Chapter 17

1. Unit testing is a type of software testing where individual units of code are tested in order to validate whether they are working as they were designed to work. Unit testing helps to identify and fix bugs early in the development cycle, therefore helping to save time and money. It helps developers to better understand the code and allows them to make changes easier. It helps with code reuse by requiring the code to be more modular in order to test it better. It can act as project documentation. It also helps with debugging because when tests fail, only the latest changes need to be checked and debugged.
2. Visual Studio tools for unit testing are the Test Explorer (where you can view, run, debug, and analyze tests), the Microsoft unit testing framework for managed code, code coverage tools (which determine the amount of code that unit tests are covering), and the Microsoft Fakes isolation framework (which allows you to create substitutes for classes and methods).
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