When to use stubs and mocks?

Question

I\'ve this confusion all the time. If I write a code which uses fake code to assert some operation, how do i trust my real implementation when it is started really using the

Answer 1

Most kinds of unit testing is about testing individual pieces of code, and stubs and mocks are simply tools that assist you in testing piece-by-piece. By testing pieces individually you can probably test each piece in greater detail, but you will not be guaranteed anything about the full picture. Various kinds of integration testing will do that.

When testing bigger pieces of functionality, I often find actual integration tests of database logic to be the least valuable test artifacts, since you will often be testing these same operations at the UI level.