Unitary

Unit Testing is a level of software testing where individual units or components of a software are tested. The goal is to validate that each unit functions as intended in isolation from the rest of the code. It helps to catch and fix bugs early in the development cycle, reducing the cost and effort of fixing them later.

Purpose of Unit Testing

• Ensure that individual units or components work correctly in isolation.
• Provide a solid foundation, ensuring code changes don't introduce regressions.
• Improve software design by forcing developers to consider smaller components, thereby making them write more modular and maintainable code.
• Simplify the debugging process. When a test fails, only the latest changes need to be debugged.
• Serve as documentation since unit tests demonstrate how a piece of functionality is supposed to work.

PHP Example using PHPUnit

Let's say we have a simple class Calculator that provides a method to add two numbers: