Pass parameter to class based unit test

I have written matlab code to interface with a hardware device through tcp/ip.

I have written a class based testcase for it, but I would like to be able to select the ip-address where the device is residing whenever I want to run my tests. I also want to be able to selectively run tests from my testcase class. To do this, I want to be able to create a testsuite from the testcase, and only run selected indices from the generated testsuite array.

To be able to specify the ip-address, I added a constructor parameter to my test case to set a property, which is then used to open the device at the correct location. This works fine to run the complete testcase without explicit testsuite, but I cannot generate a testsuite from it.

Is there a way to do this more elegantly, giving me the options to pass the parameter when I want to test, and still have control over which tests I want to run ?

(Note that this has nothing to do with parametric testing)

Concept code for the testcase definition:

% My testcase definition
classdef tc <  matlab.unittest.TestCase
    properties
        host_;  % Ip address of the device
    end
   
     methods
        % constructor to allow specifying correct address
        function self = tc(host)
            self.host_ = host;
        end
    end
    
    % test fixtures and test methods using self.host_ to open device   
end

This allows to run the full testcase specifying the host parameter, giving me test results for the 72 (parametric) tests in the testcase class

run(tc('192.168.1.5')) % run all tests with the device at this ip-address

I can create a testsuite from the class, but when I run tests from the suite it will throw an error because the testcase constructor argument is missing.

suite = matlab.unittest.TestSuite.fromClass(?tc)
run(suite(1)) % causes missing input argument error

Is there a way to create the testsuite from a class object rather than from the class, so that I can specify the constructor argument and still have control over which exact tests I want to run.

Answer 1

[Steven Lord]

Rather than giving your test class a constructor I'd specify the parameter as a ClassSetupParameter (with some reasonable default) and use the capability to specify an external parameter value.

classdef test1673009 < matlab.unittest.TestCase
    properties(ClassSetupParameter)
        identifier = struct('id', 1);
    end
    
    methods(TestClassSetup)
        function reportID(~, identifier)
            fprintf("Running test with ID %d\n", identifier);
        end
    end
    
    methods(Test)
        function basicTestCase(testcase, identifier)
            testcase.verifyGreaterThan(identifier, 0);
        end
    end
end

If I run the test without specifying a value for the parameter it uses the default given in the test.

>> suite = matlab.unittest.TestSuite.fromClass(?test1673009);
>> run(suite)
Running test1673009
Running test with ID 1
.
Done test1673009

But I can inject a parameter when I create the suite.

>> newparam = struct('id', 12345);
>> P = matlab.unittest.parameters.Parameter.fromData('identifier', newparam);
>> suite = matlab.unittest.TestSuite.fromClass(?test1673009, ...
    'ExternalParameters', P);
>> run(suite)
Running test1673009
Running test with ID 12345
.
Done test1673009

[goc3]

This was a helpful example. Thanks, Steven!