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verifyLength

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

Verify value has specified length

Syntax

verifyLength(verifiable,actual,expectedLength)
verifyLength(___,diagnostic)

Description

verifyLength(verifiable,actual,expectedLength) verifies that actual is a MATLAB® array whose length is expectedLength.

verifyLength(___,diagnostic) also displays the diagnostic information in diagnostic upon a failure.

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 value to test.

expectedLength

The length of an array is defined as the largest dimension of that 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.

Examples

expand all

Create a TestCase object for interactive testing.

testCase = matlab.unittest.TestCase.forInteractiveUse;

Verify length of array is the expected value, 5.

verifyLength(testCase, ones(2, 5, 3), 5, 'User diagnostic');
Interactive verification passed.

Length of array is not the expected value, 3.

verifyLength(testCase, [2 3], 3);
Interactive verification failed.

---------------------
Framework Diagnostic:
---------------------
verifyLength failed.
--> The array has an incorrect length.
    
    Actual Length:
             2
    Expected Length:
             3

Actual Array:
         2     3

Test failed.

The length of a 2x3 array is 3.

verifyLength(testCase, [1 2 3; 4 5 6], 3);
Interactive verification passed.

Verify the length of a 2x3 array is not the number of elements, 6.

verifyLength(testCase, [1 2 3; 4 5 6], 6);
Interactive verification failed.

---------------------
Framework Diagnostic:
---------------------
verifyLength failed.
--> The array has an incorrect length.
    
    Actual Length:
             3
    Expected Length:
             6

Actual Array:
         1     2     3
         4     5     6

Test failed.

verifyLength(testCase, eye(2), 4);
Interactive verification failed.

---------------------
Framework Diagnostic:
---------------------
verifyLength failed.
--> The array has an incorrect length.
    
    Actual Length:
             2
    Expected Length:
             4

Actual Array:
         1     0
         0     1
testCase = matlab.unittest.TestCase.forInteractiveUse;
verifyLength(testCase, {'someText', 'someotherText'}, 2);
Interactive verification passed.

Tips

  • This method is functionally equivalent to:

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

    There exists more functionality when using the HasLength 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