# Saturday, June 30, 2007

In Pex, we added the possibility to specify the type under test of a given fixture:

public class Account {...}

[TestFixture, PexClass(typeof(Account))]
public class AccountTest {...}  

That's nice but why would it be useful... Beyond the fact that it clearly expresses the 'target' of the fixture, this kind of information can be leverage by tools like Pex.

For example, since we know that Account is the type under test, we can tune Pex to prioritize the exploration of the Account type.

Another interesting side effect is the targeted code coverage data. Instead of getting coverage information over the entire assembly, we can directly provide coverage over the type under test: the AccountTest covered xx% of Account.

Still toying around the concept, one can add a special filtering mode to the command line to execute all tests that target 'Account':

pex.exe /type-under-test:Account Bank.Tests.dll
posted on Saturday, June 30, 2007 12:23:24 AM (Pacific Daylight Time, UTC-07:00)  #    Comments [0]
# Saturday, June 02, 2007

A nice side effect of the Pex infrastructure is that it computes coverage data while exploring a parameterized test. What does this mean to the user? Well, what about this specifying that a parameterized test should reach 100% coverage**:

[PexExpectedCoverage(100)] // expect 100% coverage
public void UberTest(int i)
{ ... }
** What kind of coverage are we talking about?

Pex internally tracks implicit branch coverage (which can never be covered :)). So we usually refer to basic block coverage. By default, the coverage is reported for the code that was run by the parameterized test. This is a very important difference with usual coverage tools, which give numbers for the entire assembly.

posted on Saturday, June 02, 2007 10:24:56 PM (Pacific Daylight Time, UTC-07:00)  #    Comments [0]