matlab.mock.actions.ThrowException Class

Namespace: matlab.mock.actions

Throw exception when method is called or when property is set or accessed

Description

To specify that the framework throws an exception when a mock object method is invoked or when a mock object property is set or accessed, use the ThrowException class. You can use this action to inject error conditions into the system under test.

Construction

action = ThrowException throws an exception when a method is called or a property is set or accessed.

action = ThrowException(exception) specifies the exception that the mock throws.

Input Arguments

exception — Exception to throw

scalar MException object

Exception for the framework to throw at method call or property interaction, specified as a scalar MException object.

Example: MException('MyProduct:myID','My exception message.')

Methods

repeat	Repeat throwing exception
then	Action for mock object interaction or action subsequent to throwing exception

Copy Semantics

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

Examples

Throw Exception for Particular Mock Method Inputs

Create a mock for a bank account class.

testCase = matlab.mock.TestCase.forInteractiveUse;
[mock,behavior] = testCase.createMock('AddedMethods',"deposit");

Set up behavior.

import matlab.mock.actions.ThrowException
import matlab.unittest.constraints.IsLessThan
when(behavior.deposit(IsLessThan(0)),ThrowException(MException( ...
    'Account:deposit:Negative','Deposit amount must be positive.')))

Use the mock.

mock.deposit(10)
mock.deposit(-10)

Error using matlab.mock.internal.MockContext/createMockObject/mockMethodCallback (line 382)
Deposit amount must be positive.

Alternatives

For simple definition of outputs, you can use the throwExceptionWhen method of the matlab.mock.TestCase class. However, there is more functionality when you use the ThrowException action.

Version History

Introduced in R2017a