Holding a Value in Unit tests

Question

I have a Question for you guys.I have 2 unit tests which are calling webservices .The value that one unit-test returns should be used for another unit test method

Example

namespace TestProject1
{
    public class UnitTest1
    {
        String TID = string.empty;

        public void test1
        {
           //calling webservices and code

           Assert.AreNotEqual(HoID, hID);
           TID = hID;
        }

        public void test2
        {
           //calling webservices and code            
           string HID = TID  // I need the TID value from the Above testcase here

           Assert.AreNotEqual(HID, hID);            
        }
    }
}

How can i store a value in one unittest and use that value in another unittest.

Answer 1

In general, you shouldn't write your tests like this. You cannot ensure that your tests will run in any particular order, so there's no nice way to do this.

Instead make the tests independent, but refactor the common part into it's own (non-test) method that you can call as part of your other test.

Answer 2

Don't reuse any values. Order in which tests are run is very often random (most common runners like NUnit's and Resharper's run tests in random order, some might even do so in parallel). Instead, simply call web service again (even if that means having 2 web service calls) in your second test and retrieve the value you need.

Each test (whether it's unit or integration) should have all the data/dependencies available for it to run. You should never rely on other tests to setup environment/data as that's not what they're written for.

Think of your tests in isolation - each single test is a separate being, that sets up, executes, and cleans up all that is necessary to exercise particular scenario.

Answer 3

Here's an example, following the outlines of Oleksi, of how you could organize this

String TID = string.empty;

[TestFixtureSetUp]
public void Given() {
  //calling webservices and code
  TID = hID;
  //calling webservices and code
}

[Test]
public void assertions_call_1() {
   ...
}

public void assertions_on_call_2() {
   if (string.IsNullOrEmpty(TID))
     Assert.Inconclusive("Prerequisites for test not met");
   ...
}