Einingaprófun

Einingaprófun, or unit testing, is a software testing method where individual units of source code—the smallest testable parts of an application—are isolated and tested to determine whether they are fit for use. A unit is the smallest piece of code that can be logically isolated in a system. In imperative and object-oriented programming, a unit is often a function, a method, or a procedure. In functional programming, it can be a function.

The purpose of unit testing is to validate that each unit of the software performs as designed. This helps to find defects early in the development cycle, making them easier and cheaper to fix. Unit tests are typically written by developers as they write the code they are testing. They are often automated, allowing them to be run frequently.

Key benefits of unit testing include improved code quality, easier debugging, better design, and acting as documentation for the code. When a unit test fails, it indicates a problem that needs to be addressed. By testing small, isolated units, developers can quickly pinpoint the source of errors. Furthermore, well-written unit tests can serve as living documentation, illustrating how individual components are intended to be used and what their expected behavior is. This practice is a fundamental part of modern software development methodologies, including Test-Driven Development (TDD).