Question

I’m writing many unit tests in VS 2010 with Microsoft Test. In each test class I have many test methods similar to below:

[TestMethod]
public void This_is_a_Test()
{
  try
  {
    // do some test here
    // assert
  }
  catch (Exception ex)
  {
    // test failed, log error message in my log file and make the test fail
  }
  finally
  {
    // do some cleanup with different parameters
  }
}

When each test method looks like this I fell it’s kind of ugly. But so far I haven’t found a good solution to make my test code more clean, especially the cleanup code in the finally block. Could someone here give me some advices on this?

Thanks in advance.

Answer 1

If you really want to handle and log exceptions whilst test execution you can wrap up this standard template in a helper method and use like shown below [*].

But if exceptions is a part of test case this is wrong approach and you should use facilities provided by a test framework, for instance NUnit provides such helpers to test exceptions:

Assert.Throws<ExceptionType>(() => { ... code block... });
Assert.DoesNotThrow(() => { ... code block... });

And to do cleanup special method attributes like [TestCleanup] and [TestInitialize] to do test initialization and cleanup automatically by a test framework.

[*] The idea is to wrap test body in a delegate and pass into the helper which actually perform test execution wrapped in the try/catch block:

// helper
public void ExecuteTest(Action test)
{
  try
  {
     test.Invoke();
  }
  catch (Exception ex)
  {
    // test failed, log error message in my log file and make the test fail
  }
  finally
  {
    // do some cleanup with different parameters
  }
}

[TestMethod]
public void This_is_a_Test_1()
{
   Action test = () =>
   {
       // test case logic
       // asserts
   };

   this.ExecuteTest(test);
}