Run python unit tests as an option of the program - python

I'm a noob in python.
I'm kind of confused about how the python unit test are supposed to be built and run for the actual applications, i.e. if I have a program that starts from a main method I should be able to start unit tests for this program via the same entry point?
So I'm trying to create a program one of the parameters for which should tell the program to run unit tests instead of normal execution (see below) but also being able to accept all parameters that unittest.main() can accept. I would appreciate any advice about better approach of separating the actual program execution and unit tests in pythonic way or any help with the example below if the approach I'm taking is correct:
class MyClass
def write_to_file(self, file):
open(file, 'w').write("Hello world!")
class MyClassTest (unittest.TestCase)
self.mc = MyClass()
self.test_file = os.path.join(os.path.curdir, "a_file.txt")
def setUp(self):
pass
def test_write_to_file(self):
try:
write_to_file(self.test_file)
except IOError:
self.fail("Error!")
if __name__== "__main__":
parser = argparse.ArgumentParser(description="Some desc")
group = parser.add_mutually_exclusive_group()
group.add_argument("-w", "--write", help=': write hello world to given file')
group.add-argument("-t", "--test", help=': run unit tests, use "all" to run all tests')
args = parser.parse_args(sys.argv[1:])
mcl = MyClass()
if args.write:
mcl.write_to_file(args.write)
# below is the questionnable part
if args.test:
#removing -t or --test argument because otherwise unittest.main() will complain
del sys.argv[1:]
if args.test == "all":
unittest.main()
else:
# Adding the argument that was specified after the -t into the sys.argv to be picked up by the unittest.main() - doesn't work correctly (1)
sys.argv.append(args.test)
unittest.main()
(1) If I'm specifying executing MyClass with -t MyTestCase option i expect it to be able to run in accordance with the help message unittest.main() but it says there is an AttributeError: 'module' object has no attribute MyTestCase
Thanks!

I would put the class (the "unit" under test) in a file by itself, and the "main" program and unit tests in two more files. The latter would be executable scripts; the first would simply be imported by them.

Related

Why doesn't the test work without if __name__ == '__main__'?

I can't figure out why without the line if __name__ == '__main__': before unittest.main() the test does not find?
I am using the latest version of PyCharm. I know that in order for the test to work in PyCharm, you can not add these lines at all, but I want to deal with the logic itself: why without the line if __name__ == '__main__': the result is as in the screenshot, but if you add it, then everything works?
Code:
import unittest
from name_function import get_formatted_name
class NamesTestCase(unittest.TestCase):
"""Tests for 'name_function.py'."""
def test_first_last_name(self):
"""Are names like 'Janis Joplin' working correctly?"""
formatted_name = get_formatted_name('janis', 'joplin')
self.assertEqual(formatted_name, 'Janis Joplin')
unittest.main()
There is only one function in the name_function module:
def get_formatted_name(first, last):
"""Builds a formatted full name."""
full_name = f"{first} {last}"
return full_name.title()
Result:
No tests were found
/Users/xxx/Documents/PycharmProjects/Book/venv/bin/python
"/Applications/PyCharm
CE.app/Contents/plugins/python-ce/helpers/pycharm/_jb_unittest_runner.py"
--path /Users/xxx/Documents/PycharmProjects/Book/testing.py
Testing started at 00:22 ...
-------------------------------------------------------------------> Ran 0 tests in 0.000s
OK
Launching unittests with arguments python -m unittest
/Users/xxx/Documents/PycharmProjects/Book/testing.py in
/Users/xxx/Documents/PycharmProjects/Book
Process finished with exit code 0
Empty suite
Empty suite
I am running the testing.py module as the main program, but judging by the answer line PyCharm is running the test via python -m unittest testing.NamesTestCase
I additionally checked the value of the global variable __name__ and indeed it has the value testing, as if testing was imported. Although I launch it initially.
Please explain why in this case the startup script differs from the standard one and when testing.py starts it runs it through unittest? I really want to finally understand this issue. Also don't understand why, in this case, if it initially runs through unittest, unittest.main() doesn't run normally without additional checking if __name__ == '__main__':?

Python - How to mask a class from being executed in unittest on runtime

Please see the code below. I was trying to implement a test suite for my project
import unittest
class TestClass1(unittest.TestCase):
def test_1_first(self):
print("First test case")
def test_2_second(self):
print("Second test case")
class TestClass2(unittest.TestCase):
def test_3_third(self):
print("Third test case")
def test_4_fourth(self):
print("Fourth test case")
if __name__ == "__main__":
# val = 1 <-- getting from user
# if val == 1:
# Execute test cases in TestClass2
# else
# Execute test cases in TestClass1\
unittest.main()
I will get the class name as command line argument and I need to run each class of test according to the argument. Means I need to select and run some classes of test cases on runtime. So can any one help me to prevent a class from unit test execution at runtime? The problem is It's not allowed to use the method like passing class name while execution
unittest.main() already parses sys.argv to allow the running of specific classes or individual tests.
For example, if your script is named test.py, you can run the following to run just TestClass1:
python test.py __main__.TestClass1
Or the following to run just TestClass1.test_1_first:
python test.py __main__.TestClass1.test_1_first
If you wish to do it in your script, you can pass the name of test you want to run as the defaultTest argument:
unittest.main(defaultTest='__main__.TestClass1')
That is already built-in. You can run specific class via command:
python -m unittest test_module.TestClass1
If you really need to do it in your scpript, you can pass your classes to unittest.TestLoader().loadTestsFromName and then run test suite with unittest.TextTestRunner().run(suite). It will look something like this:
test_suite = unittest.TestLoader().loadTestsFromName('__main__.TestClass1')
unittest.TextTestRunner().run(test_suite)

PyCharm doesn't appear to run all unit tests

I have a problem running unittests in pycharm. The first class 'KnownValues' runs but the other class doesn't get checked at all.
import roman
import unittest
class KnownValues(unittest.TestCase):
def test_too_large(self):
'''to_roman should fail with large input'''
self.assertRaises(roman.OutOfRangeError, roman.to_roman, 4000)
def test_too_small(self):
ls = [0,-1,-25,-60]
for x in ls:
self.assertRaises(roman.OutOfRangeError, roman.to_roman, x)
def test_non_int(self):
ls = [1.5, -6.5, 6.8,12.9, "hello wold", "nigga123"]
for x in ls:
self.assertRaises(roman.TypeError, roman.to_roman, x)
class Test2(unittest.TestCase):
def test1(self):
assert 1 == 1
if __name__ == '__main__':
unittest.main()
Start all of your test functions with test. Many people use underscores to separate words, so a lot of people end up with tests starting with test_, but test is all that is required.
When having trouble in the GUI, you can check how your tests are running from the command line.
python test.py
or
python -m test
One problem that you might run into is that you have defined your tests within classes, and when running them through the GUI, the GUI has automatically discovered them for you. Be sure to include the lines at the end of your test file directing the interpreter to use the main function built into unittest.
if __name__ == '__main__':
unittest.main()
Keep in mind, you can optionally run the tests in only one of your classes at a time:
python tests.py KnownValues
python tests.py Test2
In PyCharm, it should automatically discover all the test classes. You still have the option of running only one class at a time. Choose Run->Edit Configurations to see the options that you are currently running under. Using command line parameters you can control running fewer or more tests.
As you can see, you can choose to run a script, a class, or a method. Be sure to set the name of your run configuration such that it reflects the scope of what you are running.

Python unittest report passed test

Hello I have a test module like the following under "test.py":
class TestBasic(unittest.TestCase):
def setUp(self):
# set up in here
class TestA(TestBasic):
def test_one(self):
self.assertEqual(1,1)
def test_two(self):
self.assertEqual(2,1)
if __name__ == "__main__":
unittest.main()
And this works pretty good, but I need a way to print which test passed, for example I could print the output to the console:
test_one: PASSED
test_two: FAILED
Now the twist, I could add a print statement right after the self.assertEqual() and that would be a passed test and I could just print it, but I need to run the test from a different module, let's say "test_reporter.py" where I have something like this:
import test
suite = unittest.TestLoader().loadTestsFromModule(test)
results = unittest.TextTestRunner(verbosity=0).run(suite)
at this point with results is when I build a report.
So please any suggestion is welcome
Thanks !!
Like Corey's comment mentioned, if you set verbosity=2 unittest will print the result of each test run.
results = unittest.TextTestRunner(verbosity=2).run(suite)
If you want a little more flexibility - and you might since you are creating suites and using test runners - I recommend that you take a look at Twisted Trial. It extends Python's unittest module and provides a few more assertions and reporting features.
Writing your tests will be exactly the same (besides subclassing twisted.trial.unittest.TestCase vs python's unittest) so your workflow won't change. You can still use your TestLoader but you'll have the options of many more TestReporters http://twistedmatrix.com/documents/11.1.0/api/twisted.trial.reporter.html.
For example, the default TestReporter is TreeReporter which returns the following output:

Python unittest - invoke unittest.main() with a custom TestSuite

I'm making unittests with python. I am not using any automatical test discovery. I am assembling TestCases into a TestSuite manually.
I can run these tests with unittest.TextTestRunner().run(suite), I would like to run them with unittest.main() so that I can use command line options (like -v/--failfast). The documentation says that unittest.main() can take a TestRunner option.
How to convert my TestSuite into a TestRunner?
Near duplicate of How to run a testsuite with unittest.main (answer copy-and-pasted):
You can't pass a TestSuite to main, check out the constructor of unittest.main.TestProgram (which is was unittest.main actually is) and how this class works. The first argument if anything is the module name, not a testsuite.
main() actually takes its arguments from sys.argv, as it is actually intended to be used from the command line and not from within a program. It's just common to do so for convenience.
Do nothing except be sure you have this in your unit test module.
if __name__ == '__main__':
unittest.main(failfast=True)
http://docs.python.org/library/unittest.html#unittest.main
From the documentation...
unittest.main( failfast=True, testRunner=unittest.TextTestRunner )

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