Question: How Do You Test A Method Which Does Not Return Any Value?

How do you test a method that does not return anything JUnit?

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) ..

Should private methods be unit tested?

The short answer is that you shouldn’t test private methods directly, but only their effects on the public methods that call them. Unit tests are clients of the object under test, much like the other classes in the code that are dependent on the object. … The test should only be accessing the class’ public interface.

How do you return a void method in Java?

You declare a method’s return type in its method declaration. Within the body of the method, you use the return statement to return the value. Any method declared void doesn’t return a value. It does not need to contain a return statement, but it may do so.

Why void does not return any value?

Void functions are created and used just like value-returning functions except they do not return a value after the function executes. In lieu of a data type, void functions use the keyword “void.” A void function performs a task, and then control returns back to the caller–but, it does not return a value.

Can you unit test a void method?

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 logic for the method is simple.

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 you test a method that returns void?

How to unit test a method that has void as return typeReturn a type anyway, even though you don’t use it. … Check what the method changed, like records in the database. … Split the methods so that one portion of it returns something, and the second method just takes the result and uses it. … Expose internals by using the InternalsVisibleTo attribute.More items…•

Which method does not return any value?

void methodvoid method: A method that does not return a value.

How do you call a void method in JUnit?

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.

When an argument is passed to a method?

Arguments are passed by value. When invoked, a method or a constructor receives the value of the variable passed in. When the argument is of primitive type, “pass by value” means that the method cannot change its value.

What is true of a void method?

A void method is one that simply performs a task and then terminates. A value – returning method not only performs a task but also sends a value back to the code that called it. … It causes the method to end execution and it returns a value to the statement that called the method.

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.