Using dependencies mocking, you technically create alternatives to the dependencies in your code that you can experiment with. When you have a mock implementation of dependencies in place, you can make changes and test the effect of the changes in isolation since the tests will be running against mock objects and not the real objects.
When you have the dependencies isolated, you can focus on the test being run, thereby limiting the scope of your test to the code that really matters for the test. In essence, with the reduced scope, you can easily refactor the code being tested as well as the test itself, giving you a clear picture of areas where the code can be improved.
In order to test the LoanRepository class in the ...
