Software Architect's Handbook

Refactoring for unit tests

The application may not have been designed to be unit-testable. Ideally, unit tests would be in place prior to performing any refactoring work. However, as a software architect, you may be faced with a dilemma if you need to refactor an application just so you can write unit tests.

When faced with a situation in which automated unit tests do not already exist, some initial refactoring may be necessary, just to allow for the creation of the initial set of tests. From that point, further refactoring and the addition of more unit tests will be possible.

Another approach for this situation is to write integration tests. Integration tests can then be executed before any refactoring changes to confirm that the original ...