unit test
compound.compound. a small check that a programmer writes to make sure one specific part of their code works correctly. It focuses on the smallest possible piece of the program to find bugs early.
compound. a procedure used to validate that an individual component or 'unit' of software performs as designed. Typically automated, these checks isolate a specific function or method to ensure its logic remains sound after changes.
I need to write a unit test for this new login function.
The developer ran the entire suite of unit tests to ensure that the recent bug fix didn't break any existing features.
Comprehensive unit tests are a cornerstone of test-driven development, allowing engineers to refactor complex codebases with the confidence that the fundamental logic of each module remains intact.
A compound of unit, denoting a single entity or individual part, and test, from the Middle English term for a vessel used to assay precious metals. The phrase emerged from general engineering practices where discrete components are verified independently before assembly.
Etymology adapted from Wiktionary, available under CC BY-SA 4.0.
Commonly used in the plural ('unit tests') when referring to a collection of checks for a project.
Last updated July 22, 2026