Test & Code

With conventional TDD, you write a failing test, get it to pass, then refactor.
Then run the tests again to make sure your refactoring didn't break anything.
But what if it did break something?
Kent Beck has been recommending to commit your code to revision control after every green test run.
Oddmund Strømme suggested a symmetrical idea to go ahead and revert the code when a test fails.
Kent writes that he hated the idea, but had to try it.
Then wrote about it last September.
And now we have TCR, "(test && commit) || revert".

What's it feel like to actually do this?
Well, Thomas Deniffel has been using it since about a month after that article came out.
In this episode, we'll hear from Thomas about his experience with it.

It's a fascinating idea. Have a listen and let me know what you think.

Special Guest: Thomas Deniffel.

Sponsored By:

• PyCharm Professional: Try PyCharm Pro for an extended 4 month trial before deciding which version you need. If you value your time, you owe it to yourself to try PyCharm. Promo Code: TESTANDCODE22

Links:

• test && commit || revert — Kent Beck's original article
• TCR: (test && commit || revert). How to use? Alternative to TDD? — Thomas Deniffel's article
• TCR Variants (test && commit || revert)
• TCR: A pulverizer for coding tasks — Another interesting opinion from someone else trying TCR - Jason Crawford
• (test && commit || revert) Questions Answered — Written after this interview.

A wonderful discussion with David Hussman. David and Brian look back at what all we've learned in XP, TDD, and other Agile methodologies, where things have gone awry, how to bring the value back, and where testing fits into all of this.

• How to build the wrong thing faster
• Agile vs Agility
• Product vs Process
• Where testing fits into software development practices.
• "Integration tests, there's a name that needs to be refactored desperately."
• Integration tests are "story tests". They tell the story of the product.
• XP and TDD and the relationship with tests
• To test for design, use microtests, xUnit style.
• User Advocy tests are often lacking, but are needed to learn about the product.
• "I just keep writing tests until I'm not scared anymore." - Kent Beck
• Dude's Law: Value = Why/How
• People often focus so much on the how that they forget about why they are doing something.
• Subcutaneous Tests
• "The hardest part of programming is thinking."
• Refactoring vs Repaving
• Agility means being able to quickly change direction
• During experimentation and learning, what matters isn't how much you got done, but how much you learn.
• "The best way to get automation is to make developers do manual tests."

Special Guest: David Hussman.

Sponsored By:

• Talk Python Training: Online video courses for Python developers
• Python Testing with pytest, 2nd edition: The fastest way to learn pytest and practical testing practices.
• Patreon Supporters: Help support the show with as little as $1 per month and be the first to know when new episodes come out.

Links:

• DevJam
• PNSQC 2015 How to Build the Wrong Thing Faster and Learn From It
• People's Front of Judea
• TDD on c2
• The waterfall model
• Test First Programming
• Dude's Law
• Subcutaneous Test

virtualenv supports six shells: bash, csh, fish, xonsh, cmd, posh. Each handles prompts slightly differently. Although the virtualenv custom prompt behavior should be the same across shells, Brian Skinn noticed inconsistencies. He set out to fix those inconsistencies. That was the start of an adventure in open source collaboration, shell prompt internals, difficult test problems, and continuous integration quirks.

Brian Skinn initially noticed that on Windows cmd, a space was added between a prefix defined by --prompt and the rest of the prompt, whereas on bash no space was added.

For reference, there were/are three nominal virtualenv prompt modification behaviors, all of which apply to the prompt changes that are made at the time of virtualenv activation:

1. If the environment variable VIRTUAL_ENV_DISABLE_PROMPT is defined and non-empty at activation time, do not modify the prompt at all. Otherwise:
2. If the --prompt argument was supplied at creation time, use that argument as the prefix to apply to the prompt; or,
3. If the --prompt argument was not supplied at creation time, use the default prefix of "() " as the prefix (the environment folder name surrounded by parentheses, and with a trailing space after the last paren.

Special Guest: Brian Skinn.

Sponsored By:

• Talk Python Training: Online video courses for Python developers
• HoneyBadger: When bad things happen, it's nice to know that Honeybadger has your back. 30% off for first 6 months when you mention Test & Code Podcast when signing up.
• PyCharm Professional: Try PyCharm Pro for 4 months and learn how PyCharm will save you time. Promo Code: TESTANDCODE22

Links:

• virtualenv
• Initial issue that started the adventure
• final PR
• pent: pent Extracts Numerical Text -- Mini-language driven parser for structured numerical data
• Lightening talk on pent

pytest plugins are an amazing way to supercharge your test suites, leveraging great solutions from people solving test problems all over the world. In this episode Michael and I discuss 15 favorite plugins that you should know about.

We also discuss fixtures and plugins and other testing tools that work great with pytest

• tox
• GitHub Actions
• Coverage.py
• Selenium + splinter with pytest-splinter
• Hypothesis

And then our list of pytest plugins:

1. pytest-sugar
2. pytest-cov
3. pytest-stress
4. pytest-repeat
5. pytest-instafail
6. pytest-metadata
7. pytest-randomly
8. pytest-xdist
9. pytest-flake8
10. pytest-timeout
11. pytest-spec
12. pytest-picked
13. pytest-freezegun
14. pytest-check
15. fluentcheck

That last one isn't a plugin, but we also talked about pytest-splinter at the beginning. So I think it still counts as 15.

Special Guest: Michael Kennedy.

Sponsored By:

• PyCharm Professional: Try PyCharm Pro for 4 months and learn how PyCharm will save you time. Promo Code: TESTANDCODE22

Links:

• pytest-sugar — changes the default look and feel of pyptest (e.g. progressbar, show tests that fail instantly)
• pytest-cov — run coverage.py from pytest
• pytest-stress — allows you to loop tests for a user defined amount of time.
• pytest-repeat — for repeating test execution
• pytest-instafail — shows failures and errors instantly instead of waiting until the end of test session.
• pytest-metadata — for accessing test session metadata
• pytest-randomly — randomly order tests and control random.seed
• pytest-xdist — distributed testing
• pytest-flake8 — pytest plugin to run flake8
• pytest-timeout — terminate tests after a certain timeout
• pytest-spec — display test execution output like a specification
• pytest-picked — run the tests related to the changed files (according to Git)
• pytest-freezegun — easily freeze time
• pytest-check — allows multiple failures per test
• fluentcheck — fluent assertions
• episode 104 — Top 28 pytest plugins with Anthony Sottile
• Python Testing with pytest — The easiest way to get up to speed with pytest fast. There's also a chapter dedicated to plugins that also teaches you how to write and test your own plugins.
• tox
• GitHub Actions
• Coverage.py
• pytest-splinter — provides a set of fixtures to use splinter for browser testing
• splinter — makes it easy to write automated tests of web applications
• hypothesis — property-based t...

Django has a handful of console commands to help manage and develop sites.
django-rich adds color and nice formatting. Super cool.
In a recent release, django-rich also adds nice colorized tracebacks to the Django test runner.

Links:

• django-rich · PyPI
• episode 181: Boost Your Django DX - Adam Johnson
• django-crispy-forms
• Python Developers Survey 2020 Results