Run tests

Run tests#

This page focuses on the ways to run tests in unittest library.

Check:

Run from file#

If you have files listing all your tests, you can execute them using python3 -m unittest <path to file>. The path can be specified in two formats:

  • Sections separated by / slashes: system-like.

  • Sections separated by . dots: Python imports-like.

The following cell defines the unittest file that will be run later.

%%writefile run_tests_files/test.py
import unittest

class SomeTest(unittest.TestCase):
    def test(self):
        print("simple test")
        self.assertEqual(10,10)

Overwriting run_tests_files/test.py

You can run this test by specifying the file path to it as a parameter to the `python3 -m unittest’ command.

!python3 -m unittest run_tests_files/test.py

simple test
.
----------------------------------------------------------------------
Ran 1 test in 0.000s

OK

Or how to import this file into a Python program.

!python3 -m unittest run_tests_files.test

simple test
.
----------------------------------------------------------------------
Ran 1 test in 0.000s

OK

Tests package#

More complex programs require more complex tests. In this case, you need to put tests in packages (folders of modules). In such a case you can just run python -m unittest from the folder with tests - everything that can be interpreted as python package will be executed. Note Unittest will only identify modules starting with test_ as test modules.

The following cells prepare the structure of the package that we’ll use for the example.

%%bash
mkdir /tmp/run_test &> /dev/null | true
mkdir /tmp/run_test/inner &> /dev/null | true

%%writefile /tmp/run_test/test_first.py
from unittest import TestCase

class FirstTest(TestCase):
    def test_root(self):
        print("First test")

Writing /tmp/run_test/test_first.py

%%writefile /tmp/run_test/inner/test_inner.py
from unittest import TestCase

class InnerTest(TestCase):
    def test_root(self):
        print("Innter test")

Writing /tmp/run_test/inner/test_inner.py

Finally we got package with one test on the current folder and one hidden on the innter folder.

!cd /tmp/run_test && tree

.
├── inner
│   └── test_inner.py
└── test_first.py

2 directories, 2 files

By running python3 -m unittest from the working directory we got FirstTest executed, but not inner test.

%%bash
cd /tmp/run_test
python3 -m unittest

First test

.
----------------------------------------------------------------------
Ran 1 test in 0.000s

OK

This is because unittest doesn’t recognize inner as a module. You can fix this by adding __init__.py to the inner.

%%writefile /tmp/run_test/inner/__init__.py
pass

Writing /tmp/run_test/inner/__init__.py

After that, both tests ran as expected.

%%bash
cd /tmp/run_test
python3 -m unittest

Innter test

..

First test

----------------------------------------------------------------------
Ran 2 tests in 0.000s

OK

Naming#

You have to name files and classes in a special way to run them with unittest.

By default, if you run unittest without any special modifications it will run all files that start with test. All classes that inherit from unitttes.TestCase are interpreted as test classes. In each test class, all methods starting with test will be executed.

The following cells creates testing project with different options.

  • Files that starts with test and not.

  • Classes that contains Test in it’s name and not.

  • Methods that starts with test and not.

So we can learn in which cases naming is important and in which cases is not.

!rm /tmp/testing_folder &> /dev/null & mkdir /tmp/testing_folder &> /dev/null

%%writefile /tmp/testing_folder/test_file.py
from unittest import TestCase

class TestClass(TestCase):
    def test_method(self):
        print("test method in test class in test file")
    
    def some_method(self):
        print("some method in test class in test file")


class SomeClass(TestCase):
    def test_method(self):
        print("test method in some class in test file")

Writing /tmp/testing_folder/test_file.py

%%writefile /tmp/testing_folder/some_file.py
from unittest import TestCase

class TestClass(TestCase):
    def test_method(self):
        print("test method in test class in some file")

Writing /tmp/testing_folder/some_file.py

The following cell runs unittest without any additional configuration in the “project” folder.

%%bash
cd /tmp/testing_folder
python3 -m unittest

test method in some class in test file
test method in test class in test file

..
----------------------------------------------------------------------
Ran 2 tests in 0.000s

OK

You can understand from the messages:

  • File name is important - because test in some_file.py wasn’t executed.

  • Name of the method is important - because TestClass.some_method wasn’t executed.

  • Name of the TestCase child doesn’t matter - because SomeClass.test_method was executed.

Skip case#

If you want some child of unittest.TestCase not to be executed by unittest you can wrap it with the unittest.skip decorator - unittest will ignore it.

The following cell creates test file with unittest.TestCase wrapped in the unittest.skip decorator.

%%writefile /tmp/skip_test.py
import unittest

@unittest.skip("some text")
class TestClass(unittest.TestCase):
    def test_method(self):
        print("test_method executed")

Overwriting /tmp/skip_test.py

The following cell runs tests.

%%bash
cd /tmp
python3 -m unittest skip_test.py
true

s
----------------------------------------------------------------------
Ran 1 test in 0.000s

OK (skipped=1)

As a result, no tests are executed - but one is skipped.

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