Periphery
A tool to identify unused code in Swift projects
...If you were to provide all three to the --targets option then Periphery will be able to analyze your project as a whole. However, if you only choose to analyze App and Lib, but not Tests, Periphery may report some instances of unused code that are only referenced by Tests. Therefore when you suspect Periphery has provided an incorrect result, it's important to consider the targets that you have chosen to analyze.