Software Development Cross Solution - Index of - Free

system testing vs. unit testing
#4. System tests vs. unit tests
In chapters 7 and 8, you learned how to build testing and continuous integration
into your development process. Testing is one of the key tools you have to prove that
your code works and meets the requirements set by your customer. These two
different goals are supported by two different types of tests.
440 Appendix i
Unit tests test your CODE
Unit tests are used to test that your code does what it should. These are the
tests that you build right into your continuous build and integration cycle, to
make sure that any changes that you make to code don’t break these tests, on
your code and the rest of the code base.
Ideally, every class in your software should have an associated unit test. In fact,
with test-driven development, your tests are developed before any code is even
written, so there is no code without a test. Unit tests have their limits, though.
For example, maybe you make sure that calling drive() on the Automobile
class works... but what happens when other instances of Automobile are also
driving, and using the same RaceTrack object, too?
System tests test your SOFTWARE
System tests pick up where unit tests leave off. A system test tests your
code when it is integrated into a fully functional system. System
tests are sometimes automated, but often involve someone actually
exercising your entire system in very much the same way as the end
user will.
For example, you might fire up the GUI for monitoring a race, press the
“Start Race” button, watch animated versions of cars spin around the track,
and then initiate a wreck. Does everything work the way the customer
expects? That’s a system test.
Q: In addition to unit and system tests, aren’t
there lots of other types of tests as well?
A: Yes. Testing is a BIG field of work. There are
various names for testing, conducted at anything from
the source code level to enterprise software integration
level. For example, you may hear of acceptance tests.
Acceptance tests are often conducted with the customer,
where the customer either accepts or rejects your
software as doing what they need..
Download at WoweBook.Com
Unit testing is at a very
low level... source files
and XML descriptors.
System testing looks
at your application
as a whole.
Unit tests prove that
your code WORKS.
System tests prove that
your software meets its
REQUIREMENTS.