Concepts: Unit testing

Short essays on the ideas behind unit testing — the pieces you read once and keep coming back to when something about your test suite surprises you. The "ah, that's why" layer beneath the syntax.

Essays in this section

• Why unit testing — the case for writing tests, and the kinds of bugs they catch (and don't).
• Understanding test structure — Arrange-Act-Assert, what each part is for, and what a well-shaped test reads like.