Java Unit test for Exception - junit

Question

public Document query(String uri) throws IOException, IllegalArgumentException
{
final HttpGet httpget = new HttpGet(uri);
final HttpResponse response = httpclient.execute(httpget);
final HttpEntity entity = response.getEntity();
Document doc = null;
try
{
DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
DocumentBuilder builder = factory.newDocumentBuilder();
doc = builder.parse(entity.getContent());
}
catch (SAXException e)
{
LOGGER.error(e);
throw new IllegalArgumentException("parse error" + e);
}
catch (ParserConfigurationException e)
{
LOGGER.error(e);
throw new IllegalArgumentException("parameter factor is invalid: " + e);
}
catch (IllegalStateException e)
{
LOGGER.error(e);
throw new IllegalArgumentException("null entity contetents" + e);
}
return doc;
}
#Test(expected = IllegalArgumentException.class)
public void testQuery_ParseExceptionThrown() throws Exception
{
String uri ="some uri";
EasyMock.expect(httpClient.execute(EasyMock.isA(HttpGet.class))).andReturn(mockResponse);
EasyMock.expect(mockResponse.getEntity()).andReturn(mockEntity);
EasyMock.expect(mockEntity.getContent()).andReturn(new ByteArrayInputStream(REPSONSE_EXAMPLE.getBytes()));
DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
DocumentBuilder builder = factory.newDocumentBuilder();
EasyMock.expect(builder.parse(EasyMock.isA(InputStream.class))).andThrow(
new IllegalArgumentException("expected"));
EasyMock.replay();
class.query(uri);
}
error:
java.lang.IllegalStateException: calling verify is not allowed in record state
at org.easymock.internal.MocksControl.verify(MocksControl.java:181)
at org.powermock.api.easymock.internal.invocationcontrol.EasyMockMethodInvocationControl.verify(EasyMockMethodInvocationControl.java:120)
at org.powermock.api.easymock.PowerMock.verify(PowerMock.java:1650)
at org.powermock.api.easymock.PowerMock.verifyAll(PowerMock.java:1586)
at com.amazon.ams.test.AbstractUnitTest.verifyMocks(AbstractUnitTest.java:78)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:606)
at org.junit.internal.runners.MethodRoadie.runAfters(MethodRoadie.java:145)
at org.junit.internal.runners.MethodRoadie.runBeforesThenTestThenAfters(MethodRoadie.java:99)
at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl$PowerMockJUnit44MethodRunner.executeTest(PowerMockJUnit44RunnerDelegateImpl.java:296)
at org.powermock.modules.junit4.internal.impl.PowerMockJUnit47RunnerDelegateImpl$PowerMockJUnit47MethodRunner.executeTestInSuper(PowerMockJUnit47RunnerDelegateImpl.java:112)
at org.powermock.modules.junit4.internal.impl.PowerMockJUnit47RunnerDelegateImpl$PowerMockJUnit47MethodRunner.executeTest(PowerMockJUnit47RunnerDelegateImpl.java:73)
at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl$PowerMockJUnit44MethodRunner.runBeforesThenTestThenAfters(PowerMockJUnit44RunnerDelegateImpl.java:284)
at org.junit.internal.runners.MethodRoadie.runTest(MethodRoadie.java:84)
at org.junit.internal.runners.MethodRoadie.run(MethodRoadie.java:49)
at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl.invokeTestMethod(PowerMockJUnit44RunnerDelegateImpl.java:209)
at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl.runMethods(PowerMockJUnit44RunnerDelegateImpl.java:148)
at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl$1.run(PowerMockJUnit44RunnerDelegateImpl.java:122)
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:120)
at org.powermock.modules.junit4.common.internal.impl.JUnit4TestSuiteChunkerImpl.run(JUnit4TestSuiteChunkerImpl.java:102)
at org.powermock.modules.junit4.common.internal.impl.AbstractCommonPowerMockRunner.run(AbstractCommonPowerMockRunner.java:53)
at org.powermock.modules.junit4.PowerMockRunner.run(PowerMockRunner.java:42)
at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:50)
at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:467)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:683)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:390)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:197)
I keep getting some errors like
java.lang.AssertionError: Expected exception: org.xml.sax.SAXException
java.lang.IllegalStateException: calling verify is not allowed in record state
There are 3 exceptions I need to write Junit test to get into the exception. Does anyone know how to use powermock or easymock class to write the unit test for it?

Answer 1

If you have a mock for the builder using easymock you can throw Exceptions instead of return values:
EasyMock.expect(builder.parse(myContent)).andThrow( myException);
Where myException is an Exception instance you want to throw (created by new MyException(...));
EDIT: example test code:
#Test
public void parseThrowsIllegalStateException(){
//... creating mock factory, builder and entity not shown
//create new Exception to be thrown
IllegalStateException expectedException = new IllegalStateException("expected");
EasyMock.expect(mockBuilder.parse(mockContent).andThrow(expectedException);
EasyMock.replay(...);
//exercise your system under test which tries to parse the entity's Content
//...
}
EDIT 2: now that you posted your actual test code I think the problem might be these lines:
EasyMock.expect(mockEntity.getContent()).andReturn(new ByteArrayInputStream(REPSONSE_EXAMPLE.getBytes()));
...
EasyMock.expect(builder.parse(new ByteArrayInputStream(malformed_XML.getBytes()))).andThrow(new SAXException("expected"));
I don't think ByteArrayInputStream overrides equals() so it is using Object.equals(). The ByteArrayInputStreams won't be equal so EasyMock will never throw the Exception
I would change the builder.parse() expectation to:
EasyMock.expect(builder.parse(EasyMock.isA(InputStream.class))).andThrow(new SAXException("expected"));
Which will throw when parse is called no matter what the inputStream is.
As a side note, your error message the mentioned "calling verify is not allowed in record state" but I don't see any calls to verify() or verifyAll() anywhere.