Mockito change the arguments passed to a mock

Asked Aug 20 '21 at 07:52

Active Aug 20 '21 at 07:52

Viewed 262 times

i have a class which reads and writes values from/to a byte-buffer.

My write method looks like this:

public void write(final ByteBuffer buffer) {
    buffer.putInt(messageLength);
    buffer.putShort(version);
    foo.write(buffer);
    buffer.putInt(checkSum);
    ...
}

Now i want to write a Unit test for this method and i want the foo-object to be mocked (which is pretty easy). But is it possible that the mocked-foo instance actually does something to the buffer?

In this case when().thenReturn() doesn't help me since the return value is not used.

asked Aug 20 '21 at 07:52

maku

3

You can use an Answer when you want a mock to have a side effect. – tgdavies Aug 20 '21 at 08:00
You talk about the mocking void method I think. doNothing().when(foo).write(buffer); – Dmitrii B Aug 20 '21 at 08:51
But doing nothing is not what i want. I want to manipulate the byte buffer. – maku Aug 20 '21 at 10:04

Mockito change the arguments passed to a mock

0 Answers0