How to use parameterized TestCase

Dear all,

I use the matlab unittest framwork and have the following problem/question. Some of my tests shall access a DUT (device under test) which is connected using TCP. Thus, the tests needs to know the IP Address of the DUT. For me, it is not clear how to solve this issue. I read about ClassSetupParameter and TestClassSetup without success.

One of my test classes looks like:

 classdef A_Tests < matlab.unittest.TestCase
   methods(Test)
     function test_1(testCase)
       (do stuff)
     end
   end
 end

I use a m-file to define my tests like:

 import matlab.unittest.TestRunner;
 import matlab.unittest.TestSuite;
 ...
 dut_ip = '127.0.0.1';
 ...
 A_Suite   = TestSuite.fromClass(?A_Tests);
 B_Suite   = TestSuite.fromClass(?B_Tests);
 RegressionSuite = [A_Suite B_Suite];
 runner        = TestRunner.withTextOutput;
 result = runner.run(RegressionSuite);

The question is how to access the dut_ip variable inside A_Tests, or how to use dut_ip as an parameter for A_Tests.

Thanks a lot in advance.

Best regards, Nico

[Andy Campbell]

Clarifying question. It sounds like you cannot programmatically access this IP address and it must be hardcoded, is that correct?

If you can access it programmatically somehow (perhaps through creating the connection) then you may be able to do something similar to Sean's answer. However, if the IP is purely manual and not accessible programmatically then we will have to go with one of a couple other strategies.

[Nico Falk]

The example above is just as an entry point for discussion. I don't want to hardcode the IP-Addr inside my classdef. But to run the tests at the desired DUT, each test suite (e.g. A-Suite and B-Suite in the example above) needs to know which DUT should be used. The IP-Addr shall be set e.g. in the script I call the "runner.run(RegressionSuite)" command (see example above).

What do you mean with "programmatically access this IP address"?

[Andy Campbell]

 What do you mean with "programmatically access this IP address"?

I was wondering if you make a call to connect to the DUT and it returns the IP address for that connection. Then you could just call that specific function to connect and use the IP from that. Do these IP addresses change frequently? Are they different when the test is run from different machines or environments?

Do you want to run the same suite across many DUTs during the same test run? How are these IP addresses assigned and is there any way to call a function or ask some other piece of software for these IPs?

Do you have an API available to you (or could you make one) to tie a device name to the IP like the following?

ip1 = DeviceIP.getIPFor('device1');
ip2 = DeviceIP.getIPFor('device2');

Answer 1

[Sean de Wolski]

Set it up in a (TestClassSetup) method (so it gets set up before any tests run) and store it as an object property for the remainder of the methods to use. Then close the connection in a (TestClassTeardown) method.

http://www.mathworks.com/help/releases/R2015a/matlab/matlab_prog/write-setup-and-teardown-code-using-classes.html

It's not a parameter in the test case sense where there is an enumerated list of parameters you want to sweep over, it's just a property that the tests need to know about.

Here's a small example:

classdef extcp < matlab.unittest.TestCase

      properties
          Connection
      end

      methods (TestClassSetup)
          function openConnection(testCase)
              testCase.Connection = open(whatever);
          end                  
      end

      methods (TestClassTeardown)
          function closeConnection(testCase)
              close(testCase.Connection)
          end        
      end

      methods (Test)
          function testSomething(testCase)
              use(testCase.Connection)
          end        
      end
  end

[Nico Falk]

Thanks Sean for your quick reply. The documentation listed in your answer describes, how to generate a property or variable which is accessible in all of the tests in this class. There is also an example how to use an environment variable (path) to set up the tests. But I cannot find the solution to set a variable in TestClassSetup with a value defined outside of this scope.

E.g.

 classdef A_Tests < matlab.unittest.TestCase
   properties
     DUT
   end
   methods(TestClassSetup)
     function setup_DUT(testCase)
       testCase.DUT = '127.0.0.1';
     end
   end
   methods(Test)
     function Test_1(testCase)
       testCase.DUT
       testCase.verifyEqual(1, 1, 'Equal');
     end
   end
 end

This gives the following output:

 Running A_Tests
 ans =
 127.0.0.1
 .
 Done A_Tests

Of course, DUT is accessible in all tests. But how to set it to a different value at the beginning of the test?

Thanks, Nico

[Sean de Wolski]

At the beginning of each test or before all tests? If before each test there's also the (TestMethodSetup) attribute.

[Nico Falk]

Before all tests. All tests shall run on the same DUT.