ElasticSearch Unit Testing - best practices and approach

[Calvin-J-Scott (Calvin Scott)]

Hi All,

I am currently facing a issue when trying to unit test my elasticsearch search method.
Here is my Service:

@Service
@Slf4j
public class FullService {

private final RestHighLevelClient client;
private final ObjectMapper objectMapper;
private final SearchRequest searchRequest = new SearchRequest();
private final SearchSourceBuilder searchSourceBuilder = new SearchSourceBuilder();
private       SearchResponse searchResponse = new SearchResponse();
private final ESBuilder esBuilder = new ESBuilder();


FullService(RestHighLevelClient client, ObjectMapper objectMapper) {
    this.client = client;
    this.objectMapper = objectMapper;
    searchRequest.indices(INDEX);

  }

public Results findAll() throws IOException {
    searchSourceBuilder.query(QueryBuilders.matchAllQuery());
    searchRequest.source(searchSourceBuilder);
    searchResponse = client.search(searchRequest, RequestOptions.DEFAULT);

    return getAllSearchResult(searchResponse);

  }

public Results findByRequestSearch(UserSearchRequest request) throws IOException {
    searchSourceBuilder.query(esBuilder.buildQuery(request));
    searchRequest.source(searchSourceBuilder);
    searchResponse = client.search(searchRequest,RequestOptions.DEFAULT);
    return getAllSearchResult(searchResponse);
  } 
}

The Client is built outside the class in an ESConfig file:

@Configuration
class ESConfig {


@Value("${elasticsearch.host}")
private String host;

@Value("${elasticsearch.port}")
private int port;

@Value("${elasticsearch.username}")
private String userName;

@Value("${elasticsearch.password}")
private String password;

@Bean(destroyMethod = "close")
public RestHighLevelClient restClient() {

    final CredentialsProvider credentialsProvider = new BasicCredentialsProvider();
    credentialsProvider.setCredentials(AuthScope.ANY,
            new UsernamePasswordCredentials(userName, password));

    RestClientBuilder builder = RestClient.builder(new HttpHost(host, port))
            .setHttpClientConfigCallback(httpClientBuilder -> httpClientBuilder.setDefaultCredentialsProvider(credentialsProvider));


    return new RestHighLevelClient(builder);

}
}

So I'm trying to test the findByRequestSearch() method. but keep getting a null pointer exception

Here is my Test Class:

@RunWith(PowerMockRunner.class)
public class powerMockTest {

@Mock
RestHighLevelClient highLevelClient;


ObjectMapper objectMapper;
SearchSourceBuilder searchSourceBuilder;
ESBuilder esBuilder;


private FullService fullService;

@Mock
SearchResponse searchResponse;

@Before
public void setUp() throws Exception {
    objectMapper = new ObjectMapper();
    fullService = new FullService(highLevelClient,objectMapper);
    searchSourceBuilder = new SearchSourceBuilder();
    esBuilder = new ESBuilder();

}

@Test
public void testFindByRequest() throws IOException {

    //Build Request
    UserSearchRequest request = new UserSearchRequest();
    SearchCriteria searchCriteria = new SearchCriteria();
    List<SearchTerms> searchTermsList = new ArrayList<>();
    SearchTerms searchTerms = new SearchTerms();

    searchTerms.setAttribute("compoundName");
    searchTerms.setValue("Odell");
    searchTermsList.add(searchTerms);
    searchCriteria.setSearchTerms(searchTermsList);
    request.setSearchCriteria(searchCriteria);

    //ES Search Request
    SearchRequest searchRequest = new SearchRequest();
    searchSourceBuilder.query(esBuilder.buildQuery(request));
    searchRequest.source(searchSourceBuilder);

    Mockito.when(highLevelClient.search(searchRequest, RequestOptions.DEFAULT)).thenReturn(searchResponse);

    Mockito.verify(highLevelClient,Mockito.times(1)).search(Mockito.any(SearchRequest.class),RequestOptions.DEFAULT);
    Mockito.verifyNoMoreInteractions(highLevelClient);

}}

Any Help with this would be appreciated but also any guidance on best practices around testing methods that call ES components.