I can’t figure out how I can block the call to the B setTitle method so that it does nothing, but for example just output to the console (output from the system)?
In method B setTitle an error appears, but I want the tests to be independent and the error to be in the class with the test for B
#Component
class B {
public setTitle(String s){
...
}
}
#Service
class A {
#Autowired
private B b;
public getTitle(String s){
b.setTitle(s);
}
}
class ATest {
#Autowired
private class A;
#Test
void getTitleTest() {
//TODO how to override the call class B getTitle
}
}
First off, note that there is a lot of issues with what you have posted here.
You have methods declared without return types, getters that perform mutations, and trying to Autowire private class.
To answer your question, what you want to do is create a Mock and run this with a MockRunner.
Here is a test that will verify the method in your class B was invoked as you expected.
import org.junit.Test;
import org.junit.runner.RunWith;
import org.mockito.InjectMocks;
import org.mockito.Mock;
import org.mockito.Mockito;
import org.mockito.junit.MockitoJUnitRunner;
#RunWith(MockitoJUnitRunner.class)
public class ATest {
#Mock
private B b;
#InjectMocks
private A a;
#Test
public void getTitleTest() {
a.getTitle("soemthing");
Mockito.verify(b).setTitle("soemthing");
}
}
If you indeed want it to print something to the console, you can change the test method by capturing the argument to the method and simply printing it out, like this:
#Test
public void titleTester() {
ArgumentCaptor<String> stringArgumentCaptor = ArgumentCaptor.forClass(String.class);
doNothing().when(b).setTitle(stringArgumentCaptor.capture());
a.getTitle("soemthing");
System.out.println(stringArgumentCaptor.getValue());
}
Related
I have a class which I would like to test with a public method that calls private one. I'd like to assume that private method works correctly. For example, I'd like something like doReturn....when.... I found that there is possible solution using PowerMock, but this solution doesn't work for me.
How It can be done? Did anybody have this problem?
I don't see a problem here. With the following code using the Mockito API, I managed to do just that :
public class CodeWithPrivateMethod {
public void meaningfulPublicApi() {
if (doTheGamble("Whatever", 1 << 3)) {
throw new RuntimeException("boom");
}
}
private boolean doTheGamble(String whatever, int binary) {
Random random = new Random(System.nanoTime());
boolean gamble = random.nextBoolean();
return gamble;
}
}
And here's the JUnit test :
import org.junit.Test;
import org.junit.runner.RunWith;
import org.powermock.api.mockito.PowerMockito;
import org.powermock.core.classloader.annotations.PrepareForTest;
import org.powermock.modules.junit4.PowerMockRunner;
import static org.mockito.Matchers.anyInt;
import static org.mockito.Matchers.anyString;
import static org.powermock.api.mockito.PowerMockito.when;
import static org.powermock.api.support.membermodification.MemberMatcher.method;
#RunWith(PowerMockRunner.class)
#PrepareForTest(CodeWithPrivateMethod.class)
public class CodeWithPrivateMethodTest {
#Test(expected = RuntimeException.class)
public void when_gambling_is_true_then_always_explode() throws Exception {
CodeWithPrivateMethod spy = PowerMockito.spy(new CodeWithPrivateMethod());
when(spy, method(CodeWithPrivateMethod.class, "doTheGamble", String.class, int.class))
.withArguments(anyString(), anyInt())
.thenReturn(true);
spy.meaningfulPublicApi();
}
}
A generic solution that will work with any testing framework (if your class is non-final) is to manually create your own mock.
Change your private method to protected.
In your test class extend the class
override the previously-private method to return whatever constant you want
This doesn't use any framework so its not as elegant but it will always work: even without PowerMock. Alternatively, you can use Mockito to do steps #2 & #3 for you, if you've done step #1 already.
To mock a private method directly, you'll need to use PowerMock as shown in the other answer.
For some reason Brice's answer is not working for me. I was able to manipulate it a bit to get it to work. It might just be because I have a newer version of PowerMock. I'm using 1.6.5.
import java.util.Random;
public class CodeWithPrivateMethod {
public void meaningfulPublicApi() {
if (doTheGamble("Whatever", 1 << 3)) {
throw new RuntimeException("boom");
}
}
private boolean doTheGamble(String whatever, int binary) {
Random random = new Random(System.nanoTime());
boolean gamble = random.nextBoolean();
return gamble;
}
}
The test class looks as follows:
import org.junit.Test;
import org.junit.runner.RunWith;
import org.powermock.api.mockito.PowerMockito;
import org.powermock.core.classloader.annotations.PrepareForTest;
import org.powermock.modules.junit4.PowerMockRunner;
import static org.mockito.Matchers.anyInt;
import static org.mockito.Matchers.anyString;
import static org.powermock.api.mockito.PowerMockito.doReturn;
#RunWith(PowerMockRunner.class)
#PrepareForTest(CodeWithPrivateMethod.class)
public class CodeWithPrivateMethodTest {
private CodeWithPrivateMethod classToTest;
#Test(expected = RuntimeException.class)
public void when_gambling_is_true_then_always_explode() throws Exception {
classToTest = PowerMockito.spy(classToTest);
doReturn(true).when(classToTest, "doTheGamble", anyString(), anyInt());
classToTest.meaningfulPublicApi();
}
}
i know a way ny which you can call you private function to test in mockito
#Test
public void commandEndHandlerTest() throws Exception
{
Method retryClientDetail_privateMethod =yourclass.class.getDeclaredMethod("Your_function_name",null);
retryClientDetail_privateMethod.setAccessible(true);
retryClientDetail_privateMethod.invoke(yourclass.class, null);
}
With no argument:
ourObject = PowerMockito.spy(new OurClass());
when(ourObject , "ourPrivateMethodName").thenReturn("mocked result");
With String argument:
ourObject = PowerMockito.spy(new OurClass());
when(ourObject, method(OurClass.class, "ourPrivateMethodName", String.class))
.withArguments(anyString()).thenReturn("mocked result");
Something to Consider
Make sure the private function is calling another public function and you can proceed only mocking the public function.
I have a class which I would like to test with a public method that calls private one. I'd like to assume that private method works correctly. For example, I'd like something like doReturn....when.... I found that there is possible solution using PowerMock, but this solution doesn't work for me.
How It can be done? Did anybody have this problem?
I don't see a problem here. With the following code using the Mockito API, I managed to do just that :
public class CodeWithPrivateMethod {
public void meaningfulPublicApi() {
if (doTheGamble("Whatever", 1 << 3)) {
throw new RuntimeException("boom");
}
}
private boolean doTheGamble(String whatever, int binary) {
Random random = new Random(System.nanoTime());
boolean gamble = random.nextBoolean();
return gamble;
}
}
And here's the JUnit test :
import org.junit.Test;
import org.junit.runner.RunWith;
import org.powermock.api.mockito.PowerMockito;
import org.powermock.core.classloader.annotations.PrepareForTest;
import org.powermock.modules.junit4.PowerMockRunner;
import static org.mockito.Matchers.anyInt;
import static org.mockito.Matchers.anyString;
import static org.powermock.api.mockito.PowerMockito.when;
import static org.powermock.api.support.membermodification.MemberMatcher.method;
#RunWith(PowerMockRunner.class)
#PrepareForTest(CodeWithPrivateMethod.class)
public class CodeWithPrivateMethodTest {
#Test(expected = RuntimeException.class)
public void when_gambling_is_true_then_always_explode() throws Exception {
CodeWithPrivateMethod spy = PowerMockito.spy(new CodeWithPrivateMethod());
when(spy, method(CodeWithPrivateMethod.class, "doTheGamble", String.class, int.class))
.withArguments(anyString(), anyInt())
.thenReturn(true);
spy.meaningfulPublicApi();
}
}
A generic solution that will work with any testing framework (if your class is non-final) is to manually create your own mock.
Change your private method to protected.
In your test class extend the class
override the previously-private method to return whatever constant you want
This doesn't use any framework so its not as elegant but it will always work: even without PowerMock. Alternatively, you can use Mockito to do steps #2 & #3 for you, if you've done step #1 already.
To mock a private method directly, you'll need to use PowerMock as shown in the other answer.
For some reason Brice's answer is not working for me. I was able to manipulate it a bit to get it to work. It might just be because I have a newer version of PowerMock. I'm using 1.6.5.
import java.util.Random;
public class CodeWithPrivateMethod {
public void meaningfulPublicApi() {
if (doTheGamble("Whatever", 1 << 3)) {
throw new RuntimeException("boom");
}
}
private boolean doTheGamble(String whatever, int binary) {
Random random = new Random(System.nanoTime());
boolean gamble = random.nextBoolean();
return gamble;
}
}
The test class looks as follows:
import org.junit.Test;
import org.junit.runner.RunWith;
import org.powermock.api.mockito.PowerMockito;
import org.powermock.core.classloader.annotations.PrepareForTest;
import org.powermock.modules.junit4.PowerMockRunner;
import static org.mockito.Matchers.anyInt;
import static org.mockito.Matchers.anyString;
import static org.powermock.api.mockito.PowerMockito.doReturn;
#RunWith(PowerMockRunner.class)
#PrepareForTest(CodeWithPrivateMethod.class)
public class CodeWithPrivateMethodTest {
private CodeWithPrivateMethod classToTest;
#Test(expected = RuntimeException.class)
public void when_gambling_is_true_then_always_explode() throws Exception {
classToTest = PowerMockito.spy(classToTest);
doReturn(true).when(classToTest, "doTheGamble", anyString(), anyInt());
classToTest.meaningfulPublicApi();
}
}
i know a way ny which you can call you private function to test in mockito
#Test
public void commandEndHandlerTest() throws Exception
{
Method retryClientDetail_privateMethod =yourclass.class.getDeclaredMethod("Your_function_name",null);
retryClientDetail_privateMethod.setAccessible(true);
retryClientDetail_privateMethod.invoke(yourclass.class, null);
}
With no argument:
ourObject = PowerMockito.spy(new OurClass());
when(ourObject , "ourPrivateMethodName").thenReturn("mocked result");
With String argument:
ourObject = PowerMockito.spy(new OurClass());
when(ourObject, method(OurClass.class, "ourPrivateMethodName", String.class))
.withArguments(anyString()).thenReturn("mocked result");
Something to Consider
Make sure the private function is calling another public function and you can proceed only mocking the public function.
I´m using google guice to inject this class example
class A {
String a;
}
Then is injected in my class B
class B {
#Inject A aInstance;
public void checkValue(){
System.out.println(aInstance.a);
}
}
Maybe using aspectJ, but what I would like is, that one test of mine, would get this A instance and would set the "a" string as "foo", before execute the test that cover the B class, so when the B class invoke checkValue this one would print "foo"
You mention the word test in your question - if you are writing a jUnit test for B you could perform the injection in an #Before clause, as demonstrated here.
private Injector injector;
#Before
public void init() throws Exception {
injector = Guice.createInjector(new AbstractModule() {
#Override
protected void configure() {
bind(A.class).to(MockedInstanceOfAWithValueFoo.class);
}
});
}
You could also call
bind(A.class).toInstance(new MockedInstanceOfAWithValueFoo());
If we assume that A has a constructor by which we can define A.a, the mocked instance could look like this:
public class MockedInstanceOfAWithValueFoo extends A{
public MockedInstanceOfAWithValueFoo() {
super("foo");
}
}
Again, you could make your mocked class accept the value of A.a through a constructor to make the creation of B (and the associated value of A.a) more dynamic.
With Mockito:
import static org.junit.Assert.assertNotNull;
import static org.mockito.Mockito.when;
import org.junit.Before;
import org.junit.Test;
import org.mockito.InjectMocks;
import org.mockito.Mock;
import org.mockito.MockitoAnnotations;
public class MyTest {
#Mock
A mockA;
#InjectMocks
B mockB;
#Before
public void init() {
MockitoAnnotations.initMocks(this);
mockA.a = "Foo";
//when(mockA.getA()).thenReturn("Foo"); //if you use getter
}
#Test
public void myTest() {
assertNotNull(mockA);
assertNotNull(mockA.a);
assertNotNull(mockB);
assertNotNull(mockB.ainstance);
mockB.checkValue();
}
}
Here's my problem in detail.
Setup:
I have class A that has a private member variable of class B.
A method(method1) in class A calls a non-static method(method2)
in class B.
Class B actually inherits method2 from a protected abstract class C and does not override it.
Problem:
I'm writing a test for class A.
In the test I'm mocking the call to method2.
Sample Code:
B b = Mockito.mock(B.class);
A a = new A(b);
Mockito.when(b.method2()).thenReturn(MY_LIST);
Now when I call method1(which in turn calls method2), I get a
NullPointerException.
Sample Code:
a.method1();
I'm assuming that this call is completely independent of the implementation of method2 since I'm mocking it. Is that wrong ? If not, what am I doing wrong ?
PS: class C is protected and Class A is in a different package from class B and C.
I see that you are using Mockito in your test. I have recently used it on a project and I did a test project with the following.
First a service (A) with uses another class (B).
public class Service {
private NonStaticClass nonStatic;
public NonStaticClass getNonStatic() {
return nonStatic;
}
public void setNonStatic(NonStaticClass nonStatic) {
this.nonStatic = nonStatic;
}
public int useStaticService () {
return 2*StaticClass.staticMethod();
}
public Integer getLastUse () {
return this.nonStatic.getLastUse();
}
}
Then here is the (B) class:
public class NonStaticClass {
private Integer lastUse = new Integer(0);
public Integer getLastUse() {
return lastUse++;
}
}
In order to test everithing is working i created a test for it.
import static org.mockito.Mockito.when;
import junit.framework.Assert;
import org.junit.Before;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.mockito.InjectMocks;
import org.mockito.Mock;
import org.mockito.runners.MockitoJUnitRunner;
#RunWith(MockitoJUnitRunner.class)
public class TestNonStaticMock {
private final Integer staticMethodOutput = 10;
#Mock
NonStaticClass mock = new NonStaticClass();
#InjectMocks
Service service = new Service();
#Before
public void before () {
setMock();
}
private void setMock() {
when(mock.getLastUse()).thenReturn(staticMethodOutput);
}
#Test
public void mockNonStaticMethod () {
Integer result = service.getLastUse();
System.out.println(result.toString());
Assert.assertEquals(staticMethodOutput, result);
}
}
Hope it can be usefull.
I have a class which I would like to test with a public method that calls private one. I'd like to assume that private method works correctly. For example, I'd like something like doReturn....when.... I found that there is possible solution using PowerMock, but this solution doesn't work for me.
How It can be done? Did anybody have this problem?
I don't see a problem here. With the following code using the Mockito API, I managed to do just that :
public class CodeWithPrivateMethod {
public void meaningfulPublicApi() {
if (doTheGamble("Whatever", 1 << 3)) {
throw new RuntimeException("boom");
}
}
private boolean doTheGamble(String whatever, int binary) {
Random random = new Random(System.nanoTime());
boolean gamble = random.nextBoolean();
return gamble;
}
}
And here's the JUnit test :
import org.junit.Test;
import org.junit.runner.RunWith;
import org.powermock.api.mockito.PowerMockito;
import org.powermock.core.classloader.annotations.PrepareForTest;
import org.powermock.modules.junit4.PowerMockRunner;
import static org.mockito.Matchers.anyInt;
import static org.mockito.Matchers.anyString;
import static org.powermock.api.mockito.PowerMockito.when;
import static org.powermock.api.support.membermodification.MemberMatcher.method;
#RunWith(PowerMockRunner.class)
#PrepareForTest(CodeWithPrivateMethod.class)
public class CodeWithPrivateMethodTest {
#Test(expected = RuntimeException.class)
public void when_gambling_is_true_then_always_explode() throws Exception {
CodeWithPrivateMethod spy = PowerMockito.spy(new CodeWithPrivateMethod());
when(spy, method(CodeWithPrivateMethod.class, "doTheGamble", String.class, int.class))
.withArguments(anyString(), anyInt())
.thenReturn(true);
spy.meaningfulPublicApi();
}
}
A generic solution that will work with any testing framework (if your class is non-final) is to manually create your own mock.
Change your private method to protected.
In your test class extend the class
override the previously-private method to return whatever constant you want
This doesn't use any framework so its not as elegant but it will always work: even without PowerMock. Alternatively, you can use Mockito to do steps #2 & #3 for you, if you've done step #1 already.
To mock a private method directly, you'll need to use PowerMock as shown in the other answer.
For some reason Brice's answer is not working for me. I was able to manipulate it a bit to get it to work. It might just be because I have a newer version of PowerMock. I'm using 1.6.5.
import java.util.Random;
public class CodeWithPrivateMethod {
public void meaningfulPublicApi() {
if (doTheGamble("Whatever", 1 << 3)) {
throw new RuntimeException("boom");
}
}
private boolean doTheGamble(String whatever, int binary) {
Random random = new Random(System.nanoTime());
boolean gamble = random.nextBoolean();
return gamble;
}
}
The test class looks as follows:
import org.junit.Test;
import org.junit.runner.RunWith;
import org.powermock.api.mockito.PowerMockito;
import org.powermock.core.classloader.annotations.PrepareForTest;
import org.powermock.modules.junit4.PowerMockRunner;
import static org.mockito.Matchers.anyInt;
import static org.mockito.Matchers.anyString;
import static org.powermock.api.mockito.PowerMockito.doReturn;
#RunWith(PowerMockRunner.class)
#PrepareForTest(CodeWithPrivateMethod.class)
public class CodeWithPrivateMethodTest {
private CodeWithPrivateMethod classToTest;
#Test(expected = RuntimeException.class)
public void when_gambling_is_true_then_always_explode() throws Exception {
classToTest = PowerMockito.spy(classToTest);
doReturn(true).when(classToTest, "doTheGamble", anyString(), anyInt());
classToTest.meaningfulPublicApi();
}
}
i know a way ny which you can call you private function to test in mockito
#Test
public void commandEndHandlerTest() throws Exception
{
Method retryClientDetail_privateMethod =yourclass.class.getDeclaredMethod("Your_function_name",null);
retryClientDetail_privateMethod.setAccessible(true);
retryClientDetail_privateMethod.invoke(yourclass.class, null);
}
With no argument:
ourObject = PowerMockito.spy(new OurClass());
when(ourObject , "ourPrivateMethodName").thenReturn("mocked result");
With String argument:
ourObject = PowerMockito.spy(new OurClass());
when(ourObject, method(OurClass.class, "ourPrivateMethodName", String.class))
.withArguments(anyString()).thenReturn("mocked result");
Something to Consider
Make sure the private function is calling another public function and you can proceed only mocking the public function.