matlab.unittest.plugins.FailOnWarningsPlugin - Plugin that fails tests that issue warnings - MATLAB (original) (raw)

Main Content

Namespace: matlab.unittest.plugins
Superclasses: matlab.unittest.plugins.QualifyingPlugin, matlab.unittest.plugins.TestRunnerPlugin, matlab.unittest.plugins.Parallelizable

Plugin that fails tests that issue warnings

Description

The matlab.unittest.plugins.FailOnWarningsPlugin class provides a plugin that fails any test that issues a warning. The plugin produces a qualification failure in the test scope that issues the warning. For example, if a shared test fixture issues a warning, the plugin produces a qualification failure on the fixture and fails all tests that share the fixture.

The plugin does not produce a failure if:

A test accounts for the warning through a constraint such as IssuesWarnings or IssuesNoWarnings, regardless of whether the constraint is satisfied.
The warning is disabled, for example, using the SuppressedWarningsFixture class.
The plugin is explicitly instructed to ignore the warning.

The matlab.unittest.plugins.FailOnWarningsPlugin class is a handle class.

Creation

Description

plugin = matlab.unittest.plugins.FailOnWarningsPlugin creates a plugin that fails any test that issues a warning.

example

plugin = matlab.unittest.plugins.FailOnWarningsPlugin(Ignoring=[identifiers](#mw%5Fe084c91d-ea1b-457a-9c26-f8990090532c)) ignores warnings with the specified identifiers. For example, plugin = matlab.unittest.plugins.FailOnWarningsPlugin(Ignoring="MATLAB:singularMatrix") creates a plugin that does not fail tests because of the specified warning.

Input Arguments

expand all

Warning identifiers to ignore, specified as a string array or cell array of character vectors. The plugin does not fail tests because of the specified warnings.

This argument sets the Ignore property.

Example: "MATLAB:MKDIR:DirectoryExists"

Example: {'MyComponent:FirstID','MyComponent:SecondID'}

Properties

expand all

Warning identifiers to ignore, specified as a string array or cell array of character vectors, and stored as a cell array of character vectors. By default, the value is an empty cell array.

This property is set by the identifiers input argument.

Attributes:

GetAccess	public
SetAccess	private

Examples

collapse all

Fail any test that issues a warning by using theFailOnWarningsPlugin class.

In a file named solver.m in your current folder, create thesolver function to solve a system of linear equations. The function includes an intentional bug—the assert call that checks whether a matrix is well conditioned should use rcond instead of det.

function x = solver(A,b) assert(abs(det(A)) > 1e-12, ... % Intentional bug for illustrative purposes "The matrix is singular or nearly singular.") x = A\b; end

To test the solver function, create theSolverTest test class in a file named SolverTest.m in your current folder. In the testTwo method, A is a singular matrix. The solver function does not notice the singularity due to the bug in the assert call and causes the test to issue a warning.

classdef SolverTest < matlab.unittest.TestCase methods (Test) function testOne(testCase) A = eye(3); b = [3; 4; 1]; testCase.verifyEqual(solver(A,b),b) end

    function testTwo(testCase)
        A = [1e-100 0; 0 1e100];
        b = [5; 5];
        expected = [5e100; 5e-100];
        testCase.verifyEqual(solver(A,b),expected)
    end
end

end

Import the FailOnWarningsPlugin class.

import matlab.unittest.plugins.FailOnWarningsPlugin

Create a test suite from the test class.

suite = testsuite("SolverTest");

Run the tests using a FailOnWarningsPlugin instance. The plugin fails the second test because it issues a warning. Without the plugin, the test passes.

runner = testrunner("textoutput"); plugin = FailOnWarningsPlugin; runner.addPlugin(plugin) results = runner.run(suite);

Running SolverTest .Warning: Matrix is close to singular or badly scaled. Results may be inaccurate. RCOND = 1.000000e-200. ... .

Verification failed in SolverTest/testTwo. --------------------- Framework Diagnostic: --------------------- SolverTest/testTwo issued warnings:

--------------------------- MATLAB:nearlySingularMatrix --------------------------- Matrix is close to singular or badly scaled. Results may be inaccurate. RCOND = 1.000000e-200. In C:\work\solver.m (solver) at 4 In C:\work\SolverTest.m (SolverTest.testTwo) at 13 ------------------ Stack Information: ------------------ In C:\Program Files\MATLAB\R2024b\toolbox\matlab\testframework\unittest\core+matlab+unittest+plugins\FailOnWarningsPlugin.m (FailOnWarningsPlugin.teardownTestMethod) at 178

Done SolverTest

Failure Summary:

 Name                Failed  Incomplete  Reason(s)
=================================================================
 SolverTest/testTwo    X                 Failed by verification.

Tips

To set the warning stack trace display, use the warning function. For example, warning("off","backtrace") disables display of the stack trace.
To suppress the display of warnings when testing, use the matlab.unittest.fixtures.SuppressedWarningsFixture class.

Version History

Introduced in R2015b