How to assert Rest Client Exception?

Question

I'm trying to assert the rest client exception. My piece of code is as follows:

public class SomeClass {

    public SomeResponse postMessage() {
        SomeBean requestObject = new SomeBean();
        SomeResponse response = null;
        try{
            response =  restTemaple.postForEntity("http://someUrl", requestObject, SomeResponse.class);
        } catch(RestTemplateException e) {
            Sysout("Rest Template Exception!");
        }

        return response;
    }

}

My Test case is as follows:

@RunWith(MockitoJUnitRunner.class)
@ActiveProfiles("test")
@PropertySource("classpath:application-test.properties")
public class testClass {

    @InjectMocks
    SomeClass service;

    @Mock
    RestTempalte restTemplate;

    @Test (expected = RestTemplateException.class)
    public void myTest() {
        Mockito.when(
                restTemplate.postForEntity(Mockito.anyString(), Mockito.any(SomeBean.class), Mockito.any()))
                .thenThrow(new RestClientException(null));

        service.postMessage();
        }

}

I'm getting a Junit assertion Error. Kindly find the stackTrace below:

java.lang.AssertionError: Expected exception: org.springframework.web.client.RestClientException
    at org.junit.internal.runners.statements.ExpectException.evaluate(ExpectException.java:32)
    at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:26)
    at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325)
    at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:78)
    at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:57)
    at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
    at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
    at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
    at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
    at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
    at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
    at org.mockito.internal.runners.DefaultInternalRunner$1.run(DefaultInternalRunner.java:79)
    at org.mockito.internal.runners.DefaultInternalRunner.run(DefaultInternalRunner.java:85)
    at org.mockito.internal.runners.StrictRunner.run(StrictRunner.java:39)
    at org.mockito.junit.MockitoJUnitRunner.run(MockitoJUnitRunner.java:163)
    at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:86)
    at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:459)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:678)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:382)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:192)

Kindly me on this. How can i throw and assert the rest client exception here?

Answer 1

You're catching the exception into postMessage without rethrowing the exception. If you handle the exception into postMessage, you do not have to test if the method execution will throw a RestClientException , as it's handled there. If you wait for your method to throw this exception, do not catch it and simply use throws RestClientException in your method declaration

public class SomeClass {

    public void postMessage() throws RestClientException {
        SomeBean requestObject = new SomeBean();
        return restTemaple.postForEntity("http://someUrl", requestObject, SomeResponse.class);
    }

}

Then you do not call postMessage in your unit test. You're just giving the instruction to your mock on how to react when RestTempalte.postForEntity is called.

    @Test (expected = RestClientException.class)
        public void myTest() {
            Mockito.when(
                    restTemplate.postForEntity(Mockito.anyString(), Mockito.any(SomeBean.class), Mockito.any()))
                    .thenThrow(new RestClientException(null));

            service.postMessage(); // something like that needed here
        }

It's also weird that you return something in postMessage as the return type of the method is void

public SomeResponse postMessage() throws RestClientException {
    SomeBean requestObject = new SomeBean();
    return restTemaple.postForEntity("http://someUrl", requestObject, SomeResponse.class);
}

Looks better