Consider dynamically created mocks when pre minimizing fuzzer output and properly initialize @Mock fields

[IlyaMuravjov]

Description

When fuzzer executions are pre minimized we should consider mocks that we were added during concrete executions for methods that were actually invoked, but whose behavior wasn't defined by the fuzzer itself.

Also, makes fixes field initialization (when creating @InjectMock field we should not mark @Mock fields as initialized).

How to test

Manual tests

Add the following method to OrderService in spring-boot-testing project and generate unit tests, using "Mock everything outside the class" mock strategy and 100% fuzzing.

public double getTotalPrice() {
    return orderRepository.findAll().stream().mapToDouble(Order::getPrice).sum();
}

There should be test with real list:

public void testGetTotalPriceReturnsZero() {
    List list = emptyList();
    (when(orderRepositoryMock.findAll())).thenReturn(list);

    double actual = simpleOrderService.getTotalPrice();

    assertEquals(0.0, actual, 1.0E-6);
}

There should be no tests with mocked lists:

public void testGetTotalPriceReturnsZero() {
    List listMock = mock(List.class);
    Stream streamMock = mock(Stream.class);
    DoubleStream doubleStreamMock = mock(DoubleStream.class);
    (when(doubleStreamMock.sum())).thenReturn(0.0);
    (when(streamMock.mapToDouble(any()))).thenReturn(doubleStreamMock);
    (when(listMock.stream())).thenReturn(streamMock);
    (when(orderRepositoryMock.findAll())).thenReturn(listMock);

    double actual = simpleOrderService.getTotalPrice();

    assertEquals(0.0, actual, 1.0E-6);
}

Self-check list

• I've set the proper labels for my PR (at least, for category and component).
• PR title and description are clear and intelligible.
• I've added enough comments to my code, particularly in hard-to-understand areas.
• The functionality I've repaired, changed or added is covered with automated tests.
• Manual tests have been provided optionally.
• The documentation for the functionality I've been working on is up-to-date.