Vicente G. Reyes
Vicente Garcia-Reyes

Vicente Garcia-Reyes

Django 2.2 Test Driven Development

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Vicente G. Reyes
·May 7, 2019·

3 min read

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95% into my first Django Website built by yours truly with the help of this book and something came into my mind. Testing.

I recently stumbled upon the words of Jacob Kaplan-Moss, one of Django's original creators, "Code without tests is broken as designed." this hit me in a way that I know to my self that I suck at designing, which motivated me to learn how to test.

"Writing tests is important because it automates the process of confirming that the code works as expected." - Django For Beginners

I tried two tests because obviously I had troubles with the first one and was getting an error:

AssertionError: 301 != 200
The first test I used was SimpleTestCase. It is a subclass of unittest.TestCase that adds some functionality

from django.test import SimpleTestCase

class PageTest(SimpleTestCase):

def test_portfolio_page_status_code(self): response = self.client.get("/portfolio") self.assertEquals(response.status_code, 200)

def test_blog_page_status_code(self): response = self.client.get("/blog") self.assertEqual(response.status_code, 200)

def test_home_page_status_code(self): response = self.client.get("") self.assertEquals(response.status_code, 200)

def test_quotes_page_status_code(self): response = self.client.get("/quotes/") self.assertEquals(response.status_code, 200)

but the traceback was:


FAIL: test_blog_page_status_code (personal_portfolio.tests.PageTest)

Traceback (most recent call last): File "/Users/user/dir/personal_portfolio/", line 11, in test_blog_page_status_code self.assertEqual(response.status_code, 200) AssertionError: 301 != 200

====================================================================== FAIL: test_portfolio_page_status_code


Traceback (most recent call last): File "/Users/user/dir/personal_portfolio/", line 7, in test_portfolio_page_status_code self.assertEquals(response.status_code, 200) AssertionError: 301 != 200

I went to StackOverflow to ask for help and this is what I got:

I told myself, there must be another way to test my code. I tested my patience by reading through the article and stumbled upon TransactionTestCase which inherits from SimpleTestCase to add some database-specific features.

from django.test import TransactionTestCase

class Personal_PortfolioTests(TransactionTestCase):

    def test_home_page_status_code(self):
    response = self.client.get('/')

    def test_portfolio_page_status_code(self):
    response = self.client.get('/portfolio/')

    def test_quotes_page_status_code(self):
    response = self.client.get('/quotes/')

    def test_blog_page_status_code(self):
    response = self.client.get('/blog/')

And viola!


Django’s TestCase class is a more commonly used subclass of TransactionTestCase that makes use of database transaction facilities to speed up the process of resetting the database to a known state at the beginning of each test. A consequence of this, however, is that some database behaviors cannot be tested within a Django TestCase class. For instance, you cannot test that a block of code is executing within a transaction, as is required when using select_for_update(). In those cases, you should use TransactionTestCase.

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