Where to Draw the Line Between Unit Tests and Integration Tests (archived 2026-09-01)

We organize the boundary between unit tests and integration tests along the axes of pure logic, formats, wiring, environment differences, and time dependence, and condense it into a decision table you can use without hesitation in practice. Archived version of https://comcomponent.com/en/blog/2026/03/25/004-unit-test-vs-integration-test-boundary-guide/, as published on 2026-09-01. The live article is maintained and may change after this date. First published 2026-03-25.