How to make Unit test passed with use Mockito? - java

How I understand Mockito.mock create the stub of the service (or another object).
I have simple handler:
public class Handler
{
private HttpSender sender;
public Handler(BigInteger sessiongId) {
RequestHelper helper = RequestHelper.getInstance();
String requestAsText = helper.getCurrentRequest(sessiongId);
StringBuilder stringBuilder = new StringBuilder(requestAsText);
run(stringBuilder);
sender = SenderGenerator.getInstance().create(stringBuilder.toString());
}
public void run(StringBuilder str) {
str.delete(0, 2);
}
}
How I can pass test for this handler with use Mockito?
public class HandlerTest
{
#Test
public void testRun()
{
StringBuilder str = new StringBuilder("1234");
Handler handler = Mockito.mock(Handler.class);
handler.run(str);
Assert.assertEquals("34", str);
}
}
The actual result of this test is 1234 ? Why ?

Because your haldler object in the test method is a mock-object and not a real object the method call handler.run(str) will not do anything as long as you don't tell it what to do.
So a solution would be to tell the mock object to call the real method like this:
public class HandlerTest {
#Test
public void testRun() {
StringBuilder str = new StringBuilder("1234");
Handler handler = Mockito.mock(Handler.class);
when(handler.run(any(StringBuilder.class))).thenCallRealMethod();
handler.run(str);
Assert.assertEquals("34", str.toString());//add toString here, because you are comparing a String to a StringBuilder
}
}
Another way of testing this method would be to make it static so you dont even need to mock anything:
public class Handler {
public Handler(BigInteger sessiongId) {
//...
}
public static void run(StringBuilder str) {
str.delete(0, 2);
}
}
And your test method would look like this:
public class HandlerTest {
#Test
public void testRun() {
StringBuilder str = new StringBuilder("1234");
Handler.run(str);
Assert.assertEquals("34", str.toString());
}
}

Two things:
1. You have mocked the very class you want to test. And you haven't defined any specific behaviour for the mock either. So the call to the test method itself is skipped. You may have to think over what was the purpose of mocking?
2. You are comparing a StringBuilder object with a String, that needs to be corrected too.

Related

Mock or override static method to test a class

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?

How do I test Function's code when it's passed as method parameter?

Is it possible to test code that is written in lambda function that is passed inside the method process?
#AllArgsConstructor
public class JsonController {
private final JsonElementProcessingService jsonElementProcessingService;
private final JsonObjectProcessingService jsonObjectProcessingService;
private final JsonArrayProcessingService jsonArrayProcessingService;
public void process(String rawJson) {
jsonElementProcessingService.process(json -> {
JsonElement element = new JsonParser().parse(json);
if (element.isJsonArray()) {
return jsonArrayProcessingService.process(element.getAsJsonArray());
} else {
return jsonObjectProcessingService.process(element.getAsJsonObject());
}
}, rawJson);
}
}
Since the lambda is lazy the function is not invoked (Function::apply) when I call JsonController::process so is there any way to check that jsonArrayProcessingService::process is called?
#RunWith(JMockit.class)
public class JsonControllerTest {
#Injectable
private JsonElementProcessingService jsonElementProcessingService;
#Injectable
private JsonObjectProcessingService jsonObjectProcessingService;
#Injectable
private JsonArrayProcessingService jsonArrayProcessingService;
#Tested
private JsonController jsonController;
#Test
public void test() {
jsonController.process("[{\"key\":1}]");
// how check here that jsonArrayProcessingService was invoked?
}
}
Just make it testable (and readable) by converting it to a method:
public void process(String rawJson) {
jsonElementProcessingService.process(this::parse, rawJson);
}
Object parse(String json) {
JsonElement element = new JsonParser().parse(json);
if (element.isJsonArray()) {
return jsonArrayProcessingService.process(element.getAsJsonArray());
} else {
return jsonObjectProcessingService.process(element.getAsJsonObject());
}
}
The relevant guiding principles I personally follow are:
anytime my lambdas require curly brackets, convert them to a method
organise code so that it can be unit tested
You may need to change the return type of the parse method to match whatever your processing services (which you didn’t show) return.
Given its relatively-basic redirection logic, don't you just want to confirm which of the #Injectables got called:
#Test
public void test() {
jsonController.process("[{\"key\":1}]");
new Verifications() {{
jsonArrayProcessingService.process(withInstanceOf(JsonArray.class));
}};
}

Mockito ArgumentCaptor does not return any values on verification

I am trying to use argument capture to determine what arguments are being passed to a mocked Mockito method, but I am not able to capture any values.
class CombinedEvent
{
final List<String> events;
public CombinedEvent() {
this.events = new ArrayList<>();
this.events.add("WATCHITM");
this.events.add("BIDITEM");
}
}
Holder class
class CombinedNotificationAdapter {
private CombinedEvent combinedEvent;
CombinedNotificationAdapter() {
this.combinedEvent = new CombinedEvent();
}
public boolean isEnabled(String user, NotificationPreferenceManager preferenceManager) {
boolean status = true;
for (String event : combinedEvent.events) {
status = status && preferenceManager.isEventEnabled(user, event);
}
return status;
}
}
My unit test
#RunWith(JUnit4.class)
class CombinedNotificationAdapterTest {
private CombinedNotificationAdapter adapter;
#Mock
private NotificationPreferenceManager preferenceManager;
#Before
public void setUp() {
MockitoAnnotations.initMocks(this);
adapter = new CombinedNotificationAdapter();
}
#Test
public void testIsEnabled() {
doReturn(true).when(preferenceManager).isEventEnabled(eq("test"), anyString());
Assert.assertTrue(adapter.isEnabled("test", preferenceManager));
ArgumentCaptor<String> captor = ArgumentCaptor.forClass(String.class);
verify(preferenceManager, times(2)).isEventEnabled(eq("test"), captor.capture());
System.out.println(captor.getAllValues());
}
}
The output of captor.getAllValues() is an empty list. I would like the values to return a list of WATCHITM and BIDITEM. I don't know what I am going wrong.
Reference:
https://static.javadoc.io/org.mockito/mockito-core/2.28.2/org/mockito/Mockito.html#15
https://static.javadoc.io/org.mockito/mockito-core/2.6.9/org/mockito/ArgumentCaptor.html
I think you are overdoing:
doReturn(true)
. when(preferenceManager)
.isEventEnabled(eq("test"), anyString()):
You are scrubbing that expected method invocation and then combining that with your argument captor. And that does not work. You can either stub or capture, not both things! See this existing question for example.
My suggestion: look at this answer and learn how to create your own Answer object. Those get passed an instance of InvocationOnMock. And that class allows you to check the arguments passed into the mocked calls, too!

Mockito: Spying calls within the constructor (Java) [duplicate]

This question already has answers here:
Test class with a new() call in it with Mockito
(7 answers)
Closed 5 years ago.
This is not a duplicate of Test class with a new() call in it with Mockito. I'm trying to write a test to verify that certain methods are being called within the constructor of my spy object (mockToyFacade).
The class under test is ToyFactoryFacade. The idea is clients interact with the ToyFactoryFacade (which wraps a ToyFactory) to generate ToyFacades, which itself is a wrapper around the Toy object.
What I am trying to verify with Mockito?
I want to verify that addToyName(toyName) and addCreationTime(creationTimestamp) are being called on the ToyFacade. Both of these methods are called in the constructor of the ToyFacade.
What's the issue?
When I try to spy the ToyFacade, and verify that both aforementioned methods are called, I receive an error, which says "Actually, there were zero interactions with this mock." When I call the methods separately (i.e., not via the constructor), the verification check out correctly. I'm not sure what I'm doing incorrectly.
Test Code
public class ToyFactoryFacadeTest {
private Toy mockToy;
private ToyFacade mockToyFacade;
// System under test.
private ToyFactoryFacade toyFactoryFacade;
private ToyFactory mockToyFactory;
#Before
public void setup() {
mockToy = mock(Toy.class);
mockToyFacade = spy(new ToyFacade(mockToy, "Phone", System.currentTimeMillis()));
mockToyFactory = mock(ToyFactory.class);
toyFactoryFacade = new ToyFactoryFacade(mockToyFactory) {
#Override
public Toy getToyFacade(String toyName, long creationTimestamp){
return mockToyFacade;
}
};
}
#Test
public void testToyFactoryFacade() {
toyFactoryFacade.initializeAndGetToy("Phone", System.currentTimeMillis());
verify(mockToyFacade).addToyName("Phone");
verify(mockToyFacade).addCreationTime(anyLong());
}
}
Source Code
public class ToyFactoryFacade {
private final ToyFactory toyFactory;
public ToyFactoryFacade(ToyFactory toyFactory) {
this.toyFactory = toyFactory;
}
public ToyFacade initializeAndGetToy(String toyName, long creationTimestamp)
{
getToyFacade(toyName, creationTimestamp);
}
// For testing.
protected ToyFacade getToyFacade(String toyName, long creationTimestamp
{
return new ToyFacade(toyFactory.newToy(), toyName, creationTimestamp);
}
}
public class ToyFactory {
public Toy newToy() {
return new Toy();
}
}
public class ToyFacade {
private final Toy toy;
public ToyFacade(Toy toy, String toyName, long creationTimeStamp) {
this.toy = toy;
addToyName(toyName);
addCreationTime(creationTimestamp);
}
public void addToyName(String name) {
toy.addToyName(toyName);
}
public void addCreationTime(long timestamp) {
toy.addCreationTime(timestamp);
}
}
public class Toy {
public String toyName;
public String creationTimestamp;
public void addToyName(String name) {
toyName = name;
}
public void addCreationTime(long timestamp) {
creationTimestamp = timestamp;
}
}
Your test isn't doing what you expect because the method calls that you're trying to verify have already taken place before you create your spy. What you really want to do is to test the effect of those two method calls, rather than the calls themselves. This would look something like
verify(mockToy).addToyName("Phone");
verify(mockToy).addCreationTime(timestamp);
where timestamp is whatever you pass in in the setUp method.

Mocking a constructor inside a static method

Following is the code I am trying to unit test
public final class ClassToBeTested {
public static void function(String arg) {
ProcessBuilder pb = new ProcessBuilder(arg);
//Using pb here
}
}
I want to mock the constructor invocation (new File(arg)), here
I tried using Power Mock :
#PrepareForTest({ClassToBeTested.class})
public class TestClass {
#Test
public void functionTest() throws Exception {
String str = "abc";
ProcessBuilder mockProcessBuilder = PowerMock.createMock(ProcessBuilder.class);
PowerMock.expectNew(ProcessBuilder.class, str).andReturn(mockProcessBuilder);
PowerMock.replay(mockProcessBuilder, ProcessBuilder.class);
ClassToBeTested.function(abc);
}
}
This doesn't seem to work. As new ProcessBuilder(arg) is not returning the mocked object.
Adding #RunWith(PowerMockRunner.class) helped to resolve the issue.
Also using PowerMock.replayAll().

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