matlab.unittest.constraints.HasElementCount class

Package: matlab.unittest.constraints
Superclasses: matlab.unittest.constraints.BooleanConstraint

Constraint specifying expected number of elements

Construction

HasElementCount(countVal) provides a constraint that specifies an expected number of elements. The constraint is satisfied if the actual value array has the same number of elements specified as by countVal.

Input Arguments

countVal

Number of elements a value must have to satisfy the constraint.

Properties

Count

Number of elements a value must have to satisfy the constraint. Set this property through the constructor via the countVal input argument.

Copy Semantics

Value. To learn how value classes affect copy operations, see Copying Objects.

Examples

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Test for Expected Number of Elements

Create a test case for interactive testing.

import matlab.unittest.TestCase
import matlab.unittest.constraints.HasElementCount

testCase = TestCase.forInteractiveUse;

Verify a scalar has an element count of one.

testCase.verifyThat(3, HasElementCount(1))

Interactive verification passed.

Test the element count of the vector.

testCase.assertThat([42 7 13], HasElementCount(3))

Interactive assertion passed.

Test the element count of the matrix.

testCase.assertThat([1 2 3; 4 5 6], HasElementCount(5))

Interactive assertion failed.

---------------------
Framework Diagnostic:
---------------------
HasElementCount failed.
--> The value did not have the correct number of elements.
    
    Actual Number of Elements:
             6
    Expected Number of Elements:
             5

Actual Value:
         1     2     3
         4     5     6
Assertion failed.

The matrix has six elements.

Test that a square identity matrix has the correct number of elements.

n = 7;
testCase.assumeThat(eye(n), HasElementCount(n^2))

Interactive assumption passed.

Verify the element count of a cell array of character vectors.

testCase.verifyThat({'someText', 'moreText'}, HasElementCount(2))

Interactive verification passed.

Test the element count of a structure.

s.Field1 = 1;
s.Field2 = 2;
testCase.verifyThat(s, HasElementCount(2))

Interactive verification failed.

---------------------
Framework Diagnostic:
---------------------
HasElementCount failed.
--> The value did not have the correct number of elements.
    
    Actual Number of Elements:
             1
    Expected Number of Elements:
             2

Actual Value:
        Field1: 1
        Field2: 2

The structure has two fields, but it only has one element.

testCase.verifyThat(s, HasElementCount(1))

Interactive verification passed.

Documentation