Using maxfail Command Line Option To Stop Test Suite After N Test Failures. PyTest offers a command-line option called maxfail which is used to stop test suite after n test failures.
Once you are in a TestCase , the stop() method for the TestResult is not used when iterating through the tests. Somewhat related to your question, if you are using python 2.7, you can use the -f/--failfast flag when calling your test with python -m unittest . This will stop the test at the first failure.
The skipping markers are associated with the test method with the following syntax − @py. test. mark.
pytest is a very robust framework that comes with lots of features. One such feature is the autouse fixtures, a.k.a xUnit setup on steroids. They are a special type of fixture that gets invoked automatically, and its main use case is to act as a setup/teardown function.
Pytest has the skip and skipif decorators, similar to the Python unittest module (which uses skip
and skipIf
), which can be found in the documentation here.
Examples from the link can be found here:
@pytest.mark.skip(reason="no way of currently testing this")
def test_the_unknown():
...
import sys
@pytest.mark.skipif(sys.version_info < (3,3),
reason="requires python3.3")
def test_function():
...
The first example always skips the test, the second example allows you to conditionally skip tests (great when tests depend on the platform, executable version, or optional libraries.
For example, if I want to check if someone has the library pandas installed for a test.
import sys
try:
import pandas as pd
except ImportError:
pass
@pytest.mark.skipif('pandas' not in sys.modules,
reason="requires the Pandas library")
def test_pandas_function():
...
The skip
decorator would do the job:
@pytest.mark.skip(reason="no way of currently testing this")
def test_func_one():
# ...
(reason
argument is optional, but it is always a good idea to specify why a test is skipped).
There is also skipif()
that allows to disable a test if some specific condition is met.
These decorators can be applied to methods, functions or classes.
To skip all tests in a module, define a global pytestmark
variable:
# test_module.py
pytestmark = pytest.mark.skipif(...)
You can mark a test with the skip
and skipif
decorators when you want to skip a test in pytest
.
@pytest.mark.skip(reason="no way of currently testing this")
def test_func_one():
...
The simplest way to skip a test is to mark it with the skip
decorator which may be passed an optional reason
.
It is also possible to skip imperatively during test execution or setup by calling the pytest.skip(reason)
function. This is useful when it is not possible to evaluate the skip condition during import time.
def test_func_one():
if not valid_config():
pytest.skip("unsupported configuration")
@pytest.mark.skipif(sys.version_info < (3, 6), reason="requires python3.6 or higher")
def test_func_one():
...
If you want to skip based on a conditional then you can use skipif
instead. In the previous example, the test function is skipped when run on an interpreter earlier than Python3.6.
Finally, if you want to skip a test because you are sure it is failing, you might also consider using the xfail
marker to indicate that you expect a test to fail.
I'm not sure if it's deprecated, but you can also use the pytest.skip
function inside of a test:
def test_valid_counting_number():
number = random.randint(1,5)
if number == 5:
pytest.skip('Five is right out')
assert number <= 3
If you want to skip the test but not hard code a marker, better use keyword expression to escape it.
pytest test/test_script.py -k 'not test_func_one'
Note: Here 'keyword expression' is basically, expressing something using keywords provided by pytest (or python) and getting something done. I above example, 'not' is a keyword.
For more info, refer this link.
More examples of keyword expression:Refer this answer
You may also want to run the test even if you suspect that test will fail. For such scenario https://docs.pytest.org/en/latest/skipping.html suggests to use decorator @pytest.mark.xfail
@pytest.mark.xfail
def test_function():
...
In this case, Pytest will still run your test and let you know if it passes or not, but won't complain and break the build.
You can divide your tests on set of test cases by custom pytest markers, and execute only those test cases what you want. Or the inverse, running all tests except the another set:
@pytest.mark.my_unit_test
def test_that_unit():
...
@pytest.mark.my_functional_test
def test_that_function():
...
And then, to run only one set of unit tests, as example:
pytest -m my_unit_test
Inverse, if you want to run all tests, except one set:
pytest -m "not my_unit_test"
How to combine several marks
More examples in official documentation
It looks more convenient if you have good logic separation of test cases.
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