Unit tests

def add(a, b):
    return a + b

import unittest


class TestNotebook(unittest.TestCase):
    def test_add(self):
        self.assertEqual(add(2, 2), 5)


unittest.main(argv=[""], verbosity=2, exit=False)

test_add (__main__.TestNotebook.test_add) ... FAIL

======================================================================
FAIL: test_add (__main__.TestNotebook.test_add)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/tmp/ipykernel_8759/2216555184.py", line 6, in test_add
    self.assertEqual(add(2, 2), 5)
AssertionError: 4 != 5

----------------------------------------------------------------------
Ran 1 test in 0.001s

FAILED (failures=1)

<unittest.main.TestProgram at 0x1065794d0>

Alternatively, ipython-unittest can also be used. This enables the following Cell Magics to be used in iPython:

• %%unittest_main executes test cases that are defined in a cell

• %%unittest_testcase creates a test case with the function defined in a cell and executes it

• %%unittest converts Python assert to unit test functions

• %%external to perform external unit tests

• %%write {mode} to write external files

%reload_ext ipython_unittest

%%unittest_main
class MyTest(unittest.TestCase):
    def test_1_plus_1_equals_2(self):
        sum = 1 + 1
        self.assertEqual(sum, 2)

    def test_2_plus_2_equals_4(self):
        self.assertEqual(2 + 2, 4)

Success

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

OK

<unittest.runner.TextTestResult run=2 errors=0 failures=0>

%%unittest_testcase
def test_1_plus_1_equals_2(self):
    sum = 1 + 1
    self.assertEqual(sum, 2)

def test_2_plus_2_equals_4(self):
    self.assertEqual(2 + 2, 4)

Success

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

OK

<unittest.runner.TextTestResult run=2 errors=0 failures=0>

%%unittest
"1 plus 1 equals 2"
sum = 1 + 1
assert sum == 2
"2 plus 2 equals 4"
assert 2 + 2 == 4

Success

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

OK

<unittest.runner.TextTestResult run=2 errors=0 failures=0>

By default, Docstring separates the unit test methods in this magic. However, if docstrings are not used, the Cell Magics create one for each assert method.

These Cell Magics support optional arguments:

• -p (--previous) P

  puts the cursor in front of P cells (default -1 corresponds to the next cell)

  However, this only works if jupyter_dojo is also installed.

• -s (--stream) S

  sets the ooutput stream (default is: sys.stdout)

• -t (--testcase) T

  defines the name of the TestCase for %%unittest and %%unittest_testcase

• -u (--unparse)

  outputs the source code after the transformations