@Test
public void testUserItemFilter() throws Exception {
Configuration conf = getConfiguration();
IDReader idReader = new IDReader(conf);
Map<Long, FastIDSet> userItemFilter = Maps.newHashMap();
long user1 = 1;
long user2 = 2;
idReader.addUserAndItemIdToUserItemFilter(userItemFilter, user1, 100L);
idReader.addUserAndItemIdToUserItemFilter(userItemFilter, user1, 200L);
idReader.addUserAndItemIdToUserItemFilter(userItemFilter, user2, 300L);
FastIDSet userIds = IDReader.extractAllUserIdsFromUserItemFilter(userItemFilter);
assertEquals(2, userIds.size());
assertTrue(userIds.contains(user1));
assertTrue(userIds.contains(user1));
setField(idReader, USER_ITEM_FILTER_FIELD, userItemFilter);
FastIDSet itemsForUser1 = idReader.getItemsToRecommendForUser(user1);
assertEquals(2, itemsForUser1.size());
assertTrue(itemsForUser1.contains(100L));
assertTrue(itemsForUser1.contains(200L));
FastIDSet itemsForUser2 = idReader.getItemsToRecommendForUser(user2);
assertEquals(1, itemsForUser2.size());
assertTrue(itemsForUser2.contains(300L));
FastIDSet itemsForNonExistingUser = idReader.getItemsToRecommendForUser(3L);
assertTrue(itemsForNonExistingUser.isEmpty());
}