Professional Scrum Master (PSM) III Practice Test

Code coverage is a metric that measures the percentage of source code that is tested by a set of tests. However, it has notable shortcomings that can mislead teams about the effectiveness of their testing efforts.

The option chosen highlights that code coverage does not guarantee that critical parts of the code, particularly those that pose the greatest risk or are most important to the application's functionality, are being effectively tested. It is possible for a project to achieve a high percentage of code coverage while neglecting testing of risky areas. This means that while a lot of the code is executed during tests, those tests may not validate that the code behaves as expected in crucial scenarios, which could result in undetected defects in high-risk areas.

In addition to this, other limitations of code coverage include the possibility of creating a false sense of security regarding how well an application has been tested. For instance, the coverage metric can be manipulated by writing superficial tests that do not contribute to meaningful validation of the system's behavior. This can lead teams to focus excessively on increasing coverage statistics rather than the quality and effectiveness of their tests. Such behavior can detract from the main goal of testing, which is to ensure the software meets user needs and functions correctly.