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Class: matlab.unittest.qualifications.Verifiable
Package: matlab.unittest.qualifications

Verify function issues no warnings


output1,...,outputN = verifyWarningFree(___)


verifyWarningFree(verifiable,actual) verifies that actual is a function handle that issues no warnings.

verifyWarningFree(___,diagnostic) also associates the diagnostic information in diagnostic with the qualification. Depending on the test runner configuration, the testing framework might display diagnostics when the qualification passes or fails. By default, the framework displays diagnostics only when the qualification fails. You can override the default behavior by customizing the test runner. For example, use a DiagnosticsOutputPlugin instance to display both failing and passing event diagnostics.

output1,...,outputN = verifyWarningFree(___) also returns the output arguments output1,...,outputN that are produced when invoking actual.

Input Arguments


The matlab.unittest.TestCase instance which is used to pass or fail the verification in conjunction with the test running framework.


The function handle to test.


Diagnostic information related to the qualification, specified as one of the following:

  • string array

  • character array

  • function handle

  • matlab.unittest.diagnostics.Diagnostic object

Diagnostic values can be nonscalar. For more information, see matlab.unittest.diagnostics.Diagnostic.

Output Arguments


Output arguments, 1 through n (if any), from actual, returned as any type. The argument type is specified by the actual argument list.


expand all

Create a TestCase object for interactive testing.

testCase = matlab.unittest.TestCase.forInteractiveUse;

Test the why function.

verifyWarningFree(testCase, @why);
The bald and not excessively bald and not excessively smart hamster obeyed a terrified and not excessively terrified hamster.
Interactive verification passed.

This is a randomly-generated message.

Test the true function.

verifyWarningFree(testCase, @true);
Interactive verification passed.

Test the false function.

actualOutputFromFalse = verifyWarningFree(testCase, @false);
Interactive verification passed.

Test a value that is not a function handle.

verifyWarningFree(testCase, 5,'diagnostic');
Interactive verification failed.

Test Diagnostic:

Framework Diagnostic:
verifyWarningFree failed.
--> The value must be an instance of the expected type.
    Actual Class:
    Expected Type:

Actual Value:

Test failed.

Test a function that generates warning.

verifyWarningFree(testCase, @() warning('some:id', 'Message'));
Warning: Message 
> In @()warning('some:id','Message')
  In FunctionHandleConstraint>FunctionHandleConstraint.invoke at 43
  In WarningQualificationConstraint>WarningQualificationConstraint.invoke at 58
  In IssuesNoWarnings>IssuesNoWarnings.issuesNoWarnings at 131
  In IssuesNoWarnings>IssuesNoWarnings.satisfiedBy at 82
  In QualificationDelegate>QualificationDelegate.qualifyThat at 90
  In QualificationDelegate>QualificationDelegate.qualifyWarningFree at 204
  In Verifiable>Verifiable.verifyWarningFree at 757 
Interactive verification failed.

Framework Diagnostic:
verifyWarningFree failed.
--> The function issued warnings.
    Warnings Issued:

Evaluated Function:

Test failed.


  • This method is functionally equivalent to:

    import matlab.unittest.constraints.IssuesNoWarnings;
    verifiable.verifyThat(actual, IssuesNoWarnings());

    There exists more functionality when using the IssuesNoWarnings constraint directly via verifyThat.

  • Use verification qualifications to produce and record failures without throwing an exception. Since verifications do not throw exceptions, all test content runs to completion even when verification failures occur. Typically verifications are the primary qualification for a unit test since they typically do not require an early exit from the test. Use other qualification types to test for violation of preconditions or incorrect test setup. Alternatively,

    • Use assumption qualifications to ensure that the test environment meets preconditions that otherwise do not result in a test failure. Assumption failures result in filtered tests, and the testing framework marks the tests as Incomplete. For more information, see matlab.unittest.qualifications.Assumable.

    • Use assertion qualifications when the failure condition invalidates the remainder of the current test content, but does not prevent proper execution of subsequent test methods. A failure at the assertion point renders the current test method as failed and incomplete. For more information, see matlab.unittest.qualifications.Assertable.

    • Use fatal assertion qualifications to abort the test session upon failure. These qualifications are useful when the failure mode is so fundamental that there is no point in continuing testing. These qualifications are also useful when fixture teardown does not restore the MATLAB® state correctly and it is preferable to abort testing and start a fresh session. For more information, see matlab.unittest.qualifications.FatalAssertable.

Introduced in R2013a