Regarding computer programming, unit testing is a type of software testing where individual components of code, also known as units, undergo testing to validate functionality to ensure the codes perform as expected.
During the coding phase of an application, known as the development phase, a unit of code can be responsible for an individual function, method, procedure, module, or object. It is a “white box testing method” typically performed by the developer, but due to time constraints, it is also often performed by quality assurance (QA) engineers. There are various models of unit testing, including SDLC, STLC, and V Model.