What is the expected outcome of unit testing?

Unit testing primarily focuses on verifying the individual components or modules of a software application in isolation from the rest of the software system. The expected outcome is to identify defects within these isolated units, ensuring that each piece of code functions correctly according to its specifications. By isolating individual modules, developers can pinpoint the exact source of any issues, making it easier to correct defects early in the development process.

While measuring user satisfaction, checking software compatibility, and improving security features are all important aspects of software quality assurance, they extend beyond the scope of unit testing. User satisfaction typically involves usability testing and feedback mechanisms which assess the user experience as a whole. Software compatibility testing ensures that the application works across different environments, platforms, or systems, which comes later in the testing lifecycle. Enhancing security features is usually tackled through specific security testing approaches, which focus on potential vulnerabilities rather than the functionality of individual units. Thus, the primary and most relevant expected outcome of unit testing is the identification of defects in isolated modules.