Assign value to property of mock object when method is called

Hi, is there a way to assign a value to a property of a mock object when a method of the same object is called?

Let's say I create the following mock:

[mock, behavior] = createMock('AddedMethods', "doSomething", 'AddedProperties', "propA");

Now I would like to do something like:

when(withAnyInputs(behavior.doSomething), set(mock.propA, true));

Obviously, that's no valid code, but I think you get what I mean. Thanks for your help!

[Houman Rastegarfar]

Hi Ralf,

You can set the mock object property to the value returned by the mock object method. To achieve this, specify separate behaviors for the method and the property. You can specify one behavior at a time.

import matlab.mock.actions.*
 
testCase = matlab.mock.TestCase.forInteractiveUse;
[mock,behavior] = testCase.createMock('AddedMethods',"doSomething",'AddedProperties',"propA");
 
%Set up behavior when the method is called
when(withAnyInputs(behavior.doSomething),AssignOutputs(true))
 
%Set up behavior when the property is set
when(set(behavior.propA),StoreValue)
 
% Invoke the method and set the property
mock.propA = mock.doSomething

For more information about mock object behavior, see Specify Mock Object Behavior.

-Houman

[Ralf Ritter]

Hi Houman,

Thank you for your suggestions. However, this is not the behavior I wanted to achieve. If I understand correctly, I would still have to manually assign the value to the property as in your last line:

% Invoke the method and set the property
mock.propA = mock.doSomething

I could also do this by simply assigning the value directly to the property:

mock.propA = true;

But I would like the mocking framework to do this by itself, whenever the doSomething method of the mock object is called by the class under test.

To give an example, the class definition of the mocked object could look like this:

classdef ClassA < handle
    
    properties (SetAccess = private)
        propA logical = false        
    end
    
    methods 
        function obj = ClassA
        end
        
        function doSomething(obj)
            % Some code
            if someConditionIsTrue
                obj.propA = true; 
            end
        end
    end
end

Cheers

Ralf

Answer 1

[David Hruska]

If you're using R2018b or later, you can use the Invoke action to set this up. Here's an example:

function example
    import matlab.mock.actions.Invoke;
    testCase = matlab.mock.TestCase.forInteractiveUse;
    [mock, behavior] = testCase.createMock('AddedMethods', "doSomething", 'AddedProperties', "propA");
    when(withAnyInputs(behavior.doSomething), Invoke(@setPropA));
    function obj = setPropA(obj)
        obj.propA = true;
    end
    mock = mock.doSomething;
    disp(mock);
end

[Ralf Ritter]

Thanks a lot for your help!