Test & Code

What flavor of TDD do you practice?  In this episode we talk about: Classical vs Mockist TDD Detroit vs London (I actually refer to it in the episode as Chicago instead of Detroit. Oh well.) Static vs Behavior Inside Out vs Outside In Double Loop TDD BDD FDD Tracer Bullets Rules of TDD Team Structure Lean TDD  This is definitely an episode I'd like feedback on. Reach out to me for further question...

Software development processes create value, and have waste, in the Lean sense of the word waste.  Lean manufacturing and lean software development changed the way we look at value and waste.  This episode looks at lean definitions of waste, so we can see it clearly when we encounter it. I'm going to use the term waste and value in future episodes. I'm using waste in a Lean sense, so we can look a...

Should your code be DRY or DAMP or something completely different?  How about your test code? Do different rules apply?  Wait, what do all of these acronyms mean? We'll get to all of these definitions, and then talk about how it applies to both production code and test code in this episode.  Links: The Pragmatic Programmer, 20th Anniversary Edition Don't repeat yourself - Wikipedia a-ha - Take On...

When learning data science and machine learning techniques, you need to work on a data set.  Matt Harrison had a great idea: Why not use your own Twitter analytics data?  So, he did that with his own data, and shares what he learned in this episode, including some of his secrets to gaining followers. In this episode we talk about: Looking at your own Twitter analytics data. Using Python, pandas, J...

Iterative processes that include writing test code and production code together, such as TDD, help make coding fun.  All of us that care about developing quality code with the help of testing can learn from each other, regardless of programming language. Today we step outside our normal Python comfort zone and talk with Gio about TDD in Swift. Gio Lodi, author of TDD in Swift, joins the show to di...

pre-commit started as a framework for running linters and code formatters during git actions via git hooks. It's grown and expanded and now supports an extensive list of languages and actions and manual running of actions. But even at it's core, it's great for letting computers nitpick about whitespace and formatting, so that code reviews can focus on architecture and design. Anthony Sottile discu...

Flake8 is a command-line tool for linting Python projects.   By default, it includes lint checks provided Pyflakes, pycodestyle, and McCabe  It's also a platform, and allows plugins to extend the checks.  Flake8 will run third-party extensions if they are found and installed. But what does all of that mean? Anthony Sottile is a maintainer of flake8 and has kindly offered to explain it to us. Links...

Tim Ottinger has four questions that work great in many situations, from doing homework, to cooking, to writing code, to entire software projects. They are actually awesome questions to ask during a software project. We discuss the questions, where they came from, and look at some uses in software. The questions: What is it that needs to be done? What do we need in order to do it? Where can we get...

You need tests for your web app. And it has a database. What do you do with the database during testing? Should you use the real thing? or mock it? Jeff Triplett says don't mock it. In this episode, we talk with Jeff about testing web applications, specifically Django apps, and of course talk about the downsides of database mocking. Links: "🤔 In ~12 years, I have never seen a case where mocking a...

Playwright is an end to end automated testing framework for web apps with Python support and even a pytest plugin. Links: Playwright for Python Why Playwright? playwright-pytest

I always learn a lot when I talk to Brett, and this episode is no exception.  We talk about the packaging workflow, tools, changes, pyproject.toml, flit, setuptools, and so much more.  I hope you learn as much as I did in this great discussion. Links: pytest-srcpaths Python Packaging User Guide pypa/packaging: Core utilities for Python packages flit and requires-python Extending and Embedding the...

Adventure, or Colossal Cave Adventure, was written between 1975 and 1977 in Fortran. Brandon Rhodes ported it to Python 3, initial release in 2011, and still maintains it. We talk to Brandon about this wonderful game. YOU ARE STANDING AT THE END OF A ROAD BEFORE A SMALL BRICK BUILDING. AROUND YOU IS A FOREST. A SMALL STREAM FLOWS OUT OF THE BUILDING AND DOWN A GULLY. >>> east A bit later....

Coming up with a testing strategy doesn't have to be stressful. Prioritizing features to test, and generating test cases for each feature can be fairly quick and painless. This episode covers a strategy for both that can be applied to many types of software.

Corey Quinn is the Chief Cloud Economist at The Duckbill Group. He's also a podcaster and writes a newsletter. And he also automates things with Python. But he doesn't write tests. Let's find out why. Reason for the interview. Rough summary of a twitter conversation: Corey: What podcasts should I try to get an invite onto? ToonArmyCaptain: Python Bytes, Test & Code, Talk Python Corey: But... I...

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

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 discuss...

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 t...

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 i...

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 qui...

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 t...

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 w...

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,...

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 t...

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 enginee...

Your test suite tells you about the quality of your code under test.  Mutation testing is a way to tell you about the quality of your test suite.  Anders Hovmöller wrote mutmut for mutation testing in Python, and can be used with pytest, unittest, and others. In this episode, Anders explains mutation testing, how mutation testing with mutmut works, and good workflows. Special Guest: Anders Hovmöll...