Main Content

verifyWarning

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

Verify function issues specified warnings

Syntax

verifyWarning(verifiable,actual,warningIDs)
verifyWarning(verifiable,actual,warningIDs,diagnostic)
[output1,...,outputN] = verifyWarning(___)

Description

verifyWarning(verifiable,actual,warningIDs) verifies that actual issues warnings with the identifiers warningIDs.

verifyWarning(verifiable,actual,warningIDs,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] = verifyWarning(___) also returns the output arguments output1,...,outputN that are produced when invoking actual.

Input Arguments

verifiable

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

actual

The function handle to test.

warningIDs

Warning identifiers, specified as a character vector, cell array of character vectors, or string array.

diagnostic

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

output1,...,outputN

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

Examples

expand all

Create a TestCase object for interactive testing.

testCase = matlab.unittest.TestCase.forInteractiveUse;

Verify that actual warning identifier is the same as input warning identifier.

verifyWarning(testCase, @() warning('SOME:warning:id', 'Warning!'), ...
    'SOME:warning:id');
Verification passed.
verifyWarning(testCase, @() warning('SOME:other:id', 'Warning message'), ...
    'SOME:warning:id', 'Did not issue specified warning');
Warning: Warning message 
> In @()warning('SOME:other:id','Warning message')
  In matlab.unittest.internal.constraints/FunctionHandleConstraint/invoke (line 35)
  In matlab.unittest.internal.constraints/WarningQualificationConstraint/invoke (line 41)
  In matlab.unittest.constraints/IssuesWarnings/invoke (line 429)
  In matlab.unittest.constraints.IssuesWarnings>@()constraint.invoke(fcn) (line 540)
  In matlab.unittest.internal.fevalcRespectingHotlinks/hotwrap (line 18)
  In matlab.unittest.internal.fevalcRespectingHotlinks (line 14)
  In matlab.unittest.constraints/IssuesWarnings/invokeCapturingOutput (line 540)
  In matlab.unittest.constraints/IssuesWarnings/issuesExpectedWarnings (line 549)
  In matlab.unittest.constraints/IssuesWarnings/satisfiedBy (line 239)
  In matlab.unittest.internal.constraints/CasualDiagnosticDecorator/satisfiedBy (line 42)
  In matlab.unittest.internal.qualifications/QualificationDelegate/qualifyThat (line 79)
  In matlab.unittest.internal.qualifications/QualificationDelegate/qualifyWarning (line 200)
  In matlab.unittest.qualifications/Verifiable/verifyWarning (line 757) 
Verification failed.
    ----------------
    Test Diagnostic:
    ----------------
    Did not issue specified warning
    ---------------------
    Framework Diagnostic:
    ---------------------
    verifyWarning failed.
    --> The function handle did not issue the expected warning(s).
        
        Actual Warning(s):
            --> 'SOME:other:id'
        Expected Warning(s):
            --> 'SOME:warning:id'
    
    Evaluated Function:
      function_handle with value:
    
        @()warning('SOME:other:id','Warning message')

Test the true function, which does not issue warnings.

testCase = matlab.unittest.TestCase.forInteractiveUse;
verifyWarning(testCase, @true, 'SOME:warning:id', ...
'@true did not issue any warning');
Verification failed.
    ----------------
    Test Diagnostic:
    ----------------
    @true did not issue any warning
    ---------------------
    Framework Diagnostic:
    ---------------------
    verifyWarning failed.
    --> The function handle did not issue any warnings.
        
        Expected Warning(s):
            --> 'SOME:warning:id'
    
    Evaluated Function:
      function_handle with value:
    
        @true

Test failed.

Create a helper function that generates a warning and returns output.

function varargout = helper()
    warning('SOME:warning:id', 'Warning!');
    varargout = {123, 'abc'};
end

Call helper.

testCase = matlab.unittest.TestCase.forInteractiveUse;
[actualOut1, actualOut2] = verifyWarning(testCase, @helper, ...
    'SOME:warning:id');
Verification passed.

Tips

  • This method is functionally equivalent to:

    import matlab.unittest.constraints.IssuesWarnings;
    verifiable.verifyThat(actual,IssuesWarnings(cellstr(warningIDs)));
    

    There exists more functionality when using the IssuesWarnings 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