public interface OngoingStubbing<T> extends IOngoingStubbing
when(mock.someMethod()).thenReturn(10);
//you can use flexible argument matchers, e.g:
when(mock.someMethod(anyString())).thenReturn(10);
//setting exception to be thrown:
when(mock.someMethod("some arg")).thenThrow(new RuntimeException());
//you can set different behavior for consecutive method calls.
//Last stubbing (e.g: thenReturn("foo")) determines the behavior of further consecutive calls.
when(mock.someMethod("some arg"))
.thenThrow(new RuntimeException())
.thenReturn("foo");
//There is a shorter way of consecutive stubbing:
when(mock.someMethod()).thenReturn(1,2,3);
when(mock.otherMethod()).thenThrow(exc1, exc2);
Mockito.when(T)| Modifier and Type | Method and Description |
|---|---|
<M> M |
getMock()
Returns the mock that was used for this stub.
|
OngoingStubbing<T> |
then(Answer<?> answer)
Sets a generic Answer for the method.
|
OngoingStubbing<T> |
thenAnswer(Answer<?> answer)
Sets a generic Answer for the method.
|
OngoingStubbing<T> |
thenCallRealMethod()
Sets the real implementation to be called when the method is called on a mock object.
|
OngoingStubbing<T> |
thenReturn(T value)
Sets a return value to be returned when the method is called.
|
OngoingStubbing<T> |
thenReturn(T value,
T... values)
Sets consecutive return values to be returned when the method is called.
|
OngoingStubbing<T> |
thenThrow(Class<? extends Throwable> throwableType)
Sets a Throwable type to be thrown when the method is called.
|
OngoingStubbing<T> |
thenThrow(Class<? extends Throwable> toBeThrown,
Class<? extends Throwable>... nextToBeThrown)
Sets Throwable classes to be thrown when the method is called.
|
OngoingStubbing<T> |
thenThrow(Throwable... throwables)
Sets Throwable objects to be thrown when the method is called.
|
OngoingStubbing<T> thenReturn(T value)
when(mock.someMethod()).thenReturn(10);
Mockito.when(T)value - return valueOngoingStubbing<T> thenReturn(T value, T... values)
when(mock.someMethod()).thenReturn(1, 2, 3);
See examples in javadoc for Mockito.when(T)
value - first return valuevalues - next return valuesOngoingStubbing<T> thenThrow(Throwable... throwables)
when(mock.someMethod()).thenThrow(new RuntimeException());
You can specify throwables to be thrown for consecutive calls. In that case the last throwable determines the behavior of further consecutive calls.
If throwable is null then exception will be thrown.
See examples in javadoc for Mockito.when(T)
throwables - to be thrown on method invocationOngoingStubbing<T> thenThrow(Class<? extends Throwable> throwableType)
when(mock.someMethod()).thenThrow(RuntimeException.class);
If the throwable class is a checked exception then it has to match one of the checked exceptions of the stubbed method signature.
If throwable is null then exception will be thrown.
See examples in javadoc for Mockito.when(T)
throwableType - to be thrown on method invocationOngoingStubbing<T> thenThrow(Class<? extends Throwable> toBeThrown, Class<? extends Throwable>... nextToBeThrown)
when(mock.someMethod()).thenThrow(RuntimeException.class);
Each throwable class will be instantiated for each method invocation.
If throwableTypes contain a checked exception then it has to
match one of the checked exceptions of method signature.
You can specify throwableTypes to be thrown for consecutive calls.
In that case the last throwable determines the behavior of further consecutive calls.
If throwable is null then exception will be thrown.
See examples in javadoc for Mockito.when(T)
Note since JDK 7, invoking this method will raise a compiler warning "possible heap pollution",
this API is safe to use. If you don't want to see this warning it is possible to chain thenThrow(Class)
toBeThrown - to be thrown on method invocationnextToBeThrown - next to be thrown on method invocationOngoingStubbing<T> thenCallRealMethod()
As usual you are going to read the partial mock warning: Object oriented programming is more less tackling complexity by dividing the complexity into separate, specific, SRPy objects. How does partial mock fit into this paradigm? Well, it just doesn't... Partial mock usually means that the complexity has been moved to a different method on the same object. In most cases, this is not the way you want to design your application.
However, there are rare cases when partial mocks come handy: dealing with code you cannot change easily (3rd party interfaces, interim refactoring of legacy code etc.) However, I wouldn't use partial mocks for new, test-driven & well-designed code.
// someMethod() must be safe (e.g. doesn't throw, doesn't have dependencies to the object state, etc.)
// if it isn't safe then you will have trouble stubbing it using this api. Use Mockito.doCallRealMethod() instead.
when(mock.someMethod()).thenCallRealMethod();
// calls real method:
mock.someMethod();
Mockito.spy(Object) to find out more about partial mocks.
Mockito.spy() is a recommended way of creating partial mocks.
The reason is it guarantees real methods are called against correctly constructed object because you're responsible for constructing the object passed to spy() method.
See examples in javadoc for Mockito.when(T)
OngoingStubbing<T> thenAnswer(Answer<?> answer)
when(mock.someMethod(10)).thenAnswer(new Answer<Integer>() {
public Integer answer(InvocationOnMock invocation) throws Throwable {
return (Integer) invocation.getArguments()[0];
}
}
answer - the custom answer to execute.OngoingStubbing<T> then(Answer<?> answer)
thenAnswer(Answer). This alias allows
more readable tests on occasion, for example:
//using 'then' alias:
when(mock.foo()).then(returnCoolValue());
//versus good old 'thenAnswer:
when(mock.foo()).thenAnswer(byReturningCoolValue());
answer - the custom answer to execute.thenAnswer(Answer)<M> M getMock()
It allows to create a stub in one line of code. This can be helpful to keep test code clean. For example, some boring stub can be created & stubbed at field initialization in a test:
public class CarTest {
Car boringStubbedCar = when(mock(Car.class).shiftGear()).thenThrow(EngineNotStarted.class).getMock();
@Test public void should... {}
M - The mock type given by the variable type.