Question: How Do You Test A Void Return Type In JUnit?

How do you mock a void return?

Mockito provides following methods that can be used to mock void methods.

doAnswer() : We can use this to perform some operations when a mocked object method is called that is returning void.

doThrow() : We can use doThrow() when we want to stub a void method that throws exception..

How do I private a JUnit method?

From this article: Testing Private Methods with JUnit and SuiteRunner (Bill Venners), you basically have 4 options:Don’t test private methods.Give the methods package access.Use a nested test class.Use reflection.

How do you write a JUnit test case in Java?

Following are the most commonly used annotations and their usage in a basic unit test written in JUnit 4.@Test – Marks the method as a test method.@Before and @After sandwiches each test method in the class.@BeforeClass and @AfterClass sandwiches all of the test methods in a JUnit test class.More items…•

Do nothing when a method is called Mockito?

doNothing: Is the easiest of the list, basically it tells Mockito to do nothing when a method in a mock object is called. Sometimes used in void return methods or method that does not have side effects, or are not related to the unit testing you are doing.

What are the features of JUnit?

Features of JUnitJUnit is an open source framework, which is used for writing and running tests.Provides annotations to identify test methods.Provides assertions for testing expected results.Provides test runners for running tests.JUnit tests allow you to write codes faster, which increases quality.More items…

How do you check which returns void?

It is possible to test methods that don’t return anything ( void ), but you must test that method’s side effects….You’d test this method by:Creating an ArrayList arr ;Adding some things to it;Invoking arr. clear() ;Checking assertEquals(arr. size(),0) .

Can we write junit test cases for void methods?

Whenever we write unit test cases for any method we expect a return value from the method and generally use assert for checking if the functions return the value that we expect it to return, but in the case of void methods, they do not return any value. … The method publishInformation() is also a void method.

What is verify method in Mockito?

Mockito Verify methods are used to check that certain behavior happened. We can use Mockito verify methods at the end of the testing method code to make sure that specified methods are called.

Is void a return type?

Void as a Function Return Type Void functions, also called nonvalue-returning functions, are used just like value-returning functions except void return types do not return a value when the function is executed. The void function accomplishes its task and then returns control to the caller.

What happens if you forget the return statement in a non void function?

Failure to return a value from a function with a non-void return type (other than main) will result in undefined behavior.

How do you mock a void in EasyMock?

If we just want to mock void method and don’t want to perform any logic, we can simply use expectLastCall(). andVoid() right after calling void method on mocked object. You can checkout complete project and more EasyMock examples from our GitHub Repository.

How do you test the void method in Junit?

How to verify that void methods were called using MockitoThe class under test is never mocked.The dependencies of the class under test need to be mocked.By calling a method on a mock object we will mock that method call.In your test, first perform the action under test then call verify() not the other way around.More items…

How do you end a void function?

Use return; instead of return(0); to exit a void function.

How do you mock a void method?

How to mock void methods with mockito – there are two options:doAnswer – If we want our mocked void method to do something (mock the behavior despite being void).doThrow – Then there is Mockito. doThrow() if you want to throw an exception from the mocked void method.

Can a void method have a return statement?

Any method declared void doesn’t return a value. It does not need to contain a return statement, but it may do so. … The data type of the return value must match the method’s declared return type; you can’t return an integer value from a method declared to return a boolean.