One of the beautiful things about Sublime Merge¹ (and git/diffs) is that you can see exactly what has changed in complex expected values in tests to ensure that you’re updating the tests without overlooking regressions.

(This is from the Markdown page loader tests in Kitten², as I’m refactoring to implement the upcoming breaking change in the stateful components API³ as it affects the generated code for stateful layout components in Markdown pages.)

¹ Which I always have running, full-screen on its own monitor.
² https://kitten.small-web.org
³ Currently experimental and undocumented but that should change once this breaking change is implemented.

#git #diff #unitTests #tape #SublimeMerge #Kitten #SmallWeb #web #dev #developerExperience

𝐓𝐨𝐝𝐚𝐲, 𝐀𝐩𝐫𝐢𝐥 27, is the last day to secure your spot at the 𝐞𝐚𝐫𝐥𝐲-𝐛𝐢𝐫𝐝 𝐫𝐚𝐭𝐞 for my workshop 𝐖𝐞𝐥𝐥-𝐁𝐚𝐥𝐚𝐧𝐜𝐞𝐝 𝐓𝐞𝐬𝐭-𝐃𝐫𝐢𝐯𝐞𝐧 𝐃𝐞𝐯𝐞𝐥𝐨𝐩𝐦𝐞𝐧𝐭. Join us on 𝐌𝐚𝐲 21-22, 2026 at 𝐓𝐡𝐞 𝐁𝐫𝐚𝐢𝐧 𝐄𝐦𝐛𝐚𝐬𝐬𝐲 𝐢𝐧 𝐀𝐧𝐭𝐰𝐞𝐫𝐩 .

Don’t miss this final chance to invest in your skills at a reduced price.

🔗 𝐒𝐞𝐜𝐮𝐫𝐞 𝐲𝐨𝐮𝐫 𝐬𝐩𝐨𝐭 𝐧𝐨𝐰.

For more information: https://principal-it.eu/training/well-balanced-test-driven-development.html

#tdd #testdrivendevelopment #unittests #unittesting #softwaredesign

Letting the implementation details of the Subject Under Test seep into your test code quickly becomes problematic. It harms readability, forcing readers to decipher the test’s behavior, sometimes even debug it, just to understand what’s happening. Tests should be simple and easy to understand! That’s why it’s crucial to keep the domain knowledge in the production code, and out of your tests.

https://principal-it.eu/2020/09/prevent-domain-knowledge-from-sneaking-into-solitary-tests/

#tdd #testdrivendevelopment #unittests #unittesting #softwaredesign

Today, I have written 15 #UnitTests, and fixed a bunch of bugs that they'd revealed. This means that my kernel is now crashing later in the start-up process than it was this morning. Victory!

#OSDev

Struggling with brittle tests that slow you down? Join my 𝐖𝐞𝐥𝐥-𝐁𝐚𝐥𝐚𝐧𝐜𝐞𝐝 𝐓𝐞𝐬𝐭-𝐃𝐫𝐢𝐯𝐞𝐧 𝐃𝐞𝐯𝐞𝐥𝐨𝐩𝐦𝐞𝐧𝐭workshop on 𝐌𝐚𝐲 21-22, 2026 in Antwerp! Learn how to write reliable, maintainable tests that help you think about software design and prevent defects. Early -bird tickets are available until 𝐀𝐩𝐫𝐢𝐥 19.

For more information: https://principal-it.eu/training/well-balanced-test-driven-development.html

#tdd #unittests #softwaredesign #softwarecrafting #xp

“I’m writing unit tests because I have to. They just confirm that my code works, which I already know. They are tedious to write, and often stop working when I change the implementation of the system. Maintaining unit tests is often difficult and takes a lot of time out of my day.”

Does this sound familiar? Then you might be interested in my workshop, 𝐖𝐞𝐥𝐥-𝐁𝐚𝐥𝐚𝐧𝐜𝐞𝐝 𝐓𝐞𝐬𝐭-𝐃𝐫𝐢𝐯𝐞𝐧 𝐃𝐞𝐯𝐞𝐥𝐨𝐩𝐦𝐞𝐧𝐭, on 21 𝐚𝐧𝐝 22 𝐌𝐚𝐲 2026 𝐚𝐭 𝐓𝐡𝐞 𝐁𝐫𝐚𝐢𝐧 𝐄𝐦𝐛𝐚𝐬𝐬𝐲 𝐢𝐧 𝐀𝐧𝐭𝐰𝐞𝐫𝐩.

#tdd #unittests #softwaredesign #softwarecrafting

New article: Tales Of TDD - One Test Double To Rule Them All
A short story about the pragmatic use of test doubles.
https://principal-it.eu/2026/03/tdd-tales-one-test-double/

#tdd #testdrivendevelopment #unittests #unittesting #softwaredesign