Why Xcode 7 shows around 12% code coverage when there are no unit tests at all?

Question

I am working on a project in Xcode for iOS app and I enabled "Gather coverage data" in the "Edit scheme -> Test".

I also created a test target with an empty unit test, the only one in the whole project so far and now when I run the test I can see that around 12% of code has been covered (The project has around 500 files in the project and there are many classes in the coverage report that are displayed as covered).

How is this possible? Did I miss something?

In wiki there is "In computer science, code coverage is a measure used to describe the degree to which the source code of a program is tested by a particular test suite." We have only one test suite and it is empty.

Answer 1

As of Xcode 8, running the tests actually instantiates the app. That means that all the initialization code is executed. This will show as covered code in the test coverage report.