passing Parameterized input using Mockitos - java

I am using Mockito for unit testing. I am wondering if its possible to send Parametrized input parameters with as in Junit testing
e.g
#InjectMocks
MockClass mockClass = new MockClass();
#Test
public void mockTestMethod()
{
mockClass.testMethod(stringInput);
// here I want to pass a list of String inputs
// this is possible in Junit through Parameterized.class..
// wondering if its can be done in Mockito
}

In JUnit, Parameterized tests use a special runner that ensure that the test is instantiated multiple times, so each test method is called multiple times. Mockito is a tool for writing specific unit tests, so there is no built-in ability to run the same test multiple times with different Mockito expectations.
If you want your test conditions to change, your best bet is to do one of the following:
Parameterize your test using JUnit, with a parameter for the mock inputs you want;
Run a loop of different parameters in your test, which unfortunately avoids the "test one thing per method" philosophy
Extract a method that actually performs the test, and create a new #Test method for each mock you want.
Note that there's no prohibition on using mock objects as #Parameterized test parameters. If you're looking to parameterize based on mocks, you can do that, possibly creating the mock and setting the expectations in a static method on the test.
Note about runners: This Parameterized test runner conflicts with Mockito's MockitoJUnitRunner: Each test class can only have one runner. You'll want to switch to #Before and #After methods or a Mockito JUnit4 rule for your setup, if you use them both.
As an example, compressed from a different answer that explains more about Parameterized runners versus JUnit rules and lifting from the JUnit4 Parameterized Test doc page and MockitoRule doc page:
#RunWith(Parameterized.class)
public class YourComponentTest {
#Rule public MockitoRule rule = MockitoJUnit.rule();
#Mock YourDep mockYourDep;
#Parameters public static Collection<Object[]> data() { /* Return the values */ }
public YourComponentTest(Parameter parameter) { /* Save the parameter to a field */ }
#Test public void test() { /* Use the field value in assertions */ }
}

If you are stuck with an older version of mockito where MockitoRule isn't available, the other possibility is to initialize the mocks explicitely with MockitoAnnotations.initMocks:
#RunWith(Parameterized.class)
public class YourComponentTest {
#Mock YourDep mockYourDep;
#Parameter
public Parameter parameter;
#Parameters public static Collection<Object[]> data() { /* Return the values */ }
#Before
public void init() {
MockitoAnnotations.initMocks(this);
}
#Test public void test() { /* Use the field value in assertions */ }
}

You can use the JUnitParamsRunner. Here's how I do it:
import junitparams.JUnitParamsRunner;
import junitparams.Parameters;
import org.junit.Before;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.mockito.InjectMocks;
import org.mockito.Mock;
import java.util.Arrays;
import static org.hamcrest.CoreMatchers.is;
import static org.hamcrest.MatcherAssert.assertThat;
import static org.mockito.Mockito.when;
import static org.mockito.MockitoAnnotations.initMocks;
#RunWith(value = JUnitParamsRunner.class)
public class ParameterizedMockitoTest {
#InjectMocks
private SomeService someService;
#Mock
private SomeOtherService someOtherService;
#Before
public void setup() {
initMocks(this);
}
#Test
#Parameters(method = "getParameters")
public void testWithParameters(Boolean parameter, Boolean expected) throws Exception {
when(someOtherService.getSomething()).thenReturn(new Something());
Boolean testObject = someService.getTestObject(parameter);
assertThat(testObject, is(expected));
}
#Test
public void testSomeBasicStuffWithoutParameters() {
int i = 0;
assertThat(i, is(0));
}
public Iterable getParameters() {
return Arrays.asList(new Object[][]{
{Boolean.TRUE, Boolean.TRUE},
{Boolean.FALSE, Boolean.FALSE},
});
}
}

What solved it for me was:
Class level annotation of #ExtendWith(MockitoExtension.class)
Annotate each mock object with #Mock
#InjectMocks on the test class. Or a setup method annotated with #BeforeEach where you initialise the class to be tested.
if you need the #test annotation, make sure you import org.junit.jupiter.api.Test. org.junit.test will not work!
I'm using mockito version 4.

Related

Mockito when not resetting between Tests [duplicate]

I am seeing behaviour that I believe is a bug. #InjectMocks does not seem to create a new test subject before every test method. Where as #Mock does. In the following example, if Subject.section is final one #Test fails. If its not final both pass. My current workaround is to use #BeforeClass, but this is not ideal.
Subject.java:
package inject_mocks_test;
public class Subject {
private final Section section;
public Subject(Section section) {
this.section = section;
}
public Section getSection() {
return section;
}
}
Section.java:
package inject_mocks_test;
public class Section {}
SubjectTest.java
package inject_mocks_test;
import org.mockito.InjectMocks;
import org.mockito.Mock;
import org.mockito.MockitoAnnotations;
import org.testng.annotations.BeforeMethod;
import org.testng.annotations.Test;
import static org.testng.Assert.assertEquals;
public class SubjectTest {
#Mock
Section section;
#InjectMocks
Subject subject;
#BeforeMethod
public void setup() {
MockitoAnnotations.initMocks(this);
}
#Test
public void test1() {
assertEquals(section, subject.getSection());
}
#Test
public void test2() {
assertEquals(section, subject.getSection());
}
}
Cheers.
You are using the #InjectMocks for constructor incjection. This will work as long as Mockito finds the field not initalized (null). JUnit is creating a new instance of the test class before each test, so JUnit fans (like me) will never face such problem. TestNg is not creating a new instance of test class. It's keeping the state between test methods, so when MockitoAnnotations.initMocks(this) is called for the second time, Mockito will find subject field already initialized and will try to use field injection. This on the other turn will work until the field is not final.
Is this is a bug? I believe not - rather a natural consequence of the API design.
Some workaround for you would be to add
this.subject = null;
in some #AfterMethod method.

How to run PowerMock on dynamically created TestCase

I was trying to mock my test suites. My test framework creates test cases by scanning test files on disk. So each time the test cases are dynamically created.
I was trying to use PowerMock. Below is the thing I tried first.
public class GroupTestcase_T extends TestSuite {
static void run() {
scan();
junit.textui.TestRunner.run(g);
}
static void scan() {
// scan disk
for (MyTestCase t : tests) { addTest(t); }
}
}
#RunWith(PowerMockRunner.class)
#PrepareForTest(ClassToStub.class)
public class MyTestCase extends TestCase {
public MyTestCase(TestInfo info) {...}
#Override
protected void setUp() throws Exception {
PowerMockito.mockStatic(ClassToStub.class);
when(ClassToStub.methodToStub())
.thenReturn(new FakeProxy());
}
#Test
public void test() throws Exception {
// Test!
}
}
Above code seems not working:
Also, this error might show up because:
1. you stub either of: final/private/equals()/hashCode() methods.
Those methods cannot be stubbed/verified.
2. inside when() you don't call method on mock but on some other object.
3. the parent of the mocked class is not public.
It is a limitation of the mock engine.
I traced the code and found that PowerMockRunner are not called at all.
Also I tried manually force Junit to run it with PowerMockRunner:
Result result = junit.run(new PowerMockRunner(MyTestCase.class));
PowerMockRunner has only one constructor that takes the test class as parameter. My test cases are different each time but all share the same class.
Any idea how to use PowerMock if TestCase are dynamically created?
I was using Junit 4 / PowerMock 1.5
You can generate your tests with the parameterized tests feature and apply the #PowerMockRule.
import static org.junit.Assert.assertTrue;
import java.util.Arrays;
import java.util.Collection;
import org.junit.Rule;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.junit.runners.Parameterized;
import org.junit.runners.Parameterized.Parameters;
import org.powermock.api.mockito.PowerMockito;
import org.powermock.core.classloader.annotations.PrepareForTest;
import org.powermock.modules.junit4.rule.PowerMockRule;
#RunWith(Parameterized.class)
#PrepareForTest(ClassToStub.class)
public class MyTestCase{
#Parameters
public static Collection<Object[]> scan() {
return Arrays.asList(new Object[][] {
{ new TestInfo() }, { new TestInfo() } });
}
#Rule
public PowerMockRule rule = new PowerMockRule();
public MyTestCase(TestInfo info) {
// ...
}
#Test
public void test() throws Exception {
PowerMockito.mockStatic(ClassToStub.class);
PowerMockito.when(ClassToStub.methodToStub()).thenReturn(new FakeProxy());
assertTrue(ClassToStub.methodToStub() instanceof FakeProxy);
}
}
Beware, in your example, you are mixing junit 3 (extends TestSuite, protected setUp) and junit 4 (#Test) test definitions.

How to parameterize junit Test Suite

Is it possible to parameterize a TestSuite in junit 4 ?
For declaring a class as a test suite I need the annotation #RunWith(Suite.class), but the same annotation is also needed to declare the test as parameterized: #RunWith(Parameterized.class) so I cannot add both to the same class.
I found a similar question in this site that did not help much. So far, all the examples I have found explain how to parameterize simple unit tests, not a complete test tuite.
I believe the basic answer is No, because as you said, the #RunsWith only take one parameter. I found a blog posting that got a bit creative in how to handle this situation.
We don't use the parameterized tests, but may you could create a separate suite like we do that only lists the test classes and the parameterized test could be part of that. I modified our test suite to include a parameterized test class to part of the suite and it ran fine. We create our suite like below where PrimeNumberCheckerTest was a simple I pulled from the web.
package com.jda.portfolio.api.rest.server;
import org.junit.runner.RunWith;
import org.junit.runners.Suite;
import org.junit.runners.Suite.SuiteClasses;
#RunWith(Suite.class)
#SuiteClasses({ com.mycompany.api.rest.server.resource.TestCartResourceJava.class,
com.mycompany.api.rest.server.resource.TestCustomerResource.class,
com.mycompany.api.rest.server.resource.TestWizardProfileResource.class,
com.mycompany.api.rest.server.interceptor.TestBaseSearchInterceptor.class,
com.mycompany.api.rest.server.resource.TestQueryParameters.class,
com.mycompany.api.rest.server.expression.TestCartExpressionGenerator.class,
com.mycompany.api.rest.server.expression.TestPreferenceExpressionGenerator.class,
com.mycompany.api.rest.server.PrimeNumberCheckerTest.class,
})
public class AllTests {}
Here's the source for the parameterized test case;
package com.jda.portfolio.api.rest.server:
import static org.junit.Assert.*;
import java.util.Arrays;
import java.util.Collection;
import org.junit.Before;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.junit.runners.Parameterized;
import org.junit.runners.Suite.SuiteClasses;
#RunWith(Parameterized.class)
#SuiteClasses({PrimeNumberCheckerTest.class})
public class PrimeNumberCheckerTest {
private Integer inputNumber;
private Boolean expectedResult;
private PrimeNumberChecker primeNumberChecker;
#Before
public void initialize() {
primeNumberChecker = new PrimeNumberChecker();
}
// Each parameter should be placed as an argument here
// Every time runner triggers, it will pass the arguments
// from parameters we defined in primeNumbers() method
public PrimeNumberCheckerTest(Integer inputNumber,
Boolean expectedResult) {
this.inputNumber = inputNumber;
this.expectedResult = expectedResult;
}
#Parameterized.Parameters
public static Collection primeNumbers() {
return Arrays.asList(new Object[][] {
{ 2, true },
{ 6, false },
{ 19, true },
{ 22, false },
{ 23, true }
});
}
// This test will run five times since we have as many parameters defined
#Test
public void testPrimeNumberChecker() {
System.out.println("Parameterized Number is : " + inputNumber);
assertEquals(expectedResult,
primeNumberChecker.validate(inputNumber));
}
I was able to parameterize a test suite and use its data in a test class member of the suite as follows:
In JUTsuite:
#RunWith(Suite.class)
#Suite.SuiteClasses({
JUT_test1.class,
})
public class JUTSuite{
// Declare all variables/objects you want to share with the test classes, e.g.
protected static List<Fx> globalFxs;
// This is the data list we'll use as parameters
protected static List<Dx> globalDxs;
#Parameters
public static Collection<Object[]> data(){
// Instantiate object list for parameters.
// Note: you must do it here and not in, say, #BeforeClass setup()
// e.g.
globalDxs=new ArrayList<Dx>(serverObj.values());
Collection<Object[]> rows=new ArrayList<Object[]>();
for(Dx d:globalDxs) {
rows.add(new Object[]{d});
}
return rows;
}
#BeforeClass
public static void setUp() throws Exception {
// Instantiate/initialize all suite variables/objects to be shares with test classes
// e.g. globalFxs=new ArrayList<Fx>();
}
#AfterClass
public static void tearDown() throws Exception {
// Clean up....
}
}
Next, in test class:
#RunWith(Parameterized.class)
public class JUT_test1 {
// declare local names (if desired) for suite-wide variable/objects
// e.g.
private static List<Fx> globalFxs;
// This is the test parameter:
private Dx d;
public JUT_test1(Dx d){
this.d=d;
}
#Parameters
public static Collection<Object[]> data(){
// Note: we're calling the suite's data() method which has already executed.
return JUTSuite.data();
}
#BeforeClass
public static void setUpBeforeClass() throws Exception {
// (If desired)initialize local variables by referencing suite variables.
// e.g.globalFxs=JUTSuite.globalFxs;
}
}
I agree, it's not possible with the provided classes, but there are workarounds that will get you most of the way there, like #mikemil's.
I've spent some time extending Suite and delegating to Parameterized, with partial success; it is possible to build runner that does what you want, and the code is more-or-less written for you in those two classes. The way those classes interact (in particular, the definition of Parameterized#getChildren()) makes it difficult to extend or delegate to those classes to accomplish what you need, but creating a whole new class than extends ParentRunner and lifts code from the other two would be fairly easy.
I'll try to get more time to come back to this later. If you do build a new runner before I get around to it, please post it as an answer, I'd love to use it myself.
the best solution will be, keep suit classes separately in a blank class.
For example, I am testing logins as Parameterized tests and putting in a suit (for navigation performance measurement)
#RunWith(Suite.class)
#Suite.SuiteClasses({
LoginPageTest.class,
HomePageTests.class})
public class PerformanceTests {
}
and LoginPageTest is actually Parameterizedtests
#RunWith(Parameterized.class)
public class LoginPageTest
{...}
As already stated multiple times, it's not possible to parameterize a test suite with the runners provided by JUnit 4.
Anyway, I wouldn't recommend to make your testclasses dependent from some externally provided state. What if you want to run a single testclass?
I would recommend to make your separate test classes #Parameterized and use a utility class to provide the parameters:
#RunWith(Suite.class)
#SuiteClasses({ Test1.class, Test2.class })
public class TestSuite {
// suite
}
#RunWith(Parameterized.class}
public class Test1 {
public Test1(Object param1) { /* ... */ }
#Parameters
public static Collection<Object[]> data() {
return TestParameters.provideTestData()
}
#Test
public void someTest() { /* ... */ }
}
#RunWith(Parameterized.class}
public class Test2 {
public Test2(Object param1) { /* ... */ }
#Parameters
public static Collection<Object[]> data() {
return TestParameters.provideTestData()
}
#Test
public void someOtherTest() { /* ... */ }
}
class TestParameters {
public static Collection<Object[]> provideTestData() {
Collection<Object[]> data = new ...;
// build testdata
return data;
}
You're right: Both Suite and Parameterized are Runners and only one Runner may be used to run a test at a time. Standard JUnit 4 doesn't provide a combined Runner.
You can either implement your own Runner or have a look at this ready-to-use library which provides a ParameterizedSuite Runner: https://github.com/PeterWippermann/parameterized-suite
A parameterized test suite looks like this:
#RunWith(ParameterizedSuite.class)
#SuiteClasses({OneTest.class, TwoTest.class})
public class MyParameterizedTestSuite {
#Parameters(name = "Parameters are {0} and {1}")
public static Object[] params() {
return new Object[][] {{'A',1}, {'B',2}, {'C',3}};
}
Maybe this answer helps: Parameterized unit test suites
It uses #RunWith(Enclosed.class) and seems to solve the problem.

mockito, spy- not sure how it's done for partial mocking

I have a class, where i want to mock certain methods of the class and test the others. That is the only way i can verity and assert that it's working.
class UnderTest{
public void methodToTest(){
methodToCall1()
methodToCall2()
}
public void methodToCall1(){
}
public void methodToCall2(){
}
}
Now, since i want to test the first method, i want to create a partial mock of UnderTest so i can verify that those two methods were called.
How do i achieve this in Mockito?
Thanks for your help!
You mentioned you wanted to do two things:
1. Create real partial mocks
2. Verify method invocations
However, since your goal is to validate that methodToCall1() and methodToCall2() were actually invoked, all you need to do is spy on the real object. This can be accomplished with the following code block:
//Spy UnderTest and call methodToTest()
UnderTest mUnderTest = new UnderTest();
UnderTest spyUnderTest = Spy(mUnderTest);
spyUnderTest.methodToTest();
//Verify methodToCall1() and methodToCall2() were invoked
verify(spyUnderTest).methodToCall1();
verify(spyUnderTest).methodToCall2();
If one of the methods are not called, for example methodToCall1, an Exception will be thrown:
Exception in thread "main" Wanted but not invoked:
undertest.methodToCall1();
...
package foo;
import static org.mockito.Mockito.verify;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.mockito.Spy;
import org.mockito.runners.MockitoJUnitRunner;
#RunWith(MockitoJUnitRunner.class)
public class FooTest {
#Spy
private UnderTest underTest;
#Test
public void whenMethodToTestExecutedThenMethods1And2AreCalled() {
// Act
underTest.methodToTest();
// Assert
verify(underTest).methodToCall1();
verify(underTest).methodToCall2();
}
}

Do Mock objects get reset for each test?

I'm using the Mockito framework to create Mock objects in my JUnit tests. Each mock knows what methods have been called on it, so during my tests I can write
verify(myMock, atLeastOnce()).myMethod();
I am wondering if this internal mock knowledge of what it has called will persist across my tests? If it does persist, then I could be getting false positives when using the same verify method in two tests.
A code example
#RunWith(MockitoJUnitRunner.class)
public class EmrActivitiesImplTest {
#Mock private MyClass myMock;
#Before
public void setup() {
when(myMock.myMethod()).thenReturn("hello");
}
#Test
public void test1() {
// ..some logic
verify(myMock, atLeastOnce()).myMethod();
}
#Test
public void test2() {
// ..some other logic
verify(myMock, atLeastOnce()).myMethod();
}
}
Mock state is persisted - test2 will pass regardless, since test1's verify method passed
Mock state is reset - test2 will fail if myMock.myMethod() isn't called
JUnit creates a new instance of test class each time it runs a new test method and runs #Before method each time it creates a new test class. You can easily test it:
#Before
public void setup() {
System.out.println("setup");
when(myMock.myMethod()).thenReturn("hello");
}
And MockitoJUnitRunner will create a new MyMock mock instance for every test method.
import org.junit.Before;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.mockito.Mock;
import org.mockito.runners.MockitoJUnitRunner;
import static org.mockito.Mockito.*;
#RunWith(MockitoJUnitRunner.class)
public class sandbox {
#Mock
private MyClass myMock;
#Before
public void setup() {
when(myMock.myMethod()).thenReturn("hello");
}
#Test
public void test1() {
myMock.myMethod();
verify(myMock, times(1)).myMethod();
}
#Test
public void test2() {
myMock.myMethod();
verify(myMock, times(1)).myMethod();
}
}
This passes. If the state persisted then the second test would fail. If you debug it you would see that you get a new instance of the mocked object for each test.
If you just initialize the Mock objects in your setup, then inside each test you can provide different functionality. You can initialize it once and change how they act/expect per test after that.

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