Write Tests Using Shared Fixtures

You can share test fixtures across test classes using the SharedTestFixtures attribute of the matlab.unittest.TestCase class. When you share a fixture across test classes that run together, the testing framework sets up the fixture once for all the test classes and tears it down after all the test classes run. If you specify the fixture using the TestClassSetup methods block of each class instead, the testing framework sets up the fixture before and tears it down after running each test class.

This example shows how to use shared fixtures when creating tests. It shows how to share a fixture for adding a folder containing source code to the path across two test classes. The test classes use this fixture to access the source code required by the tests.

Open the example to make the source and test code available in your current folder.

openExample("matlab/WriteTestsUsingSharedTestFixturesExample")

DocPolynomTest Class Definition

This code shows the contents of the DocPolynomTest class definition file, which uses a shared fixture to access the folder defining the DocPolynom class. For more information about the DocPolynom class and to view the class code, see Representing Polynomials with Classes.

classdef (SharedTestFixtures={ ...
        matlab.unittest.fixtures.PathFixture( ...
        fullfile("..","fixture_example_source"))}) ...
        DocPolynomTest < matlab.unittest.TestCase

    properties
        TextToDisplay = "Equation under test: "
    end

    methods (Test)
        function testConstructor(testCase)
            p = DocPolynom([1 0 1]);
            testCase.verifyClass(p,?DocPolynom)
        end

        function testAddition(testCase)
            p1 = DocPolynom([1 0 1]);
            p2 = DocPolynom([5 2]);
            actual = p1 + p2;
            expected = DocPolynom([1 5 3]);
            diagnostic = [testCase.TextToDisplay ...
                "(x^2 + 1) + (5*x + 2) = x^2 + 5*x + 3"];
            testCase.verifyEqual(actual,expected,diagnostic)
        end

        function testMultiplication(testCase)
            p1 = DocPolynom([1 0 3]);
            p2 = DocPolynom([5 2]);
            actual = p1 * p2;
            expected = DocPolynom([5 2 15 6]);
            diagnostic = [testCase.TextToDisplay ...
                "(x^2 + 3) * (5*x + 2) = 5*x^3 + 2*x^2 + 15*x + 6"];
            testCase.verifyEqual(actual,expected,diagnostic)
        end
    end
end

BankAccountTest Class Definition

This code shows the contents of the BankAccountTest class definition file, which uses a shared fixture to access the folder defining the BankAccount class. For more information about the BankAccount class and to view the class code, see Developing Classes That Work Together.

classdef (SharedTestFixtures={ ...
        matlab.unittest.fixtures.PathFixture( ...
        fullfile("..","fixture_example_source"))}) ...
        BankAccountTest < matlab.unittest.TestCase

    methods (Test)
        function testConstructor(testCase)
            b = BankAccount(1234,100);
            testCase.verifyEqual(b.AccountNumber,1234, ...
                "Constructor must correctly set account number.")
            testCase.verifyEqual(b.AccountBalance,100, ...
                "Constructor must correctly set account balance.")
        end

        function testConstructorNotEnoughInputs(testCase)
            import matlab.unittest.constraints.Throws
            testCase.verifyThat(@()BankAccount,Throws("MATLAB:minrhs"))
        end

        function testDeposit(testCase)
            b = BankAccount(1234,100);
            b.deposit(25)
            testCase.verifyEqual(b.AccountBalance,125)
        end

        function testWithdraw(testCase)
            b = BankAccount(1234,100);
            b.withdraw(25)
            testCase.verifyEqual(b.AccountBalance,75)
        end

        function testNotifyInsufficientFunds(testCase)
            callbackExecuted = false;
            function testCallback(~,~)
                callbackExecuted = true;
            end

            b = BankAccount(1234, 100);
            b.addlistener("InsufficientFunds",@testCallback);

            b.withdraw(50)
            testCase.assertFalse(callbackExecuted, ...
                "The callback should not have executed yet.")
            b.withdraw(60)
            testCase.verifyTrue(callbackExecuted, ...
                "The listener callback should have fired.")
        end
    end
end

Run the Tests

Run the tests in your current folder and its subfolders. The testing framework sets up the shared test fixture, runs the tests in the BankAccountTest and DocPolynomTest classes, and tears down the fixture after running the tests. In this example, all of the tests pass.

runtests("IncludeSubfolders",true);

Setting up PathFixture
Done setting up PathFixture: Added 'C:\work\WriteTestsUsingSharedTestFixturesExample\fixture_example_source' to the path.
__________

Running BankAccountTest
.....
Done BankAccountTest
__________

Running DocPolynomTest
...
Done DocPolynomTest
__________

Tearing down PathFixture
Done tearing down PathFixture: Restored the path to its original state.
__________