1. 1
Welcome
Easy
User Interaction testing
with webtest

2. 2
About your speaker
●
Kees Hink
– Passionate about testing
– Likes Django
●
Developer at Four Digits
– We do web stuff
– We use Python, Django, Wagtail CMS, React
– We don’t like stuff breaking when we touch it

3. 3
Talk outline
●
I have 38 slides
– Includes “question break” slides
●
Introduce Django
●
Show Django testing (slide 13

4. 4
Before we start
●
Why do we test
– Make sure all parts keep working through changes
– Show how things are supposed to work
●
What do we test
– Everything
– Well, almost. No framework stuff.

5. 5
Too much testing?

6. 6
Our tutorial project
●
Tournament pool app
●
Code on github: khink/django-tutorial-
tournament-pool

7. 7
The main screen

8. 8
Add a prediction

9. 9
Django admin list

10. 10
Django admin list

11. 11
Django admin detail

12. 12
Question break
When you use “git blame”

13. 13
Testing in Django
●
Basics are documented in the excellent
Django tutorial
●
docs.djangoproject.com/intro/

14. 14
The Django model

15. 15
Example unit test

16. 16
Example view

17. 17
Example view test

18. 18
Example create view

19. 19
Test form submit?
●
Django docs don’t say how

20. 20
Integration: fake POST

21. 21
Unit: Test Django Form

22. 22
Issues with that
●
They’re perfectly good tests
●
But they don’t test what the user actually
does / sees
●
Testing the form tests a specific
implementation (the Django way)

23. 23

24. 24
Introducing Webtest
●
docs.pylonsproject.org/projects/webtest/
●
For interacting with HTML as served by
WSGI apps
●
Only uses HTML elements (does not, for
example use Django Form class)

25. 25
Inspect HTML form

26. 26
Webtest form submit

27. 27
Replaces the
integration test

28. 28
Some features
●
Intuitive API
●
fails on 500/404 errors
– unless you specify otherwise

29. 29
Question break

30. 30
More intuitive asserts

31. 31
As pytest method

32. 32
Search in HTML
●
response.html gives a BeautifulSoup
object for easy HTML searching (details in
Martijn Jacobs’ blog post)

33. 33
response.showbrowser()

34. 34
Question break

35. 35
More pros?
●
Please try it out
●
docs.pylonsproject.org/projects/webtest/

36. 36
To summarize
●
Webtest can replace the “integration
tests”

37. 37
That’s it!
●
Thank you for being here
●
Slides will be linked from Mastodon:
toot.community/@keeshink
●
There will also be a blog post about this,
watch fourdigits.nl/blog

38. 38
Question break