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matlab.mock.actions.ThrowException Class

Namespace: matlab.mock.actions

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


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.


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

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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.')


repeatRepeat throwing exception
thenAction for mock object interaction or action subsequent to throwing exception

Copy Semantics

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


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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.

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


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