Test Class Definition

To write class-based tests, first create a class that derives from the matlab.unittest.TestCase class. Then, specify your unit tests by adding methods to a methods block with the Test attribute within your test class. For example, the MyTestClass class includes two tests (test1 and test2). The first input to a Test method must be a TestCase object, which the test can ignore if its logic does not require it. The TestCase object passed to a Test method provides test-environment-specific information to the corresponding test.

In addition, the MyTestClass class uses framework-specific method attributes to define the setup and teardown methods. The testing framework runs these methods before and after each test, respectively. For more information about setup and teardown code in test classes, see Write Setup and Teardown Code Using Classes.

classdef MyTestClass < matlab.unittest.TestCase
    methods (TestMethodSetup)
        function setup(testCase)
            % Setup code
        end
    end

    methods (TestMethodTeardown)
        function teardown(testCase)
            % Teardown code
        end
    end

    methods (Test)
        function test1(testCase)
            % Test code
        end

        function test2(testCase)
            % Test code
        end
    end
end

Unit tests typically include qualifications for testing values and responding to failures. For example, to test a function, a Test method can specify the actual and expected returned values of the function and then use a qualification method to test for their equality. For illustrative purposes, the PlusTest test class has a Test method for testing the plus function. (In practice, a test class tests user-defined code.) The myTest method calls the verifyEqual qualification method to verify that plus(2,3) produces the expected value 5. When creating your own test class, you have access to the full library of qualifications in the matlab.unittest.qualifications namespace. To determine which qualification to use, see Table of Verifications, Assertions, and Other Qualifications.

classdef PlusTest < matlab.unittest.TestCase
    methods (Test)
        function myTest(testCase)
            actual = plus(2,3);
            expected = 5;
            testCase.verifyEqual(actual,expected)
        end
    end
end

For a simple example of how to write and run class-based unit tests, see Write Simple Test Case Using Classes.

How Test Classes Run

When you run class-based tests (for instance, results = runtests(["TestClassA" "TestClassB" "TestClassC"])), the testing framework first divides the test classes into groups based on their shared test fixtures. (Shared test fixtures are fixtures specified using the SharedTestFixtures attribute of TestCase subclasses.) Each group includes test classes that have exactly the same shared test fixtures. To minimize the required setup and teardown actions, the framework runs the test classes in each group by setting up and tearing down their shared test fixtures a single time. In other words, for each group, the framework:

This diagram shows how the testing framework runs each test class in step 2.

The framework follows these steps when running a test class:

Test Independence and Repeatability

Unit tests in a matlab.unittest.TestCase subclass must run independently, without unintentionally affecting one another. In addition, they must be repeatable, which means that a running test must not affect subsequent reruns of the same test. For test independence and repeatability, follow these best practices when creating a test class:

For more information, see Write Independent and Repeatable Tests.

Features of Class-Based Tests

Class-based tests provide you with several advanced test authoring features and give you access to the full MATLAB unit testing framework functionality. For example, you can use advanced qualification features, including constraints, actual value proxies, tolerances, and test diagnostics, in your class-based tests. In addition, with class-based tests, you can: