settings
module, however, Django’s internals access it
differently. Effectively, using override_settings()
or
modify_settings()
with these settings is probably not
going to do what you expect it to do.
We do not recommend altering the DATABASES
setting. Altering
the CACHES
setting is possible, but a bit tricky if you are
using internals that make using of caching, like
django.contrib.sessions
. For example, you will have to reinitialize
the session backend in a test that uses cached sessions and overrides
CACHES
.
Finally, avoid aliasing your settings as module-level constants as
override_settings()
won’t work on such values since they are
only evaluated the first time the module is imported.
You can also simulate the absence of a setting by deleting it after settings have been overridden, like this:
@override_settings()
def test_something(self):
del settings.LOGIN_URL
...
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.
Django itself uses this signal to reset various data:
Overridden settings | Data reset |
---|---|
USE_TZ, TIME_ZONE | Databases timezone |
TEMPLATES | Template engines |
SERIALIZATION_MODULES | Serializers cache |
LOCALE_PATHS, LANGUAGE_CODE | Default translation and loaded translations |
MEDIA_ROOT, DEFAULT_FILE_STORAGE | Default file storage |
If you use any of Django’s custom TestCase
classes, 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 below.
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 a failure in
your test suite.
SimpleTestCase.
assertRaisesMessage
(expected_exception, expected_message, callable, *args, **kwargs)[source]¶SimpleTestCase.
assertRaisesMessage
(expected_exception, expected_message)Asserts that execution of callable
raises expected_exception
and
that expected_message
is found in the exception’s message. Any other
outcome is reported as a failure. It’s a simpler version of
unittest.TestCase.assertRaisesRegex()
with the difference that
expected_message
isn’t treated as a regular expression.
If only the expected_exception
and expected_message
parameters are
given, returns a context manager so that the code being tested can be
written inline rather than as a function:
with self.assertRaisesMessage(ValueError, 'invalid literal for int()'):
int('a')
Deprecated since version 1.9: Passing callable
as a keyword argument called callable_obj
is
deprecated. Pass the callable as a positional argument instead.
SimpleTestCase.
assertFieldOutput
(fieldclass, valid, invalid, field_args=None, field_kwargs=None, empty_value=”)[source]¶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, {'[email protected]': '[email protected]'}, {'aaa': ['Enter a valid email address.']})
SimpleTestCase.
assertFormError
(response, form, field, errors, msg_prefix=”)[source]¶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.
SimpleTestCase.
assertFormsetError
(response, formset, form_index, field, errors, msg_prefix=”)[source]¶Asserts that the formset
raises the provided list of errors when
rendered.
formset
is the name the Formset
instance was given in the template
context.
form_index
is the number of the form within the Formset
. If
form_index
has a value of None
, non-form errors (errors you can
access via formset.non_form_errors()
) will be checked.
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.
SimpleTestCase.
assertContains
(response, text, count=None, status_code=200, msg_prefix=”, html=False)[source]¶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.
SimpleTestCase.
assertNotContains
(response, text, status_code=200, msg_prefix=”, html=False)[source]¶Asserts that a Response
instance produced the given status_code
and
that text
does not appear 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.
SimpleTestCase.
assertTemplateUsed
(response, template_name, msg_prefix=”, count=None)[source]¶Asserts that the template with the given name was used in rendering the response.
The name is a string such as 'admin/index.html'
.
The count argument is an integer indicating the number of times the
template should be rendered. Default is None
, meaning that the template
should be rendered one or more times.
You can use this as a context manager, like this:
with self.assertTemplateUsed('index.html'):
render_to_string('index.html')
with self.assertTemplateUsed(template_name='index.html'):
render_to_string('index.html')
SimpleTestCase.
assertTemplateNotUsed
(response, template_name, msg_prefix=”)[source]¶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()
.
SimpleTestCase.
assertRedirects
(response, expected_url, status_code=302, target_status_code=200, msg_prefix=”, fetch_redirect_response=True)[source]¶Asserts that the response returned a status_code
redirect status,
redirected to expected_url
(including any GET
data), and that 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.
If fetch_redirect_response
is False
, the final page won’t be
loaded. Since the test client can’t fetch external URLs, this is
particularly useful if expected_url
isn’t part of your Django app.
Scheme is handled correctly when making comparisons between two URLs. If
there isn’t any scheme specified in the location where we are redirected to,
the original request’s scheme is used. If present, the scheme in
expected_url
is the one used to make the comparisons to.
Deprecated since version 1.9: The host
argument is deprecated, as redirections are no longer
forced to be absolute URLs.
SimpleTestCase.
assertHTMLEqual
(html1, html2, msg=None)[source]¶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.
Output in case of error can be customized with the msg
argument.
SimpleTestCase.
assertHTMLNotEqual
(html1, html2, msg=None)[source]¶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.
Output in case of error can be customized with the msg
argument.
SimpleTestCase.
assertXMLEqual
(xml1, xml2, msg=None)[source]¶Asserts that the strings xml1
and xml2
are equal. The
comparison is based on XML semantics. Similarly to
assertHTMLEqual()
, the comparison is
made on parsed content, hence only semantic differences are considered, not
syntax differences. When invalid XML is passed in any parameter, an
AssertionError
is always raised, even if both string are identical.
Output in case of error can be customized with the msg
argument.
SimpleTestCase.
assertXMLNotEqual
(xml1, xml2, msg=None)[source]¶Asserts that the strings xml1
and xml2
are not equal. The
comparison is based on XML semantics. See
assertXMLEqual()
for details.
Output in case of error can be customized with the msg
argument.
SimpleTestCase.
assertInHTML
(needle, haystack, count=None, msg_prefix=”)[source]¶Asserts that the HTML fragment needle
is contained in the haystack
one.
If the count
integer argument is specified, then additionally the number
of needle
occurrences will be strictly verified.
Whitespace in most cases is ignored, and attribute ordering is not significant. The passed-in arguments must be valid HTML.
SimpleTestCase.
assertJSONEqual
(raw, expected_data, msg=None)[source]¶Asserts that the JSON fragments raw
and expected_data
are equal.
Usual JSON non-significant whitespace rules apply as the heavyweight is
delegated to the json
library.
Output in case of error can be customized with the msg
argument.
SimpleTestCase.
assertJSONNotEqual
(raw, expected_data, msg=None)[source]¶Asserts that the JSON fragments raw
and expected_data
are not equal.
See assertJSONEqual()
for further details.
Output in case of error can be customized with the msg
argument.
TransactionTestCase.
assertQuerysetEqual
(qs, values, transform=repr, ordered=True, msg=None)[source]¶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 collections.Counter
comparison.
If the order is undefined (if the given qs
isn’t ordered and the
comparison is against more than one ordered values), a ValueError
is
raised.
Output in case of error can be customized with the msg
argument.
TransactionTestCase.
assertNumQueries
(num, func, *args, **kwargs)[source]¶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))
You can also use this as a context manager:
with self.assertNumQueries(2):
Person.objects.create(name="Aaron")
Person.objects.create(name="Daniel")
You can tag your tests so you can easily run a particular subset. For example, you might label fast or slow tests:
from django.test import tag
class SampleTestCase(TestCase):
@tag('fast')
def test_fast(self):
...
@tag('slow')
def test_slow(self):
...
@tag('slow', 'core')
def test_slow_but_core(self):
...
You can also tag a test case:
@tag('slow', 'core')
class SampleTestCase(TestCase):
...
Then you can choose which tests to run. For example, to run only fast tests:
$ ./manage.py test --tag=fast
Or to run fast tests and the core one (even though it’s slow):
$ ./manage.py test --tag=fast --tag=core
You can also exclude tests by tag. To run core tests if they are not slow:
$ ./manage.py test --tag=core --exclude-tag=slow
test --exclude-tag
has precedence over test --tag
, so if a
test has two tags and you select one of them and exclude the other, the test
won’t be run.
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.',
'[email protected]', ['[email protected]'],
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 = []
Management commands can be tested with the
call_command()
function. The output can be
redirected into a StringIO
instance:
from django.core.management import call_command
from django.test import TestCase
from django.utils.six import StringIO
class ClosepollTest(TestCase):
def test_command_output(self):
out = StringIO()
call_command('closepoll', stdout=out)
self.assertIn('Expected output', out.getvalue())
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 django.db.backends.BaseDatabaseFeatures
class for a full list of database features that can be used as a basis
for skipping tests.
Skip the decorated test or TestCase
if all of the named database features
are 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
pass
Skip the decorated test or TestCase
if any of the named database features
are 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
pass
Jun 09, 2017