I used to rely on Mockito until today I have a final class with some static methods so I've to switched to JMockit. I knew nothing about it before so the question is: how can I apply the similar logic from Mockito to JMockit?
public final class ServiceData extends BaseData {
private List<Data> data;
public ServiceData(List<Data> data) {
this.data = data;
// something else
}
public static Container getContainer() {
return super.getContainer();
}
public Data getDataAt(Index index) {
return super.getContainer().get(index);
}
}
The test written in Mockito looks like:
#Test
public void test() {
ServiceData mockServiceData = mock(ServiceData.class);
Data mockData = mock(Data.class);
// only stubbing some of the methods
Container mockContainer = spy(Container.class);
doReturn(something).when(mockContainer.someMethod());
when(mockServiceData.getContainer()).thenReturn(mockContainer);
when(mockServiceData.getDataAt(any(Index.class)).thenReturn(mockData);
// some assertions
}
This won't work since Mockito cannot mock final classes nor static methods (getContainer)
So how can I write the same logic in JMockit? Thanks.
The following is the JMockit equivalent for the example test:
#Test
public void test(
#Mocked final ServiceData mockServiceData, #Mocked final Data mockData,
#Mocked final Container mockContainer)
{
// only stubbing some of the methods
new Expectations(mockContainer) {{
mockContainer.someMethod(); result = "something";
mockServiceData.getContainer(); result = mockContainer;
mockServiceData.getDataAt((Index) any); result = mockData;
}};
// some assertions
}
To mock static methods the syntax is the same, except that you would write ServiceData.getContainer(); result = mockContainer; instead.
Related
I am testig a public method and I want to verify if a private method, that have mocked params, is called.
All the answers I have found are using invoke method, but this was removed since JMockit v1.36
public class ClassToTest{
public void methodToTest(){
DependencyClass abc = new DependencyClass();
if(privateMethod1()){
privateMethod2(abc);
}
}
private boolean privateMethod1(){ return true; }
private void privateMethod2(DependencyClass abc){ abc.doStuff(); }
}
public class testClassToTest{
#Mocked
DependencyClass abc;
#Tested
ClassToTest testedClass;
#BeforeEach
public void setUp() {
testedClass = new ClassToTest();
}
#Test
public void testMethod(){
new MockUp<ClassToTest>() {
#Mock
private boolean privateMethod1() {
return true;
}
};
testedClass.methodToTest();
new FullVerificationsInOrder() {{
abc = new DependencyClass();
//Check here if privateMethod2(abc) gets called once
}};
}
You can use Powermock to mock and verify private methods.
Please check https://github.com/powermock/powermock/wiki/MockPrivate
You have two ways:
To level up your method's scope from private to package-private and after it, your method will become visible in the test.
Refactoring your code and encapsulate the private method to Predicate and after it, you can test your primary method and Predicate separately.
You can't test the private method by Junit.
I'm doing some unit test but I'm having problems trying to test a class. I have a class with a static builder method which returns the class instance:
public class MessageCaller {
public static MessageCaller builder() {
return new MessageCaller();
}
//Other methods
public String publish() {
//publishing to some Messages
return "something";
}
public MessageCaller withAttribute(String key, String value) {
//Some code
return this;
}
}
public class MessageCallerExtended extends MessageCaller {
private Map<String, String> attributes;
#Override
public MessageCaller withAttribute(String key, String value) {
if (this.attributes == null) {
this.attributes = new HashMap();
}
this.attributes.put(key, value);
return this;
}
//It's not working because it's calling the base class builder and is not possible to be Overriten
//because it's a static method.
public static MessageCallerExtended builder() {
return new MessageCallerExtended();
}
#Override
public String publish() {
return "test";
}
}
This is the method which I would like to test, the problem is that is calling the real publish method taking some time to finalize.
public void sendMessages(#Nonnull String group, #Nonnull String state) {
this.message.builder()
.toTopic(xxxx)
.withAttribute(xxx, xxx)
.withAttribute(xxx, xxx)
.withAttribute(xxx,xxx)
.publish();
}
I'm sending the message object in the constructor of the class.
I've created a Wrapper class to use in the unit test but the problem is that the builder method is static and for that reason is not possible to #Override, if I don't use the #Override tag I'll invoke the real builder method and then the real publish method and it is taking too much time to be processed, causing some problems, because is invoked for several unit test.
With Mockito I having similar issues with the static builder method, in fact it's not possible to mock static methods with Mockito. I'm not allowed to use another library like PowerMock for instance.
Any ideas?
I'm not very well-versed with Mockito but am trying to use mocks to test behaviour of a simulation, this is the class:
package simulator;
import java.util.Map;
import org.apache.commons.lang3.Validate;
import simulator.enums.Team;
import simulator.fixtures.Fixture;
public class SimulateBasketballMatchResult implements Simulation<Team> {
private final Fixture fixture;
public SimulateBasketballMatchResult(Fixture fixture) {
Validate.notNull(fixture, "fixture cannot be null");
this.fixture = fixture;
}
#Override
public Team simulate(Map<Team, Double> outcomeProbabilityMap) {
Validate.notNull(outcomeProbabilityMap, "outcomeProbabilityMap cannot be null");
final Team homeTeam = fixture.getHomeTeam();
final Team awayTeam = fixture.getAwayTeam();
double random = randomDoubleGenerator();
double homeWinProbability = outcomeProbabilityMap.get(homeTeam);
return random < homeWinProbability ? homeTeam : awayTeam;
}
public Double randomDoubleGenerator() {
return Math.random();
}
}
Below is the test class:
#RunWith(MockitoJUnitRunner.class)
public class SimulateBasketballMatchResultTest {
#Rule
public ExpectedException expectedException = ExpectedException.none();
private static final Map<Team, Double> MATCH_RESULT_PROBABILITY_MAP = new HashMap<>();
private static final Fixture FIXTURE = new Fixture(GOLDEN_STATE_WARRIORS, HOUSTON_ROCKETS, REGULAR_SEASON);
static {
MATCH_RESULT_PROBABILITY_MAP.put(FIXTURE.getHomeTeam(), 0.7d);
MATCH_RESULT_PROBABILITY_MAP.put(FIXTURE.getAwayTeam(), 0.3d);
}
#Mock
private SimulateBasketballMatchResult simulateBasketballMatchResult;
#Test
public void shouldReturnGoldenStateWarriorsAsWinner() {
when(simulateBasketballMatchResult.randomDoubleGenerator()).thenReturn(0.5d);
assertThat(simulateBasketballMatchResult.simulate(MATCH_RESULT_PROBABILITY_MAP), is(GOLDEN_STATE_WARRIORS));
}
}
I would like to assert that GOLDEN_STATE_WARRIORS is returned when the probability range is between 0 and 0.7- however I get an assertion error of null with my test code.
java.lang.AssertionError:
Expected: is <GOLDEN_STATE_WARRIORS>
but: was null
Expected :is <GOLDEN_STATE_WARRIORS>
simulateBasketballMatchResult is a mock object, so by default, it will return null for all its methods (that have a non-primitive return value, of course).
Instead of mocking that object, you should probably spy it:
#Spy
private SimulateBasketballMatchResult simulateBasketballMatchResult =
new SimulateBasketballMatchResult(Fixture);
Try this:
#Mock
private Fixture fixture;
private SimulateBasketballMatchResult simulator;
#Before
public void setUp() {
simulator = spy(new SimulateBasketballMatchResult(fixture));
doCallRealMethod().when(simulator).simulate();
}
#Test
public void shouldReturnGoldenStateWarriorsAsWinner() {
doReturn(0.5).when(simulator).randomDoubleGenerator();
when(fixture.getHomeTeam()).thenReturn(GOLDEN_STATE_WARRIORS);
when(fixture.getAwayTeam()).thenReturn(HOUSTON_ROCKETS);
assertThat(simulator.simulate(MATCH_RESULT_PROBABILITY_MAP), is(GOLDEN_STATE_WARRIORS));
}
Mockito.spy and #Spy allow you to mock some methods of a real object, but Mockito.mock and #Mock mock the whole object.
A mock in mockito is a normal mock (allows you to stub invocations; that is, return specific values out of method calls).
A spy in mockito is a partial mock (part of the object will be mocked and part will use real method invocations).
Read more
I am making a unit test for class in my app, it just a simple class and I thought i did everything right but the test failed saying
Wanted but not invoked:
mContextWeakReference.get();
-> at rahmat.com.app.utility.backwardcompatibility.StringResourceUtilTest.getString(StringResourceUtilTest.java:40)
Actually, there were zero interactions with this mock.
this is the class to be tested
public class StringResourceUtil {
private static StringResourceUtil sInstance;
private WeakReference<Context> mContextWeakReference;
public static StringResourceUtil getInstance() {
return sInstance;
}
#Inject
public StringResourceUtil(Context context) {
mContextWeakReference = new WeakReference<>(context);
sInstance = this; //NOSONAR
}
public String getString(int resId) {
return mContextWeakReference.get().getString(resId);
}}
this is unit test I made
public class StringResourceUtilTest {
private StringResourceUtil mResourceUtil;
#Mock
private Context mContext;
#Mock
private WeakReference<Context> mContextWeakReference;
#Before
public void setUp(){
MockitoAnnotations.initMocks(this);
mResourceUtil = new StringResourceUtil(mContext);
}
#Test
public void getString() {
int resId = 123;
mResourceUtil.getString(resId);
verify(mContextWeakReference).get().getString(eq(resId));
}}
any help would be much appreciated, thanks
Your StringUtil class is always creating a new object of mContextWeakReference object and even if you are making it, it won't inject automatically ( for that you use injectMock but no use here, since new object creation always happens internally).
public class StringResourceUtilTest {
private StringResourceUtil mResourceUtil;
#Mock
private Context mContext;
#Before
public void setUp(){
MockitoAnnotations.initMocks(this);
mResourceUtil = new StringResourceUtil(mContext);
// setup mock return type
// mock objects are not real,so need to moeck the behavior of method as well
when(mContext.getString(R.string.a123)).thenReturn("123");
}
#Test
public void getString() {
int resId = R.string.a123;
// check the return type
assertEquals("123",mResourceUtil.getString(resId));
}
}
Note: To verify the internal working, read
What is the difference between mocking and spying when using Mockito?
Because you creating mContextWeakReference = new WeakReference<>(context); in constructor, it will never been a mock in StringResourceUtil.
You can set prepared mock mContextWeakReference by using
org.springframework.test.util.ReflectionTestUtils.setField(mResourceUtil , "mContextWeakReference", mContextWeakReference);
Otherwise you should modifying StringResourceUtil class to be a testable
I'm using TestNG and JMockit for testing. My code goes like this:
public boolean testMethod(String a, String b) {
//processing .....
mockClass.mockMethod(a);
//processing....
}
The mockMethod():
Class MockClass {
public void mockMethod(String a) {
//some operations to mock
}
}
I'm using MockUp according to this question: (How to mock public void method using jmockit?)
I'm still getting the NPE. What am I doing wrong? Also, is it because I'm using it like this?
#Test
public void test() {
new Expectations() {
{
//for statements preceding mockMethod()....
new MockUp<MockClass>(){
#Mock
public void mockMethod(String a) {
//do nothing
}
};
}
};
}
I've put it outside Expectations() & used NonStrictExpectations too. How do I fix this?
If the method to be mocked is not returning anything, you don't need to do anything special in expectations. You can define your class to be mocked using #Injectable or #Mocked annotations in usual way. Optionally you can add an expectation to verify the number of times the method is called. Also you can add verification step to capture the argument "a" and do assertions on that. Refer below code sample.
#Tested
private MyClassToBeTested myClassToBeTested;
#Injectable
private MockClass mockClass;
#Test
public void test() {
// Add required expectations
new Expectations() {{
...
..
}};
// Invoke the method to be tested with test values;
String expectedA = "testValueA";
String expectedB = "testValueB";
boolean result = myClassToBeTested.testMethod(expectedA, expectedB);
// Assert the return value of the method
Assert.assertTrue(result);
// Do the verifications and assertions
new Verifications() {{
String actualA;
mockClass.mockMethod(actualA = withCapture()); times = 1;
Assert.assertNotNull("Should not be null", actualA);
Assert.assertEquals(actualA, expectedA);
...
..
}};
}
For void method mocking You can make Expectations without any result as shown below :
#Tested
private MyClassToBeTested myClassToBeTested;
#Injectable
private MockClass mockClass;
#Test
public void test() {
new Expectations() {{
mockClass.mockMethod(anyString);
}};
String inputA = "testValueA";
String inputB = "testValueB";
boolean result = myClassToBeTested.testMethod(inputA, inputB);
assertEquals(true, result);
}