Test & Code

By Brian OkkenTechnology Education How To

Test & Code episodes

March 12, 2021148: Coverage.py and testing packages
How do you test installed packages using coverage.py?
Also, a couple followups from last week's episode on using coverage for single file applications.

Links:
episode 147: Testing Single File Python Applications/Scripts with pytest and coverage
Specifying source files — Coverage.py documentation
Testing & Packaging - Hynek
ack
14 min
March 06, 2021147: Testing Single File Python Applications/Scripts with pytest and coverage
Have you ever written a single file Python application or script?
Have you written tests for it?
Do you check code coverage?
This is the topic of this weeks episode, spurred on by a listener question.
The questions:
For single file scripts, I'd like to have the test code included right there in the file. Can I do that with pytest?
If I can, can I use code coverage on it?
The example code discussed in the episode: script.py
def foo():
return 5
def main():
x = foo()
print(x)
if __name__ == '__main__': # pragma: no cover
main()
## test code
# To test:
# pip install pytest
# pytest script.py
# To test with coverage:
# put this file (script.py) in a directory by itself, say foo
# then from the parent directory of foo:
# pip install pytest-cov
# pytest --cov=foo foo/script.py
# To show missing lines
# pytest --cov=foo --cov-report=term-missing foo/script.py
def test_foo():
assert foo() == 5
def test_main(capsys):
main()
captured = capsys.readouterr()
assert captured.out == "5\n"

Suggestion by @cfbolz if you need to import pytest:
if __name__ == '__main__': # pragma: no cover
main()
else:
import pytest
12 min
February 28, 2021146: Automation Tools for Web App and API Development and Maintenance - Michael Kennedy
Building any software, including web apps and APIs requires testing.
There's automated testing, and there's manual testing.
In between that is exploratory testing aided by automation tools.
Michael Kennedy joins the show this week to share some of the tools he uses during development and maintenance.
We talk about tools used for semi-automated exploratory testing.
We also talk about some of the other tools and techniques he uses to keep Talk Python Training, Talk Python, and Python Bytes all up and running smoothly.
We talk about:
Postman
ngrok
sitemap link testing
scripts for manual processes
using failover servers during maintenance, redeployments, etc
gitHub webhooks and scripts to between fail over servers and production during deployments automatically
floating IP addresses
services to monitor your site: StatusCake, BetterUptime
the affect of monitoring on analytics
crash reporting: Rollbar, Sentry
response times
load testing: Locus

Links:
Python Bytes Podcast
Talk Python To Me Podcast
Talk Python Training
Postman
ngrok
StatusCake
Better Uptime
Rollbar
Sentry
Locust
12 requests per second in Python
48 min
February 18, 2021145: For Those About to Mock - Michael Foord
A discussion about mocking in Python with the original contributor of unittest.mock, Michael Foord.
Of course we discuss mocking and unittest.mock.
We also discuss:
testing philosophy
unit testing and what a unit is
TDD
where Michael's towel is, and what color
Micheal was instrumental in the building of testing tools for Python, and continues to be a pragmatic source of honest testing philosopy in a field that has a lot of contradictory information.

Links:
unittest.mock - Python docs
Mocks Aren't Stubs - Martin Fowler
pytest-mock
mock.patch
Autospeccing
Arrange Act Assert
testing-in-python mailing list
Classical and Mockist Testing — Classical and Mockist Testing
Test First Programming / Test First Development
episode 102: Cosmic Python, TDD, testing and external dependencies - Harry Percival
episode 132: mocking in Python - Anna-Lena Popkes
pytest
unittest - Python docs
pytest assert usage
30 best practices for software development and testing | Opensource.com
49 min
February 13, 2021144: TDD in Science - Martin Héroux
Test Driven Development, TDD, is not easy to incorporate in your daily development.
Martin and Brian discuss TDD and testing and Martin's experience with testing, TDD, and using it for code involved with scientific research.
We discuss lots of topics around this, including:
What is TDD?
Should research software be tested in order to be trusted?
Time pressure and the struggle to get code done quickly. How do you make time for tests also?
Is testing worth it for code that will not be reused?
Sometimes it's hard to know how to test something.
Maybe people should learn to test alongside learning how to code.
A desire for a resource of testing concepts for non-CS people.
Are the testing needs and testing information needs different in different disciplines?
Biology, Physics, Astrophysics, etc. Do they have different testing needs?
Do we need a "how to test" resource for each?

Special Guest: Martin Héroux.

Links:
Joy Division Album Cover
episode 140: Testing in Scientific Research and Academia - Martin Héroux — Martin's previous episode.
53 min
February 07, 2021143: pytest markers - Anthony Sottile
Completely nerding out about pytest markers with Anthony Sottile.
Some of what we talk about:
Running a subset of tests with markers.
Using marker expressions with and, or, not, and parentheses.
Keyword expressions also can use and, or, not, and parentheses.
Markers and pytest functionality that use mark, such as parametrize, skipif, etc.
Accessing markers with itermarkers and get_closest_marker through item.
Passing values, metadata through markers to fixtures or hook functions.
Links:
Registering markers
slow marker example in pytest documentation — Control skipping of tests according to command line option
pytest-repeat · PyPI
source code for pytest-repeat
Working with custom markers — pytest documentation
Using -k expr to select tests based on their name
Marker revamp and iteration, Historical Notes — pytest documentation
40 min
January 25, 2021142: MongoDB - Mark Smith
MongoDB is possibly the most recognizable NoSQL document database.
Mark Smith, a developer advocate for MongoDB, answers my many questions about MongoDB.
We cover some basics, but also discuss some advanced features that I never knew about before this conversation.

Special Guest: Mark Smith.

Links:
MongoDB
Everything You Know About MongoDB is Wrong!
Implementing Event Sourcing and CQRS pattern with MongoDB
35 min
December 30, 2020141: Visual Testing - Angie Jones
Visual Testing has come a long way from the early days of x,y mouse clicks and pixel comparisons. Angie Jones joins the show to discuss how modern visual testing tools work and how to incorporate visual testing into a complete testing strategy.
Some of the discussion:
Classes of visual testing:
problems with pixel to pixel testing
DOM comparisons, css, html, etc.
AI driven picture level testing, where failures look into the DOM to help describe the problem.
Where visual testing fits into a test strategy.
Combining "does this look right" visual testing with other test workflows.
"A picture is worth a thousand assertions" - functional assertions built into visual testing.
Baselining pictures in the test workflow.
Also discussed:
automation engineer
Test Automation University
Links:
Test Automation University
31 min
December 18, 2020140: Testing in Scientific Research and Academia - Martin Héroux
Scientists learn programming as they need it.
Some of them learn it in college, but even if they do, that's not their focus.
It's not surprising that sharing the software used for scientific research and papers is spotty, at best.
And what about testing?
We'd hope that the software behind scientific research is tested.
But why would we expect that?
We're lucky if CS students get a class or two that even mentions automated tests.
Why would we expect other scientists to just know how to test their code?
Martin works in research and this discussion is about software and testing in scientific research and academia.

Special Guest: Martin Héroux.

Links:
Python Testing with pytest: Simple, Rapid, Effective, and Scalable
Test Driven Development: By Example
My reaction to "Is TDD Dead?" - Python Testing
MartinHeroux/pliffy: Plotting differences with Python
PyBites Code Challenges
Python Morsels
Martin Héroux (@martin_heroux) / Twitter
Scientifically Sound
‪Martin Héroux‬ - ‪Google Scholar‬
spike2py · PyPI
pytest-mpl · PyPI
48 min
December 04, 2020139: Test Automation: Shifting Testing Throughout the Software Lifecycle - Nalin Parbhu
Talking with Nalin Parbhu about the software evolution towards more test automation and the creation of Infuse and useMango.
We talk a software development and "shift left" where automated tests and quality checks have moved earlier into the software lifecycle.
Software approaches and where quality fits in
Shift left
Test automation
Roles of software developers, SDETs (software development engineer in test), testers, QA, etc.
Developers doing testing and devops
Automated testing vs manual testing
Regression testing, UI testing, black bock testing
Unit testing, white box, API, end to end testing
User acceptance testing (UAT)
Mullet Methodology (Agile at the front, Waterfall at the back)
Waterwheel Methodology (Requirements -> iterative development -> QA)
What's an agile team?
Developer resistance to testing
Manifesto for agile software development
Iterative development
Adapting to change
Agility: being able to change course quickly
Special Guests: Nalin Parbhu and Ola Omiyale.
36 min