How addAll works with mocked paginated query

Question

I have to add the PaginatedQueryList from to secondList which comes from dynamoDbMapper.query for testing. How can I achieve it?

List exampleList = secondList.addAll(dynamoDbMapper.query(MyDAOClass.class, queryExpression));

I tried to mock the PaginatedQueryList but am getting null pointer exception because elements in mocked PaginatedQueryList is empty.

Any suggestions please?

Answer 1

You can do the following and it will work:

1. Create mock for paginated result.

   @Mock private PaginatedQueryList<Object> queryResult;

2. Return mocked result when query is called.

   when(dynamoDBMapper.query(any(), any())).thenReturn(queryResult);

3. set result in paginated result by mocking it with an array of expected list, say, firstList.

   when(queryResult.toArray()).thenReturn(firstList);

4. Add result in secondList.

   List exampleList = secondList.addAll(firstlist)