Fast Tests

Fast is not “tests should be quick”; it is the precondition for the tests being run at all. A suite nobody runs protects nothing. Eight independent authorities converge on it, from the FIRST acronym (2008) to Google’s SWE book (2020), with thresholds like a tenth of a second per test (Shore), a thousand tests per second per core (Bazuzi), and about ten minutes for the full suite (Fowler).

Minimal Data and parallel execution are the usual levers. Part of Test Desiderata.

Measuring: per-test wall clock with a CI gate (0.5–1s), and suite wall-clock trend: DORA elite keeps the test job under five minutes.