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matlab.unittest.constraints.BooleanConstraint class

Package: matlab.unittest.constraints
Superclasses: matlab.unittest.constraints.Constraint

Fundamental interface for constraints that support Boolean operations

Description

The matlab.unittest.constraints.BooleanConstraint class provides an interface that you can use to create constraints that can be combined and negated using the and (&), or (|), and not (~) operators.

To create a custom constraint class that supports Boolean operations, derive your class from matlab.unittest.constraints.BooleanConstraint and implement the required abstract methods:

  • Implement the satisfiedBy method to encode the comparison logic. The BooleanConstraint class inherits this method from matlab.unittest.constraints.Constraint.

  • Implement the getDiagnosticFor method to produce diagnostic information when the testing framework evaluates the actual value against the constraint. The BooleanConstraint class inherits this method from the Constraint class.

  • Implement the getNegativeDiagnosticFor method to produce diagnostic information when the framework evaluates the actual value against the negated constraint. When a constraint is negated, the diagnostics must be written in a different form than for the standard (non-negated) usage.

Because the BooleanConstraint class derives from the Constraint class, BooleanConstraint subclasses support the functionality provided by Constraint subclasses. For example, you can use them with the assertThat, assumeThat, fatalAssertThat, and verifyThat qualification methods from the matlab.unittest.qualifications package. Additionally, you can negate a BooleanConstraint object or combine it with other BooleanConstraint objects.

Class Attributes

Abstract
true

For information on class attributes, see Class Attributes.

Methods

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Examples

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Some built-in constraints, such as HasElementCount and HasLength, are subclasses of BooleanConstraint. You can combine and negate these constraints in your tests.

First, import the classes used in this example.

import matlab.unittest.TestCase
import matlab.unittest.constraints.HasElementCount
import matlab.unittest.constraints.HasLength
import matlab.unittest.constraints.HasInf
import matlab.unittest.constraints.HasNaN
import matlab.unittest.constraints.IsEqualTo
import matlab.unittest.constraints.IsGreaterThanOrEqualTo
import matlab.unittest.constraints.IsReal

Create a test case for interactive testing.

testCase = TestCase.forInteractiveUse;

Verify that the value 3 is real and that it is greater than or equal to 3.

testCase.verifyThat(3,IsReal & IsGreaterThanOrEqualTo(3))
Verification passed.

Verify that the value 3 is not equal to 4.

testCase.verifyThat(3,~IsEqualTo(4))
Verification passed.

Test if the matrix [1 2 3; 4 5 6] has a length of six or has six elements. The test passes because one of the or conditions is true.

testCase.verifyThat([1 2 3; 4 5 6],HasLength(6) | HasElementCount(6))
Verification passed.

Test if the vector [3 NaN 5] has NaN and infinite values. The test fails because one of the and conditions is false.

testCase.verifyThat([3 NaN 5],HasNaN & HasInf)
Verification failed.
    ---------------------
    Framework Diagnostic:
    ---------------------
    AndConstraint failed.
    --> + [First Condition]:
         |   HasNaN passed.
         |   --> Indices that have NaN values:
         |           2
         |   
         |   Actual Value:
         |        3   NaN     5
    --> AND
        + [Second Condition]:
         |   HasInf failed.
         |   --> At least one element must be Inf or -Inf.
         |   
         |   Actual Value:
         |        3   NaN     5
        -+---------------------

Create a Boolean constraint that determines if a value is the same size as an expected value.

In a file in your current folder, create a class named IsSameSizeAs that derives from matlab.unittest.constraints.BooleanConstraint, and implement the satisfiedBy, getDiagnosticFor, and getNegativeDiagnosticFor methods.

classdef IsSameSizeAs < matlab.unittest.constraints.BooleanConstraint
    properties (SetAccess=immutable)
        ValueWithExpectedSize
    end

    methods
        % Class constructor
        function constraint = IsSameSizeAs(value)
            constraint.ValueWithExpectedSize = value;
        end

        % Determine if the actual value satisfies the constraint
        function tf = satisfiedBy(constraint,actual)
            tf = constraint.sizeMatchesExpected(actual);
        end

        % Produce a diagnostic for the constraint
        function diagnostic = getDiagnosticFor(constraint,actual)
            import matlab.automation.diagnostics.StringDiagnostic
            if constraint.sizeMatchesExpected(actual)
                diagnostic = StringDiagnostic("IsSameSizeAs passed.");
            else
                diagnostic = StringDiagnostic( ...
                    "IsSameSizeAs failed." + newline + "Actual Size: [" ...
                    + int2str(size(actual)) + "]" + newline ...
                    + "Expected Size: [" ...
                    + int2str(size(constraint.ValueWithExpectedSize)) ...
                    + "]");
            end
        end
    end

    methods (Access=protected)
        % Produce a diagnostic for the negated constraint
        function diagnostic = getNegativeDiagnosticFor(constraint,actual)
            import matlab.automation.diagnostics.StringDiagnostic
            if constraint.sizeMatchesExpected(actual)
                diagnostic = StringDiagnostic( ...
                    "Negated IsSameSizeAs failed." + newline + ...
                    "Actual and expected sizes were the same ([" ...
                    + int2str(size(actual)) + ...
                    "]) but should not have been.");
            else
                diagnostic = StringDiagnostic( ...
                    "Negated IsSameSizeAs passed.");
            end
        end
    end

    methods (Access=private)
        % Determine if the actual and expected values are the same size
        function tf = sizeMatchesExpected(constraint,actual)
            tf = isequal(size(actual), ...
                size(constraint.ValueWithExpectedSize));
        end
    end
end

Create a test case for interactive testing.

testCase = matlab.unittest.TestCase.forInteractiveUse;

Verify that a 5-by-5 matrix of zeros is both the same size as a 5-by-5 matrix of ones and not the same size as a 1-by-5 vector of ones by using the IsSameSizeAs Boolean constraint.

testCase.verifyThat(zeros(5), ...
    IsSameSizeAs(ones(5)) & ~IsSameSizeAs(ones(1,5)))
Verification passed.

Version History

Introduced in R2013a