Insert Test Code Using Editor

MATLAB^® lets you create and run test classes interactively. You can create a test class from a template, and then use the code insertion options of the toolstrip to add methods and parameterization properties to the class. You can choose whether to add a method or property at the test level, method-setup level, or class-setup level.

This example shows how to use the MATLAB Editor to write and run a simple parameterized test for a function. To set up the example, define the cleanData function in a file named cleanData.m in your current folder. The function accepts a numeric array and returns a cleaned and sorted version of the array. It vectorizes the array, removes the NaN, 0, and Inf entries, and finally sorts the vector.

function y = cleanData(X)
y = X(:);         % Vectorize the array
y = rmmissing(y); % Remove NaN entries
% Remove 0 and Inf entries
idx = (y == 0 | y == Inf);
y = y(~idx);
% If the vector is empty, set it to eps
if isempty(y)
    y = eps;
end
y = sort(y);      % Sort the vector
end

Create Test Class

To test the cleanData function, create a test class from a template. On the Editor tab, select New > Test Class. Name the class CleanDataTest, and save it in a file named CleanDataTest.m in your current folder.

The template provides a TestClassSetup methods block, a TestMethodSetup methods block, and a Test methods block that defines a simple Test method. The test class in this example requires one test-level parameterization property and two parameterized Test methods. Because it does not require any setup and teardown code, remove the TestClassSetup and TestMethodSetup methods blocks.

classdef CleanDataTest < matlab.unittest.TestCase

    methods (Test)
        % Test methods

        function unimplementedTest(testCase)
            testCase.verifyFail("Unimplemented test");
        end
    end

end

Add Parameters and Methods

Starting in R2022b, when you save or open a test class definition file, the Test section appears on the Editor tab. Use this section to insert code that defines a method or parameterization property:

• To insert code that defines a Test method, click . To access the full list of options, click Insert Method. These options let you add a method at the test level, method-setup level, or class-setup level. You can change the name of the method and implement it after it is inserted.

• To insert code that defines a test-level parameterization property, click . To access the full list of options, click Insert Parameters. These options let you add a property at the test level, method-setup level, or class-setup level. You can change the name and value of the property after it is inserted.

When you insert code for a method or property at the test level, method-setup level, or class-setup level, the code is added to the methods or properties block with the corresponding attribute. If the block does not exist, MATLAB creates it.

Add data Property

To test the cleanData function with different inputs, add a test-level parameterization property to the CleanDataTest class. With the test class code visible in the Editor, go to the Editor tab and in the Test section, click . MATLAB adds a property in a properties block with the TestParameter attribute. Rename the property as data and initialize it using a structure with four fields. The testing framework generates parameter names and values from the property value. For more information about parameterized tests, see Use Parameters in Class-Based Tests.

classdef CleanDataTest < matlab.unittest.TestCase
    
    properties (TestParameter)
        data = struct("empty",[],"scalar",0, ...
            "vector",[13 NaN 0],"matrix",[NaN 2 0; 1 Inf 3]);
    end

    methods (Test)
        % Test methods

        function unimplementedTest(testCase)
            testCase.verifyFail("Unimplemented test");
        end
    end

end

Add sortTest Method

The test class template includes a simple Test method named unimplementedTest. Modify this method to test an aspect of the cleanData function:

1. Rename the method as sortTest.

2. Parameterize the method by passing the data property as the second input argument to the method.

3. Add code to the method to verify that the cleanData function correctly sorts the array passed to it.

classdef CleanDataTest < matlab.unittest.TestCase
    
    properties (TestParameter)
        data = struct("empty",[],"scalar",0, ...
            "vector",[13 NaN 0],"matrix",[NaN 2 0; 1 Inf 3]);
    end

    methods (Test)
        % Test methods

        function sortTest(testCase,data)
            actual = cleanData(data);
            testCase.verifyTrue(issorted(actual))
        end
    end

end

Add nonemptyTest Method

To test if the cleanData function returns a nonempty value, add another Test method to the class by clicking in the Test section. Implement the method by following these steps:

1. Rename the method as nonemptyTest.

2. Parameterize the method by passing the data property as the second input argument to the method.

3. Add code to the method to verify that the cleanData function returns a nonempty value.

Save the file. This code provides the complete contents of the CleanDataTest class.

classdef CleanDataTest < matlab.unittest.TestCase
    
    properties (TestParameter)
        data = struct("empty",[],"scalar",0, ...
            "vector",[13 NaN 0],"matrix",[NaN 2 0; 1 Inf 3]);
    end

    methods (Test)
        % Test methods

        function sortTest(testCase,data)
            actual = cleanData(data);
            testCase.verifyTrue(issorted(actual))
        end
        function nonemptyTest(testCase,data)
            actual = cleanData(data);
            testCase.verifyNotEmpty(actual)
        end
    end

end

Run Tests in Test Class

You can run the tests in the CleanDataTest class interactively in the Editor or in the Test Browser app. For example, with the test class code visible in the Editor, go to the Editor tab and in the Run section, click . In this example, all the tests pass.

For more information on how to run tests and customize your test run interactively, see Run Tests in Editor and Run Tests Using Test Browser.