I have 92 tests and I want to make sure that no silent errors occurred during the calls.
Unfortunately error handing in OpenGL is not quite good. I want to test if glGetError() returns other then GL_NO_ERROR It is enough if I test it once per TestCase. It would be better if I could add an assert after every test methods. (I don't want to add it manually in 92 methods)
I made an example snippet that shows a solution that is not acceptable since the assert is done in the tearDownClass(cls) method and tearDownClass should not do any testing logic.
How can I add an extra assert after my tests?
The lines with comments show what I wan't to achieve.
import struct
import unittest
import ModernGL
class TestCase(unittest.TestCase):
#classmethod
def setUpClass(cls):
cls.ctx = ModernGL.create_standalone_context()
#classmethod
def tearDownClass(cls):
error = cls.ctx.error # Store error in a variable
cls.ctx.release() # Then release the context
cls.assertEqual(error, 'GL_NO_ERROR') # Check if there were errors before the release
def test_1(self):
...
def test_2(self):
...
def test_3(self):
...
if __name__ == '__main__':
unittest.main()
NOTE:
cls.ctx.error is a property (glGetError() as a string) and the possible values are:
"GL_NO_ERROR"
"GL_INVALID_ENUM"
"GL_INVALID_VALUE"
"GL_INVALID_OPERATION"
"GL_INVALID_FRAMEBUFFER_OPERATION"
"GL_OUT_OF_MEMORY"
"GL_STACK_UNDERFLOW"
"GL_STACK_OVERFLOW"
"GL_UNKNOWN_ERROR"
You could do the test in the tearDown (as opposed to tearDownClass) method, as this is a regular instance method:
class TestCase(unittest.TestCase):
def setUp(self):
self.ctx = ModernGL.create_standalone_context()
def tearDown(self):
error = self.ctx.error # Store error in a variable
self.ctx.release() # Then release the context
self.assertEqual(error, 'GL_NO_ERROR') # Check if there were errors before the release
I am using selenium for end to end testing and I can't get how to use setup_class and teardown_class methods.
I need to set up browser in setup_class method, then perform a bunch of tests defined as class methods and finally quit browser in teardown_class method.
But logically it seems like a bad solution, because in fact my tests will not work with class, but with object. I pass self param inside every test method, so I can access objects' vars:
class TestClass:
def setup_class(cls):
pass
def test_buttons(self, data):
# self.$attribute can be used, but not cls.$attribute?
pass
def test_buttons2(self, data):
# self.$attribute can be used, but not cls.$attribute?
pass
def teardown_class(cls):
pass
And it even seems not to be correct to create browser instance for class.. It should be created for every object separately, right?
So, I need to use __init__ and __del__ methods instead of setup_class and teardown_class?
According to Fixture finalization / executing teardown code, the current best practice for setup and teardown is to use yield instead of return:
import pytest
#pytest.fixture()
def resource():
print("setup")
yield "resource"
print("teardown")
class TestResource:
def test_that_depends_on_resource(self, resource):
print("testing {}".format(resource))
Running it results in
$ py.test --capture=no pytest_yield.py
=== test session starts ===
platform darwin -- Python 2.7.10, pytest-3.0.2, py-1.4.31, pluggy-0.3.1
collected 1 items
pytest_yield.py setup
testing resource
.teardown
=== 1 passed in 0.01 seconds ===
Another way to write teardown code is by accepting a request-context object into your fixture function and calling its request.addfinalizer method with a function that performs the teardown one or multiple times:
import pytest
#pytest.fixture()
def resource(request):
print("setup")
def teardown():
print("teardown")
request.addfinalizer(teardown)
return "resource"
class TestResource:
def test_that_depends_on_resource(self, resource):
print("testing {}".format(resource))
When you write "tests defined as class methods", do you really mean class methods (methods which receive its class as first parameter) or just regular methods (methods which receive an instance as first parameter)?
Since your example uses self for the test methods I'm assuming the latter, so you just need to use setup_method instead:
class Test:
def setup_method(self, test_method):
# configure self.attribute
def teardown_method(self, test_method):
# tear down self.attribute
def test_buttons(self):
# use self.attribute for test
The test method instance is passed to setup_method and teardown_method, but can be ignored if your setup/teardown code doesn't need to know the testing context. More information can be found here.
I also recommend that you familiarize yourself with py.test's fixtures, as they are a more powerful concept.
This might help http://docs.pytest.org/en/latest/xunit_setup.html
In my test suite, I group my test cases into classes. For the setup and teardown I need for all the test cases in that class, I use the setup_class(cls) and teardown_class(cls) classmethods.
And for the setup and teardown I need for each of the test case, I use the setup_method(method) and teardown_method(methods)
Example:
lh = <got log handler from logger module>
class TestClass:
#classmethod
def setup_class(cls):
lh.info("starting class: {} execution".format(cls.__name__))
#classmethod
def teardown_class(cls):
lh.info("starting class: {} execution".format(cls.__name__))
def setup_method(self, method):
lh.info("starting execution of tc: {}".format(method.__name__))
def teardown_method(self, method):
lh.info("starting execution of tc: {}".format(method.__name__))
def test_tc1(self):
<tc_content>
assert
def test_tc2(self):
<tc_content>
assert
Now when I run my tests, when the TestClass execution is starting, it logs the details for when it is beginning execution, when it is ending execution and same for the methods..
You can add up other setup and teardown steps you might have in the respective locations.
Hope it helps!
As #Bruno suggested, using pytest fixtures is another solution that is accessible for both test classes or even just simple test functions. Here's an example testing python2.7 functions:
import pytest
#pytest.fixture(scope='function')
def some_resource(request):
stuff_i_setup = ["I setup"]
def some_teardown():
stuff_i_setup[0] += " ... but now I'm torn down..."
print stuff_i_setup[0]
request.addfinalizer(some_teardown)
return stuff_i_setup[0]
def test_1_that_needs_resource(some_resource):
print some_resource + "... and now I'm testing things..."
So, running test_1... produces:
I setup... and now I'm testing things...
I setup ... but now I'm torn down...
Notice that stuff_i_setup is referenced in the fixture, allowing that object to be setup and torn down for the test it's interacting with. You can imagine this could be useful for a persistent object, such as a hypothetical database or some connection, that must be cleared before each test runs to keep them isolated.
Your code should work just as you expect it to if you add #classmethod decorators.
#classmethod
def setup_class(cls):
"Runs once per class"
#classmethod
def teardown_class(cls):
"Runs at end of class"
See http://pythontesting.net/framework/pytest/pytest-xunit-style-fixtures/
import pytest
class Test:
#pytest.fixture()
def setUp(self):
print("setup")
yield "resource"
print("teardown")
def test_that_depends_on_resource(self, setUp):
print("testing {}".format(setUp))
In order to run:
pytest nam_of_the_module.py -v
I'm not sure I got the specifics of using Selenium in your original questions, but in case you were simply asking about how to use a more classical setUp/tearDown style, Pytest supports most unittest features, so you could do something like:
import unittest
class TestHello(unittest.TestCase):
def setUp(self):
print('running setUp')
def test_one(self):
print('running test_one')
def test_two(self):
print('running test_two')
def tearDown(self):
print('running tearDown')
Which produces:
$ pytest -s -v
====================== test session starts =======================
platform linux -- Python 3.8.2, pytest-6.2.4, py-1.10.0, pluggy-0.13.1 -- /gnu/store/nckjv3ccwdi6096j478gvns43ssbls2p-python-wrapper-3.8.2/bin/python
cachedir: .pytest_cache
hypothesis profile 'default' -> database=DirectoryBasedExampleDatabase('/tmp/test/.hypothesis/examples')
rootdir: /tmp/test
plugins: hypothesis-5.4.1
collected 2 items
test_hw.py::TestHello::test_one running setUp
running test_one
running tearDown
PASSED
test_hw.py::TestHello::test_two running setUp
running test_two
running tearDown
PASSED
In a hobby project I intend to use nose for testing, I want to put all tests for specific classes into classes since these tests share setup and other functionality. But I can't seem to get nose to execute the setup methods inside the classes.
Here is an example class that is tested:
class mwe():
def __init__(self):
self.example = ""
def setExample(self, ex):
self.example = ex
The tests work, when I don't use classes:
from nose.tools import ok_
import mwe
exampleList = []
def setUp():
print("setup")
exampleList.append("1")
exampleList.append("2")
exampleList.append("3")
def test_Example():
print("test")
for ex in exampleList:
t = mwe.mwe()
t.setExample(ex)
yield check, t, ex
def check(e, ex):
ok_(e.example == ex)
The output is as expected:
setup
test
...
----------------------------------------------------------------------
Ran 3 tests in 0.004s
OK
When a test class is used, the setup method is not executed and therefore no tests are executed.
from nose.tools import ok_
import mwe
class TestexampleClass(object):
def __init__(self):
print("__init__")
self.exampleList = []
def setup(self):
print("setup class")
self.exampleList.append("1")
self.exampleList.append("2")
self.exampleList.append("3")
def test_ExampleClass(self):
print("test class")
for ex in self.exampleList:
t = mwe.mwe()
t.setExample(ex)
yield self.check, t, ex
def check(self, we, ex):
print("check class")
ok_(we.example == ex)
I'm fairly new to python and a newbie with nose, my question is, why is setup not executed? Where is the error in my code?
__init__
test class
----------------------------------------------------------------------
Ran 0 tests in 0.002s
OK
I will be glad for any feedback.
When I use the code from this Question on SO the setup method is executed, as I would expect it.
SOLUTION: After a lot of desperation I found the following:
Nose executes the the class level setup method before the execution of the yielded function, not when the test_* methods are called, as I expected and as is the case for other test_* methods. This obviously goes against the nose documentation:
Setup and teardown functions may be used with test generators. However, please note that setup and teardown attributes attached to the generator function will execute only once. To execute fixtures for each yielded test, attach the setup and teardown attributes to the function that is yielded, or yield a callable object instance with setup and teardown attributes.
Looking at the bug reports, I found the bug report on github.
A possible workaround is to use class level fixtures:
#classmethod
def setup_class(cls):
#do stuff
pass
Your test class needs to extend TestCase and the setup method needs to be called setUp
from unittest import TestCase
class TestUtils(TestCase):
def setUp(self):
self.x = 1
def test_something(self):
self.assertEqual(1, self.x)
which outputs
.
----------------------------------------------------------------------
Ran 1 test in 0.000s
OK
In Pyunit framework, I have question as below:
import unittest
class xyz(object):
def test_fuc(self):
print "test_fun"
pass
class abc(unittest.Testcase, xyz):
def setUp(self):
print "setUp"
def tearDown(self):
print "tearDown"
def test_one(self):
print "test_one"
pass
def test_two(self):
print "test_two"
pass
Output:
test_one
test_two
test_fun
but I need output like below:
test_one
test_fun
test_two
test_fun
Please suggest, How do I do it?
Unit tests (ie. unittest.TestCase methods) are supposed to be independant, and thus there is no point of running them twice.
If you want to do that, you probably should design your tests another way.
I need to set an order of execution for my tests, because I need some data verified before the others. Is possible to set an order?
class OneTestCase(unittest.TestCase):
def setUp(self):
# something to do
def test_login (self):
# first test
pass
def test_other (self):
# any order after test_login
def test_othermore (self):
# any order after test_login
if __name__ == '__main__':
unittest.main()
You can do it like this:
class OneTestCase(unittest.TestCase):
#classmethod
def setUpClass(cls):
# something to do
pass
def test_01_login (self):
# first test
pass
def test_02_other (self):
# any order after test_login
def test_03_othermore (self):
# any order after test_login
if __name__ == '__main__':
unittest.main(failfast=True, exit=False)
Tests are sorted alphabetically, so just add numbers to get your desired order. Probably you also want to set failfast = True for the testrunner, so it fails instantly, as soon as the first test fails.
Better do not do it.
Tests should be independent.
To do what you want best would be to put the code into functions that are called by the test.
Like that:
def assert_can_log_in(self):
...
def test_1(self):
self.assert_can_log_in()
...
def test_2(self):
self.assert_can_log_in()
...
Or even to split the test class and put the assertions into the setUp function.
class LoggedInTests(unittest.TestCase):
def setUp(self):
# test for login or not - your decision
def test_1(self):
...
When I split the class I often write more and better tests because the tests are split up and I can see better through all the cases that should be tested.