swizec.com

#### Senior Mindset Book

Get promoted, earn a bigger salary, work for top companies

# Simple trick for testing forms full of checkboxes with django

In late 2011 I hope we can all agree that unit testing is pretty important when creating websites or almost anything. Doesn't really matter whether you prefer a blackbox integration testing approach or a strict unit testing style. What matters is that you have tests.

But what do you do when you want to test a form with a bunch of checkboxes?

You want to make sure all combinations of on/off tests are working. But with even just 6 checkboxes that's 2^6=64 test and ... well nobody in their right mind is going to write that many tests are they?

Last weekend I came up with a simple solution to this problem, dare I say elegant.

The approach is to make a list of checkboxes, then generate binary numbers from 0 to 2^(length of list). Then simply iterate over the generated binary numbers, pick all the checkboxes with a corresponding true bit in the number and run its test - the tests are lambda functions in a dictionary.

My code was complicated slightly because I had two distinct sets of checkboxes that had to be tested separately-ish, but here's what this basically looks like in code.

_columns = ['job_code', 'location_in', 'location_out', 'shift_report']

def checkboxes(self):
checks = []

for i in range(2**len(self._columns):
column_switch = bin(j)[2:].rjust(4, '0')

checks.append([name for (yes, name) in
zip(column_switch, self._columns) if int(yes)])

return checks

You also need to define the actual tests for all the checkboxes, deciding how thorough to be is a matter of personal taste, I like to test for the smallest possible symptom.

_column_checks = {
'job_code': {True: lambda r:
self.assert_('Job Code' in r.content,
"no code column"),
False: lambda r:
self.assert_('Job Code' not in r.content,
"is code column")},
# and so on (this example has been violently snipped, likely missing a } or two

' in r.content, "no code column"), False: lambda r: self.assert_('Job Code

' not in r.content, "is code column")}, # and so on

And finally the whole thing becomes a simple loop

for checkboxes in self.checkboxes():
# do a bunch of posts to django to set everything up

for check in _column_checks.keys():
_column_checks[check][check in checkboxes['columns']](response)

And that's it. Simple easily modifiable code to test every possible combination of all checkboxes in a form.

Published on December 2nd, 2011 in Checkbox, django, Programming, python, Software testing, Tick (check mark), Uncategorized, Unit testing

#### Continue reading about Simple trick for testing forms full of checkboxes with django

Semantically similar articles hand-picked by GPT-4

### Senior Mindset Book

Get promoted, earn a bigger salary, work for top companies

Have a burning question that you think I can answer? Hit me up on twitter and I'll do my best.

Who am I and who do I help? I'm Swizec Teller and I turn coders into engineers with "Raw and honest from the heart!" writing. No bullshit. Real insights into the career and skills of a modern software engineer.

Want to become a true senior engineer? Take ownership, have autonomy, and be a force multiplier on your team. The Senior Engineer Mindset ebook can help 👉 swizec.com/senior-mindset. These are the shifts in mindset that unlocked my career.

Curious about Serverless and the modern backend? Check out Serverless Handbook, for frontend engineers 👉 ServerlessHandbook.dev

Want to Stop copy pasting D3 examples and create data visualizations of your own? Learn how to build scalable dataviz React components your whole team can understand with React for Data Visualization

Want to get my best emails on JavaScript, React, Serverless, Fullstack Web, or Indie Hacking? Check out swizec.com/collections

Did someone amazing share this letter with you? Wonderful! You can sign up for my weekly letters for software engineers on their path to greatness, here: swizec.com/blog

Want to brush up on your modern JavaScript syntax? Check out my interactive cheatsheet: es6cheatsheet.com

By the way, just in case no one has told you it yet today: I love and appreciate you for who you are ❤️

Created by Swizec with ❤️