I am using multiple fixtures inside a use fixture decorator as below:
#pytest.mark.usefixtures(fixture1, fixture2)
def test_me:
Fixtures file:
#pytest.fixture
def fixture1:
#pytest.fixture
def fixture2:
The problem is that I need these two fixtures to be triggered at a specific line in my code snippet, but these two fixtures triggers simultaneously.
How can this be achieved?
The fixtures are not triggers simultaneously, but both are triggered before the test when you use them as arguments, which is the expected behavior. You can also see it in the error message if you try to call the fixture from the test
def test_me():
fixture1()
Fixture "fixture1" called directly. Fixtures are not meant to be
called directly, but are created automatically when test functions
request them as parameters.
If all your tests require the fixtures in test run time don't use regular functions and not fixtures. If this usecase is unique you can add another function that can be called from the fixture and from the tests
def fixture1_implementation():
...
#pytest.fixture
def fixture1():
fixture1_implementation()
def test_me():
fixture1_implementation()
# or
#pytest.mark.usefixtures('fixture1')
def test_example():
...
Related
So, I have fixtures defined in conftest.py file with scope="class" as I want to run them before each test class is invoked. The conftest file is placed inside project root directory for it to be visible to every test module.
Now in one of the test modules, I have another setup function which I want to run once for that module only. But the problem is setup_class() method is called before running fixtures defined in conftest.py. Is this expected? I wanted it to be opposite because I want to use something done in the fixtures defined in conftest. How to do that?
Code -
conftest.py:
#pytest.fixture(scope="class")
def fixture1(request):
#set a
#pytest.fixture(scope="class")
def fixture1(request):
test_1.py:
#pytest.mark.usefixtures("fixture_1", "fixture_2")
class Test1():
#need this to run AFTER the fixture_1 & fixture_2
def setup_class():
#setup
#get a set in fixture_1
def test_1()
.....
I know that I could simply define a fixture in the test file instead of setup_class but then I will have to specify it in arguments of every test method in order it to be invoked by pytest. But suggestions are welcome!
I have exactly the same problem. Only now I have realized that the problem might be taht the setup_class is called before the fixture >-/
I think that this question is similar to this one
Pytest - How to pass an argument to setup_class?
And the problem is mixing the unittest and pytest methods.
I kind of did what they suggested - I ommitted the setup_class and created a new fixture within the particular test file,
calling the fixture in the conftest.py.
It works so far.
M.
The problem is that you can use the result of a fixture only in test function (or method) which is run by pytest. Here I can suggest a workaround. But of course I'm not sure if it suites your needs.
The workaround is to call the function from a test method:
conftest.py
#pytest.fixture(scope='class')
def fixture1():
yield 'MYTEXT'
test_1.py
class Test1:
def setup_class(self, some_var):
print(some_var)
def test_one(self, fixture1):
self.setup_class(fixture1)
Fixtures and setup_class are two different paradigms to initialize test functions (and classes). In this case, mixing the two creates a problem: The class-scoped fixtures run when the individual test functions (methods) run. On the other hand, setup_class runs before they do. Hence, it is not possible to access a fixture value (or fixture-modified state) from setup_class.
One of the solutions is to stop using setup_class entirely and stick with a fixtures-only solution which is the preferred way in pytest nowadays (see the note at the beginning).
# conftest.py or the test file:
#pytest.fixture(scope="class")
def fixture_1(request):
print('fixture_1')
# the test file:
class Test1():
#pytest.fixture(scope="class", autouse=True)
def setup(self, fixture_1, request):
print('Test1.setup')
def test_a(self):
print('Test1.test_a')
def test_b(self):
print('Test1.test_b')
Note that the setup fixture depends on fixture_1 and hence can access it.
In my current setup of end-to-end tests I am using Selenium. I have a fixture that looks something like this:
#pytest.fixture(scope="session")
def browser(request):
# Here I do a basic setup
# Setting up accounts from configuration based on input from test function
# Initializing webdriver wrapper with this data
# yield driver
# teardown
So far I was only using parameters for a fixture and typical test function would look like this:
#pytest.mark.parametrize('browser', [(SomeEnum, AnotherEnum1),
(SomeEnum, AnotherEnum2)], indirect=True)
def some_test(browser):
This will result in two tests:
some_test[broswer0]
some_test[browser1]
I am trying to combine parameters for a function and parameters for a fixture now, so test function looks like this:
#pytest.mark.parametrize('browser', [([SomeEnum1, SomeEnum2], AnotherEnum)], indirect=True)
#pytest.mark.parametrize('param1,param2', [(DifferentEnum, False), (DifferentEnum2, True)])
def some_test(browser, param1, param2):
This setup will result in 2 tests, which I want:
some_test[DifferentEnum-False-browser0]
some_test[DifferentEnum2-True-browser0]
If I run tests individually, everything is fine. But if I run them together, first one will finish and pass and it seems that second one doesn't go through the fixture at all, but browser session just stays open.
What I need to change for fixture to be executed for each of the tests?
Narrow the scope of the browser fixture:
#pytest.fixture(scope="function")
def browser(request):
...
or just drop it completely since function is the default scope.
#pytest.fixture
def browser(request):
...
I'm trying to create a test environment with Pytest. The idea is to group test methods into classes.
For every class/group, I want to attach a config fixture that is going to be parametrized. So that I can run all the tests with "configuration A" and then all tests with "configuration B" and so on.
But also, I want a reset fixture, that can be executed before specific methods or all methods of a class.
The problem I have there is, once I apply my reset fixture (to a method or to a whole class), the config fixture seems to work in the function scope instead of the class scope. So, once I apply the reset fixture, the config fixture is called before/after every method in the class.
The following piece of code reproduces the problem:
import pytest
from pytest import *
#fixture(scope='class')
def config(request):
print("\nconfiguring with %s" % request.param)
yield
print("\ncleaning up config")
#fixture(scope='function')
def reset():
print("\nreseting")
#mark.parametrize("config", ["config-A", "config-B"], indirect=True)
##mark.usefixtures("reset")
class TestMoreStuff(object):
def test_a(self, config):
pass
def test_b(self, config):
pass
def test_c(self, config):
pass
The test shows how the config fixture should work, being executed only once for the whole class. If you uncomment the usefixtures decoration, you can notice that the config fixture will be executed in every test method. Is it possible to use the reset fixture without triggering this behaviour?
As I mentioned in a comment, that seems to be a bug in Pytest 3.2.5.
There's a workaround, which is to "force" the scope of a parametrization. So, in this case if you include the scope="class" in the parametrize decorator, you get the desired behaviour.
import pytest
from pytest import *
#fixture(scope='class')
def config(request):
print("\nconfiguring with %s" % request.param)
yield
print("\ncleaning up config")
#fixture(scope='function')
def reset():
print("\nreseting")
#mark.parametrize("config", ["config-A", "config-B"], indirect=True, scope="class")
#mark.usefixtures("reset")
class TestMoreStuff(object):
def test_a(self, config):
pass
def test_b(self, config):
pass
def test_c(self, config):
pass
It depends on which version of pytest you are using.
There are some semantical problems to implement this in older versions of pytest. So, this idea is not yet implemented in older pytest. Someone has already given suggestion to implement the same. you can refer this
"Fixture scope doesn't work when parametrized tests use parametrized fixtures".
This was the bug.
You can refer this
This issue has been resolved in latest version of pytest. Here's the commit for the same with pytest 3.2.5
Hope it would help you.
I am having difficulty using fixtures with my pytest unit tests.
I am using a test class like this:
class TestMyApp(object):
def setup(self):
self.client = mock_client()
#pytest.fixture
def client_item(self):
return self.client.create_item('test_item')
def test_something1(self, client_item):
# Test here.
pass
When I run the above test I get the following exception:
AttributeError: 'TestMyApp' object has no attribute 'client'
I believe this is because the client_item() fixture function is being called before the setup() function.
Am I using fixtures incorrectly? Or is there some way I can force setup() to be called before the fixture functions?
Thanks in advance.
Fixtures can use other fixtures, so you can use fixtures all the way down:
class TestMyApp(object):
#pytest.fixture
def client(self):
return mock_client()
#pytest.fixture
def client_item(self, client):
return client.create_item('test_item')
def test_something1(self, client_item):
# Test here.
pass
The documentation subtly recommends fixtures over xUnit style setup/teardown methods:
While these setup/teardown methods are simple and familiar to those coming from a unittest or nose background, you may also consider using pytest’s more powerful fixture mechanism which leverages the concept of dependency injection, allowing for a more modular and more scalable approach for managing test state, especially for larger projects and for functional testing.
It goes on to say that the two styles can be mixed, but isn't clear about the order in which things will happen.
I want to run additional setup and teardown checks before and after each test in my test suite. I've looked at fixtures but not sure on whether they are the correct approach. I need to run the setup code prior to each test and I need to run the teardown checks after each test.
My use-case is checking for code that doesn't cleanup correctly: it leaves temporary files. In my setup, I will check the files and in the teardown I also check the files. If there are extra files I want the test to fail.
py.test fixtures are a technically adequate method to achieve your purpose.
You just need to define a fixture like that:
#pytest.fixture(autouse=True)
def run_around_tests():
# Code that will run before your test, for example:
files_before = # ... do something to check the existing files
# A test function will be run at this point
yield
# Code that will run after your test, for example:
files_after = # ... do something to check the existing files
assert files_before == files_after
By declaring your fixture with autouse=True, it will be automatically invoked for each test function defined in the same module.
That said, there is one caveat. Asserting at setup/teardown is a controversial practice. I'm under the impression that the py.test main authors do not like it (I do not like it either, so that may colour my own perception), so you might run into some problems or rough edges as you go forward.
You can use a fixture in order to achieve what you want.
import pytest
#pytest.fixture(autouse=True)
def run_before_and_after_tests(tmpdir):
"""Fixture to execute asserts before and after a test is run"""
# Setup: fill with any logic you want
yield # this is where the testing happens
# Teardown : fill with any logic you want
Detailed Explanation
#pytest.fixture(autouse=True), from the docs: "Occasionally, you may want to have fixtures get invoked automatically without declaring a function argument explicitly or a usefixtures decorator." Therefore, this fixture will run every time a test is executed.
# Setup: fill with any logic you want, this logic will be executed before every test is actually run. In your case, you can add your assert statements that will be executed before the actual test.
yield, as indicated in the comment, this is where testing happens
# Teardown : fill with any logic you want, this logic will be executed after every test. This logic is guaranteed to run regardless of what happens during the
tests.
Note: in pytest there is a difference between a failing test and an error while executing a test. A Failure indicates that the test failed in some way.
An Error indicates that you couldn't get to the point of doing a proper test.
Consider the following examples:
Assert fails before test is run -> ERROR
import pytest
#pytest.fixture(autouse=True)
def run_around_tests():
assert False # This will generate an error when running tests
yield
assert True
def test():
assert True
Assert fails after test is run -> ERROR
import pytest
#pytest.fixture(autouse=True)
def run_around_tests():
assert True
yield
assert False
def test():
assert True
Test fails -> FAILED
import pytest
#pytest.fixture(autouse=True)
def run_around_tests():
assert True
yield
assert True
def test():
assert False
Test passes -> PASSED
import pytest
#pytest.fixture(autouse=True)
def run_around_tests():
assert True
yield
assert True
def test():
assert True
Fixtures are exactly what you want.
That's what they are designed for.
Whether you use pytest style fixtures, or setup and teardown (module, class, or method level) xUnit style fixtures, depends on the circumstance and personal taste.
From what you are describing, it seems like you could use pytest autouse fixtures.
Or xUnit style function level setup_function()/teardown_function().
Pytest has you completely covered. So much so that perhaps it's a fire hose of information.
You can use Module level setup/teardown Fixtures of Pytest.
Here's the Link
http://pytest.org/latest/xunit_setup.html
It Works as follows:
def setup_module(module):
""" setup any state specific to the execution of the given module."""
def teardown_module(module):
""" teardown any state that was previously setup with a setup_module
method."""
Test_Class():
def test_01():
#test 1 Code
It will call setup_module before this test and teardown_module after test completes.
You can include this fixture in each test-script to run it for each test.
IF you want to use something that is common to all tests in a directory You can use package/directory level fixtures nose framework
http://pythontesting.net/framework/nose/nose-fixture-reference/#package
In __init__.py file of the package you can include following
def setup_package():
'''Set up your environment for test package'''
def teardown_package():
'''revert the state '''
You may use decorators but programatically, so you don't need to put the decorator in each method.
I'm assuming several things in next code:
The test methods are all named like: "testXXX()"
The decorator is added to the same module where test methods are implemented.
def test1():
print ("Testing hello world")
def test2():
print ("Testing hello world 2")
#This is the decorator
class TestChecker(object):
def __init__(self, testfn, *args, **kwargs):
self.testfn = testfn
def pretest(self):
print ('precheck %s' % str(self.testfn))
def posttest(self):
print ('postcheck %s' % str(self.testfn))
def __call__(self):
self.pretest()
self.testfn()
self.posttest()
for fn in dir() :
if fn.startswith('test'):
locals()[fn] = TestChecker(locals()[fn])
Now if you call the test methods...
test1()
test2()
The output should be something like:
precheck <function test1 at 0x10078cc20>
Testing hello world
postcheck <function test1 at 0x10078cc20>
precheck <function test2 at 0x10078ccb0>
Testing hello world 2
postcheck <function test2 at 0x10078ccb0>
If you have test methods as class methods, the approach is also valid. For instance:
class TestClass(object):
#classmethod
def my_test(cls):
print ("Testing from class method")
for fn in dir(TestClass) :
if not fn.startswith('__'):
setattr(TestClass, fn, TestChecker(getattr(TestClass, fn)))
The call to TestClass.my_test() will print:
precheck <bound method type.my_test of <class '__main__.TestClass'>>
Testing from class method
postcheck <bound method type.my_test of <class '__main__.TestClass'>>
It is an old question but I personally found another way from the docs :
Use the pytest.ini file :
[pytest]
usefixtures = my_setup_and_tear_down
import pytest
#pytest.fixture
def my_setup_and_tear_down():
# SETUP
# Write here the logic that you need for the setUp
yield # this statement will let the tests execute
# TEARDOWN
# Write here the logic that you need after each tests
About the yield statement and how it allows to run the test : HERE
Fixtures by default have scope=function. So, if you just use a definition such as
#pytest.fixture
def fixture_func(self)
It defaults to (scope='function').
So any finalizers in the fixture function will be called after each test.