Does dependency injection have advantages for the process of unit testing code?

Yes, dependency injection significantly simplifies unit testing. Instead of creating real dependencies inside the class or function being tested, you can pass in "stubs" or "mocks". This allows isolating the code under test from external components, controlling the behavior of dependencies, and testing only the logic of the module itself.

For example, if a class depends on a database, during testing you can pass an object that simulates the database, so you don't need to access a real database or depend on its state.