Skill

Test Driven Development

superpowers

Testing

The discipline of writing a failing test before any production code: watch it fail for the right reason, add just enough code to make it pass, then refactor. It governs the ORDER in which you write code, not which framework runs it - it is a way of working, not a test runner or a coverage tool.

Situations it fits

Your team wants a lightweight rule to make new work safer: write something that forces you to think about the desired behavior before coding changes and keeps your edits tiny and reversible.

Test Driven Development. test-driven-development (superpowers) is the practice that encourages stating expected behavior first and making minimal, incremental changes that can be refactored - helping keep edits small and reversible. The other skills supply tests, data, or browser automation, but TDD is the working habit that shapes how you approach new work.

Your team has a ritual: before adding any feature, they codify the expected behavior as a short executable check, see it fail under CI, then implement the tiniest change to make the check satisfied and clean up the code. Which practice are they following?

Test Driven Development. This describes the workflow of creating an automated verification first, observing it fail, then implementing minimal code to satisfy it and refactor - the core discipline of test-driven development. The other skills generate tests, drive browsers, or produce fixtures, but they don't prescribe the order-of-work habit of writing the check before the production code.

4 scenarios in the bank answer to Test Driven Development. The rest are in the game.

Skills it gets confused with

These share a family with Test Driven Development, which is another way of saying they are the ones you might reach for by mistake.

Knowing what Test Driven Development does is the easy half. Telling it apart from the others under time pressure is the game.

Today's session

Test Driven Development is part of obra/superpowers. Licence: MIT. The description above was written for this game, not taken from the skill.