Introduction

You might be wondering what code contracts are exactly. To explain it in layman's terms, a code contract is a definition that you add to your methods. It tells the compilers that the method under contract will always adhere to specific conditions. An example of this is that the method will never return a null value to the calling code or that the method will always expect a parameter greater than a specific value. If any of these conditions are not met, your code can emit an exception, and the developer integrating with your class will be prompted to refine their calling code. On the flip side, when a developer calls your class, they can be sure that the method under contract will always behave in a specific way and never deviate from it.

Code contracts really stand out when working within a team of developers, but implementing this technology in a single-developer solution will only improve your code.