How can I mock Google's Geocoding API request using mockito/powermock?

Question

I want to unit test this method using mockito/powermock:

@Service
public class GoogleApiService {

    private static final Logger logger = LoggerFactory.getLogger(GoogleApiService.class);

    private static final String LANGUAGE = "es";

    private List<AddressType> addressTypes = Arrays.asList(
            AddressType.LOCALITY,
            AddressType.ADMINISTRATIVE_AREA_LEVEL_2,
            AddressType.ADMINISTRATIVE_AREA_LEVEL_1,
            AddressType.COUNTRY
    );

    @Autowired
    private GeoApiContext geoApiContext;

    public String getLocalityFromLatLng(LatLng latLng) throws Exception {
        logger.debug("getLocalityFromLatLng");

        GeocodingResult[] geocodingResults = GeocodingApi.newRequest(geoApiContext)
            .latlng(latLng)
            .await();
        for (GeocodingResult geocodingResult : geocodingResults) {
            AddressType addressType = geocodingResult.types[0];
            if (addressTypes.contains(addressType)) {
                return geocodingResult.formattedAddress;
            }
        }
        return StringUtils.EMPTY;
    }

}

this is what i have tried:

@PrepareForTest(GeocodingApi.class)
public class GoogleApiServiceUnitTest extends AbstractUnitTest {

    private static final Double LATITUDE = -38.010403;
    private static final Double LONGITUDE = -57.558408;

    @Mock
    private GeoApiContext geoApiContext;

    @InjectMocks
    private GoogleApiService googleApiService;

    @Test
    public void testGetLocalityFromLatLng() throws Exception {

        LatLng latLng = new LatLng(LATITUDE, LONGITUDE);
        GeocodingResult geocodingResult = new GeocodingResult();
        GeocodingResult[] geocodingResults = new GeocodingResult[] { geocodingResult };

        GeocodingApiRequest geocodingApiRequest = new GeocodingApiRequest(geoApiContext);
        geocodingApiRequest.latlng(latLng);

        mockStatic(GeocodingApi.class);

        // when(GeocodingApi.newRequest(geoApiContext))
           //  .thenReturn(geocodingApiRequest);

        // when(GeocodingApi.newRequest(geoApiContext).latlng(latLng))
           //  .thenReturn(geocodingApiRequest);

        when(GeocodingApi.newRequest(geoApiContext).latlng(latLng).await())
            .thenReturn(geocodingResults);

        String locality = googleApiService.getLocalityFromLatLng(latLng);

        assertThat(locality, is(notNullValue()));

        verifyStatic(times(1));
        GeocodingApi.newRequest(geoApiContext).latlng(latLng).await();

        verifyNoMoreInteractions(geoApiContext);
    }

}

i'm getting NullPointerException. Here is the stack trace:

java.lang.NullPointerException
at com.google.maps.PendingResultBase.await(PendingResultBase.java:56)
at com.beermap.server.unit.service.GoogleApiServiceUnitTest.testGetLocalityFromLatLng(GoogleApiServiceUnitTest.java:57)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at org.junit.internal.runners.TestMethod.invoke(TestMethod.java:68)
at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl$PowerMockJUnit44MethodRunner.runTestMethod(PowerMockJUnit44RunnerDelegateImpl.java:310)
at org.junit.internal.runners.MethodRoadie$2.run(MethodRoadie.java:89)
at org.junit.internal.runners.MethodRoadie.runBeforesThenTestThenAfters(MethodRoadie.java:97)
at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl$PowerMockJUnit44MethodRunner.executeTest(PowerMockJUnit44RunnerDelegateImpl.java:294)
at org.powermock.modules.junit4.internal.impl.PowerMockJUnit47RunnerDelegateImpl$PowerMockJUnit47MethodRunner.executeTestInSuper(PowerMockJUnit47RunnerDelegateImpl.java:127)
at org.powermock.modules.junit4.internal.impl.PowerMockJUnit47RunnerDelegateImpl$PowerMockJUnit47MethodRunner.executeTest(PowerMockJUnit47RunnerDelegateImpl.java:82)
at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl$PowerMockJUnit44MethodRunner.runBeforesThenTestThenAfters(PowerMockJUnit44RunnerDelegateImpl.java:282)
at org.junit.internal.runners.MethodRoadie.runTest(MethodRoadie.java:87)
at org.junit.internal.runners.MethodRoadie.run(MethodRoadie.java:50)
at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl.invokeTestMethod(PowerMockJUnit44RunnerDelegateImpl.java:207)
at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl.runMethods(PowerMockJUnit44RunnerDelegateImpl.java:146)
at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl$1.run(PowerMockJUnit44RunnerDelegateImpl.java:120)
at org.junit.internal.runners.ClassRoadie.runUnprotected(ClassRoadie.java:34)
at org.junit.internal.runners.ClassRoadie.runProtected(ClassRoadie.java:44)
at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl.run(PowerMockJUnit44RunnerDelegateImpl.java:122)
at org.powermock.modules.junit4.common.internal.impl.JUnit4TestSuiteChunkerImpl.run(JUnit4TestSuiteChunkerImpl.java:106)
at org.powermock.modules.junit4.common.internal.impl.AbstractCommonPowerMockRunner.run(AbstractCommonPowerMockRunner.java:53)
at org.powermock.modules.junit4.PowerMockRunner.run(PowerMockRunner.java:59)
at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:78)
at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:212)
at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:68)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at com.intellij.rt.execution.application.AppMain.main(AppMain.java:140)

is in the await() call line

EDIT: this is how it looks now, it is still not working

btw, @RunWith(PowerMockRunner.class) is in AbstractUnitTest

@Test
public void testGetLocalityFromLatLng() throws Exception {

    LatLng latLng = new LatLng(LATITUDE, LONGITUDE);
    GeocodingResult geocodingResult = new GeocodingResult();
    geocodingResult.types = new AddressType[] { AddressType.LOCALITY };
    geocodingResult.formattedAddress = FORMATTED_ADDRESS;
    GeocodingResult[] geocodingResults = new GeocodingResult[] { geocodingResult };

    GeocodingApiRequest geocodingApiRequest = mock(GeocodingApiRequest.class);

    mockStatic(GeocodingApi.class);

    when(geocodingApiRequest.latlng(latLng)).thenReturn(geocodingApiRequest);
    when(geocodingApiRequest.await()).thenReturn(geocodingResults); // NPE here
    when(GeocodingApi.newRequest(geoApiContext)).thenReturn(geocodingApiRequest);

    String locality = googleApiService.getLocalityFromLatLng(latLng);

    assertThat(locality, is(notNullValue()));

    // verifyStatic(times(1));
    // GeocodingApi.newRequest(geoApiContext).latlng(latLng).await();

    // verifyNoMoreInteractions(geoApiContext);

}

and the stack:

java.lang.NullPointerException
at com.google.maps.PendingResultBase.makeRequest(PendingResultBase.java:79)
at com.google.maps.PendingResultBase.await(PendingResultBase.java:55)
at com.beermap.server.unit.service.GoogleApiServiceUnitTest.testGetLocalityFromLatLng(GoogleApiServiceUnitTest.java:56)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at org.junit.internal.runners.TestMethod.invoke(TestMethod.java:68)
at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl$PowerMockJUnit44MethodRunner.runTestMethod(PowerMockJUnit44RunnerDelegateImpl.java:310)
at org.junit.internal.runners.MethodRoadie$2.run(MethodRoadie.java:89)
at org.junit.internal.runners.MethodRoadie.runBeforesThenTestThenAfters(MethodRoadie.java:97)
at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl$PowerMockJUnit44MethodRunner.executeTest(PowerMockJUnit44RunnerDelegateImpl.java:294)
at org.powermock.modules.junit4.internal.impl.PowerMockJUnit47RunnerDelegateImpl$PowerMockJUnit47MethodRunner.executeTestInSuper(PowerMockJUnit47RunnerDelegateImpl.java:127)
at org.powermock.modules.junit4.internal.impl.PowerMockJUnit47RunnerDelegateImpl$PowerMockJUnit47MethodRunner.executeTest(PowerMockJUnit47RunnerDelegateImpl.java:82)
at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl$PowerMockJUnit44MethodRunner.runBeforesThenTestThenAfters(PowerMockJUnit44RunnerDelegateImpl.java:282)
at org.junit.internal.runners.MethodRoadie.runTest(MethodRoadie.java:87)
at org.junit.internal.runners.MethodRoadie.run(MethodRoadie.java:50)
at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl.invokeTestMethod(PowerMockJUnit44RunnerDelegateImpl.java:207)
at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl.runMethods(PowerMockJUnit44RunnerDelegateImpl.java:146)
at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl$1.run(PowerMockJUnit44RunnerDelegateImpl.java:120)
at org.junit.internal.runners.ClassRoadie.runUnprotected(ClassRoadie.java:34)
at org.junit.internal.runners.ClassRoadie.runProtected(ClassRoadie.java:44)
at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl.run(PowerMockJUnit44RunnerDelegateImpl.java:122)
at org.powermock.modules.junit4.common.internal.impl.JUnit4TestSuiteChunkerImpl.run(JUnit4TestSuiteChunkerImpl.java:106)
at org.powermock.modules.junit4.common.internal.impl.AbstractCommonPowerMockRunner.run(AbstractCommonPowerMockRunner.java:53)
at org.powermock.modules.junit4.PowerMockRunner.run(PowerMockRunner.java:59)
at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:78)
at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:212)
at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:68)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at com.intellij.rt.execution.application.AppMain.main(AppMain.java:140)

Thanks in advance

Hbeam

Can you add the null pointer stack trace? – Skyscraper

Answer 1

There are several mistakes here and it show that you have misunderstanding of mocking. Let analyse them:

At first, I hope it's copy-past mistake, you don't have @RunWith(PowerMockRunner.class), otherwise you'll get another exception.

Second point, this commented out line is right when(GeocodingApi.newRequest(geoApiContext)).thenReturn(geocodingApiRequest);. When static method of the GeocodingApithen you want to return geocodingApiRequest.

At last, but most important point, this line is incorrect: when(GeocodingApi.newRequest(geoApiContext).latlng(latLng).await()).thenReturn(geocodingResults);

Only one static call will be mocked here: GeocodingApi.newRequest(geoApiContext).

And instance of really object will be return, because you create a new instance GeocodingApiRequest geocodingApiRequest = new GeocodingApiRequest(geoApiContext);.

The latlng(latLng) method is called from really object. And it's really call, not mocked. But seems to me you also want to mock it.

Then let's mock it: GeocodingApiRequest geocodingApiRequest = mock(GeocodingApiRequest.class);

After. mock all calls that need to be mocked:

when(geocodingApiRequest.latlng(latLng)).thenReturn(geocodingApiRequest);
when(geocodingApiRequest.await()).thenReturn(geocodingResults);

Another mistake, but so important as previous and more obviously: required files isn't set for geocodingResult.

GeocodingResult geocodingResult = new GeocodingResult();
geocodingResult.types = new AddressType[]{ AddressType.LOCALITY};
geocodingResult.formattedAddress = "Some address";

The full working test:

@RunWith(PowerMockRunner.class)
@PrepareForTest({GeocodingApi.class, GeocodingApiRequest.class})
public class GoogleApiServiceUnitTest  {

    private static final Double LATITUDE = -38.010403;
    private static final Double LONGITUDE = -57.558408;

    @Mock
    private GeoApiContext geoApiContext;

    @InjectMocks
    private GoogleApiService googleApiService;

    @Test
    public void testGetLocalityFromLatLng() throws Exception {

        LatLng latLng = new LatLng(LATITUDE, LONGITUDE);
        GeocodingResult geocodingResult = new GeocodingResult();
        geocodingResult.types = new AddressType[]{ AddressType.LOCALITY};
        geocodingResult.formattedAddress = "Some address";

        GeocodingResult[] geocodingResults = new GeocodingResult[] { geocodingResult };

        GeocodingApiRequest geocodingApiRequest = mock(GeocodingApiRequest.class);
        when(geocodingApiRequest.latlng(latLng)).thenReturn(geocodingApiRequest);
        when(geocodingApiRequest.await()).thenReturn(geocodingResults);

        mockStatic(GeocodingApi.class);

        when(GeocodingApi.newRequest(eq(geoApiContext)))
          .thenReturn(geocodingApiRequest);

        String locality = googleApiService.getLocalityFromLatLng(latLng);

        assertThat(locality, is(notNullValue()));

        verifyStatic(times(1));
        GeocodingApi.newRequest(geoApiContext);

        // add verification other mock if you really need it

        verifyNoMoreInteractions(geoApiContext);
    }
}

Annora

thanks, it helps, but is still not working, i'm still getting NPE in await() call, I edited my test (see edit in answer) and also copy/paste your solution, and both fails in the same line. – Hbeam

Have you added the 'GeocodingApiRequest.class' to '@PrepareForTest'? – Annora

oh, I forgot, but I added now and is still not working.. same error – Hbeam

Hmm, I've tested my code before posting, so another guesswork what could be different, it's using 'Mockito.mock' instead 'PowerMockito.mock'. – Annora

excellent! that was the trick! thank you very much! I will update the question for any other with the same problem. Thanks again! – Hbeam

@ArthurZagretdinov Have you upgraded to the latest version of Powermock 3 and tried to do the same thing? I'm looking for answers as I'm getting NPE... github.com/powermock/powermock/issues/1078 – Inotropic

I've just solved the problem without using PowerMock. From Mockito 3.6 version it is possible to mock static methods. I switched from mockito-core to mockito-inline 3.12.0. Mine code looks the same as above, just another imports and it works fine. – Ternan