Question: how to mock GraphServiceClient properly when using with PageIterator ?

[denysobukh]

I'm using GraphServiceClient along with PageIterator in my code to go over all response pages.

UserCollectionResponse userCollectionResponse = graphClient.users().get();
		List<User> users = new LinkedList<>();
		PageIterator<User, UserCollectionResponse> graphResponsePageIterator = new PageIterator.Builder<User, UserCollectionResponse>()
				.client(client)
				.collectionPage(userCollectionResponse)
				.collectionPageFactory(UserCollectionResponse::createFromDiscriminatorValue)
				.processPageItemCallback(user -> {
					users.add(user);
					return true;
				}).build();
		graphResponsePageIterator.iterate();

I need to test my code. How to mock GraphServiceClient methods/responses properly to make it satisfy PageIterator invocations?

minimal mocking which I found working is :

                var client = Mockito.mock(GraphServiceClient.class, RETURNS_DEEP_STUBS);
		var user = new User();
		user.setId("43");
		user.setDisplayName("43");
		user.setMail("43");
		when(client.users().get().getValue()).thenReturn(List.of(user));
		when(client.users().get().getFieldDeserializers().containsKey("value")).thenReturn(true);

but it only works when a single test. When there are multiple @Test in a suit, they fail sporadically from time to time.

How to mock responses of GraphServiceClient to make it work with PageIterator?