Example of Unitest

Creating Simple Unittest

https://www.youtube.com/watch?v=1Lfv5tUGsn8&ab_channel=Socratica

Given function to calculate the circle area:

from math import pi

def circle_area(r):
	#return pi times r square
	return pi*(r**2)

Structuring the Unittest Module:

There two method of structuring the unittest module which is:

1. writing the unittest module within same dir as the main module:

.
├── themainmodule.py
└── themainmodule_test.py

0 directories, 2 files

2. create special folder for test module only:

.
├── src
│   └── themainmodule.py
└── test
    └── test_themainmodule.py

2 directories, 2 files

Writing the Unittest Function

import unitttest
from math import pi
from themainmodule import circle_area

class TestCircleArea(unittest.TestCase):
	def test_area(self):
		self.assertAlmostEqual(circle_area(1), pi)
		self.assertAlmostEqual(circle_area(0), 0)
		self.assertAlmostEqual(circle_area(2.5) pi*2.5**2)

Running the Unittest:

Running from python module using the module option:

$ python -m unittest themainmodule_test

Running from the module but within the dir so python can find the test file itself:

$ python -m unittest

Running from the themainmodule file directly:

$ python themainmodule.py

** need this snippet:

if __name__ == '__main__':
	unittest.main()

Test the Exception with Unitest:

def test_values(self):
	#this error need to be raise else will fail
	#parameter: error, function, function's parameter
	self.assertRaises(ValueError, circle_area, -2)

Without any exception set inside of the function, this unittest will fail, since when testing the -2 value, the function will just return the number instead of flag this the negative number is error, to fix this, we need to add the check inside of the circle_area function and raise error if number is negative.

Raising the error when value negative:

def circle_area(r):
	if r < 0:
		raise ValueError('The number is negative')
	#return pi times r square
	return pi*(r**2)
python

Running the unittest again now will show passing unittest since error is raise when r value is negative.

### Raising the type error when inserted number is not integer:
### from the circle_area function:
```python
def circle_area(r):
	if type(r) not in [float, int]:
		raise TypeError('The provided radius is non int or float')
	if r < 0:
		raise ValueError('The number is negative')
	#return pi times r square
	return pi*(r**2)

From the unittest function:

def test_types(self):
	#check to make sure non int will raise error
	self.assertRaises(TypeError, circle_area, 5j)
	self.assertRaises(TypeError, circle_area, 'hi')
	self.assertRaise(TypeError, cicle_area, True)

Get Method Documentation:

There's many assert method inside of unittest module, to get specific help on what certain assert method does, is simply use the help method on the assert method.

Using help method to get documentation:

import unittest

help(unittest.TestCase.assertEqual)