I am running an NUnit (version 2.5.10) test from GUI runner. I observed that when the test is run with just that single test loaded, it takes a lot less time than when it is run with the entire test suite loaded.
I experimented by commenting all the test case sources used in other tests, that did bring down the time but it is still higher than loading a single test.
My question is why does commenting the other test case sources brings down the time it takes to run the test. I can understand that it will reduce the tests load time, but why would it impact test run time.
Also, is there any other thing that can affect the test performance.
I think I found the problem. One of the unit test was explicitly calling GC.Collect(). This was taking a long time when entire test suite is loaded since there are more objects in memory.