What proportion of code in the project is covered by automated tests?

The optimal code coverage share with automated tests depends on the project and requirements, but generally aims for around 70-80% coverage.

It's important not just the quantity, but the quality of tests: they should cover critical business logic, main scenarios, and potential errors.

Too low coverage increases the risk of bugs, while too high may lead to excessive costs for maintaining tests.

In C#, tools like Visual Studio Code Coverage, dotCover, or OpenCover are often used to measure coverage.