The main characteristics of a unit test are that it should run very quickly and should give consistent results even when executed multiple times with the same set of data. However, to effectively run a unit test and maintain this attribute of having unit tests that are efficients and run quickly, it is important to have mock objects set up where there are dependencies in the code being tested.
For example, in the following code snippet, the LoanRepository class has a dependency on Entity Framework's DbContext class which creates a connection to a database server for database operations. To write a unit test for the GetCarLoans method in the LoanRepository class will necessitate that the DbContext object be constructed. ...