How to run something after all the #Before's have happened? - junit

We're using #Before's all along the hierarchy to get some test data inserted into the database before tests execute. I want to commit all that data to the database just before the #Test starts running.
One way to do this would be to commit the data as the last step in this test class' #Before method. But we have hundreds of such classes, and don't want to go in and modify all of those.
I've played with ExternalResource #Rule and TestWatcher #Rule...but they don't afford a way to hook in after all the #Before's have happened.
I'm thinking I need to look at building a custom TestRunner to do this.
Is that the right track?

What you are looking for, seems inconsistent to me. Settind some data and committing them are very close operations and shouldn't belong to different places. On the contrary, I would rather put them into one function and call it with actual parameters set to values you want to insert. Or use SQL strings as actual parameters. And call this finction from #Before
If you are insisting, there is no problem to do it. Create descendant classes for your Junit classes:
package ...;
import org.junit.Before;
public class NewAndBetterYourTest1 extends YourTest1 {
#Override
#Before
public void setUp() {
super.setUp(); // this is where you are setting everything.
makeCommits();
}
}
Only don't forget to launch these new tests

While you can't do quite what you are asking without a custom Runner, you could ensure that all of the data created in the #Before methods is committed with a Rule:
public class LocalDatabase extends ExternalResource {
private DataSource dataSource;
#Override
protected void before() {
dataSource = createLocalDatabase();
}
#Override
protected void after() {
try {
destoyLocalDatabase(dataSource);
} finally {
dataSource = null;
}
}
public void run(Callback callback) {
if (dataSource == null) {
throw new IllegalStateException("No DataSource");
}
Collection con = null;
try {
con = ds.getConnection(DB_USERNAME, PASSWORD);
callback.execute(con);
con.commit();
} finally {
if (con != null) con.close();
}
}
You can have this as a Rule in your base class:
public DatabaseTest {
#Rule
public LocalDatabase final localDatabase = new LocalDatabase();
}
And could could use it in a #Before method in any subclass
public UserDaoTest extends DatabaseTest {
#Before
public void populateInitialData() {
localDatabase.run(new Callback() {
#Override
public void execute(Connection con) {
...
}
});
}
...
}

Related

PowerMock: How to spy System.out.println?

Let's say I have the following class:
class MyClass {
public MyClass(){
}
public void hello() {
System.out.println("hello");
}
}
and I want to test 'hello' method:
#Test
public void testHello() {
MyClass mc = new MyClass();
mc.hello();
}
Now, I want to spy System.out.println and make sure that this method was called with "hello" as argument. How do I do it?
System.out is actually an instance of PrintStream, so my approach would be to create a mock of this class and direct output to that using the System.setOut method:
PrintStream outMock = Mockito.mock(PrintStream.class);
System.setOut(outMock);
System.out.println("Hello");
Mockito.verify(outMock).println("Hello");
Remember to restore the previous PrintStream instance after the test, preferably in a finally clause.

Unit test WCMUsePOJO class

I am writing unit test cases for following class which extends WCMUsePOJO. Now, this class is using a getSlingScriptHelper method shown below.
public class ConstantsServiceProvider extends WCMUsePojo {
private static final Logger logger = LoggerFactory.getLogger(ConstantsServiceProvider.class);
private String var1;
#Override
public void activate() throws Exception {
ConstantsService constantsService = getSlingScriptHelper().getService(ConstantsService.class);
if(constantsService != null) {
var1 = constantsService.getVar1();
}
}
public string getVar1() { return var1; }
}
The question is how do I mock getSlingScriptHelper method? Following is my unit test code.
public class ConstantsServiceProviderTest {
#Rule
public final SlingContext context = new SlingContext(ResourceResolverType.JCR_MOCK);
#Mock
public SlingScriptHelper scriptHelper;
public ConstantsServiceProviderTest() throws Exception {
}
#Before
public void setUp() throws Exception {
ConstantsService service = new ConstantsService();
scriptHelper = context.slingScriptHelper();
provider = new ConstantsServiceProvider();
provider.activate();
}
#Test
public void testGetvar1() throws Exception {
String testvar1 = "";
String var1 = provider.getVar1();
assertEquals(testvar1, var1);
}
}
The only thing that you should "have to"* mock is the SlingScriptHelper instance itself, so that it will mimic the dependency injection of the declared service.
Everything else (e.g. the Bindings instance) can be a concrete implementation, for example:
import org.apache.sling.api.scripting.SlingBindings;
import org.apache.sling.api.scripting.SlingScriptHelper;
import org.junit.Test;
import javax.script.Bindings;
import javax.script.SimpleBindings;
import static org.hamcrest.CoreMatchers.equalTo;
import static org.hamcrest.CoreMatchers.is;
import static org.hamcrest.MatcherAssert.assertThat;
import static org.mockito.Mockito.mock;
import static org.mockito.Mockito.when;
public class ConstantsServiceProviderTest {
private SlingScriptHelper mockSling = mock(SlingScriptHelper.class);
private ConstantsServiceProvider constantsServiceProvider = new ConstantsServiceProvider();
private Bindings bindings = new SimpleBindings();
#Test
public void testFoo() throws Exception {
//Arrange
final String expected = "Hello world";
final ConstantsService testConstantsService = new TestConstantsService(expected);
when(mockSling.getService(ConstantsService.class)).thenReturn(testConstantsService);
bindings.put(SlingBindings.SLING, mockSling);
//Act
constantsServiceProvider.init(bindings);
//Assert
final String actual = constantsServiceProvider.getVar1();
assertThat(actual, is(equalTo(expected)));
}
class TestConstantsService extends ConstantsService {
String var1 = "";
TestConstantsService(String var1) {
this.var1 = var1;
}
#Override
String getVar1() {
return var1;
}
}
}
The entry point here, as you said above, is via the init() method of the WCMUsePojo superclass (as this method is an implementation of the Use.class interface, this test structure also works for testing that via that interface, even if you don't use WCMUsePojo directly.)
*this could be any type of test-double, not necessarily a mock.
You shouldn't create a mock for ConstantsServiceProvider.class if you want to unit-test it. Instead, you should create mocks of its internal objects. So:
Create real instance of ConstantsServiceProvider with new
Mock objects that are returned by getSlingScriptHelper().getService(.) methods. Usually, dependencies are provided (injected) to classes by some container like Spring or simply provided by other classes of your app using setters. In both cases mocks creation is easy.
If your current implementation doesn't allow this - consider refactoring.
You are testing void activate() method which doesn't return anything. So, you should verify calling constantsService.getVar1() method.
I strongly advice you to study Vogella unit-testing tutorial
Here one of possible solution.
The main idea is to have a real object of your class but with overridden getSlingScriptHelper() to return mocked scriptHelper.
I mocked the ConstantsService as well but may be not needed, I don't know your code.
public class ConstantsServiceProviderTest {
#Mock
public SlingScriptHelper scriptHelper;
#Test
public void getVar1ReturnsActivatedValue() throws Exception {
// setup
final String expectedResult = "some value";
// Have a mocked ConstantsService, but if possible have a real instance.
final ConstantsService mockedConstantsService =
Mockito.mock(ConstantsService.class);
Mockito.when(
mockedConstantsService.getVar1())
.thenReturn(expectedResult);
Mockito.when(
scriptHelper.getService(ConstantsService.class))
.thenReturn(mockedConstantsService);
// Have a real instance of your class under testing but with overridden getSlingScriptHelper()
final ConstantsServiceProvider providerWithMockedHelper =
new ConstantsServiceProvider() {
#Override
SlingScriptHelper getSlingScriptHelper() {
return scriptHelper;
}
};
// when
String actualResult = providerWithMockedHelper.getVar1();
// then
assertEquals(expectedResult, actualResult);
}
}

How do I use Mockito to mock a protected method?

I’m using Mockito 1.9.5. How do I mock what is coming back from a protected method? I have this protected method …
protected JSONObject myMethod(final String param1, final String param2)
{
…
}
However, when I attempt to do this in JUnit:
final MyService mymock = Mockito.mock(MyService.class, Mockito.CALLS_REAL_METHODS);
final String pararm1 = “param1”;
Mockito.doReturn(myData).when(mymock).myMethod(param1, param2);
On the last line, I get a compilation error “The method ‘myMethod’ is not visible.” How do I use Mockito to mock protected methods? I’m open to upgrading my version if that’s the answer.
This is not an issue with Mockito, but with plain old java. From where you are calling the method, you don't have visibility. That is why it is a compile-time issue instead of a run-time issue.
A couple options:
declare your test in the same package as the mocked class
change the visibilty of the method if you can
create a local (inner) class that extends the mocked class, then mock this local class. Since the class would be local, you would have visibility to the method.
Responding to the request for a code sample of option 3 from John B's answer:
public class MyClass {
protected String protectedMethod() {
return "Can't touch this";
}
public String publicMethod() {
return protectedMethod();
}
}
#RunWith(MockitoJUnitRunner.class)
public class MyClassTest {
class MyClassMock extends MyClass {
#Override
public String protectedMethod() {
return "You can see me now!";
}
}
#Mock
MyClassMock myClass = mock(MyClassMock.class);
#Test
public void myClassPublicMethodTest() {
when(myClass.publicMethod()).thenCallRealMethod();
when(myClass.protectedMethod()).thenReturn("jk!");
}
}
You can use Spring's ReflectionTestUtils to use your class as it is and without needing of change it just for tests or wrap it in another class.
public class MyService {
protected JSONObject myProtectedMethod(final String param1, final String param2) {
return new JSONObject();
}
public JSONObject myPublicMethod(final String param1) {
return new JSONObject();
}
}
And then in Test
#RunWith(MockitoJUnitRunner.class)
public class MyServiceTest {
#Mock
private MyService myService;
#Before
public void setUp() {
MockitoAnnotations.initMocks(this);
when(myService.myPublicMethod(anyString())).thenReturn(mock(JSONObject.class));
when(ReflectionTestUtils.invokeMethod(myService, "myProtectedMethod", anyString(), anyString())).thenReturn(mock(JSONObject.class));
}
}
Something like following worked for me, using doReturn() and Junit5's ReflectionSupport.
[Note: I tested on Mockito 3.12.4]
ReflectionSupport.invokeMethod(
mymock.getClass()
// .getSuperclass() // Uncomment this, if the protected method defined in the parent class.
.getDeclaredMethod("myMethod", String.class, String.class),
doReturn(myData).when(mymock),
param1,
param2);
John B is right, this is because the method you're trying to test is protected, it's not a problem with Mockito.
Another option on top of the ones he has listed would be to use reflection to gain access to the method. This will allow you to avoid changing the method you are testing, and avoid changing the pattern you use to write tests, and where you store these tests. I've had to do this myself for some tests where I was not allowed to change the existing code base which included a large number of private methods that needed to be unit tested.
These links explain Reflection and how to use it very well, so I will link to them rather than copy:
What is reflection and whit is it useful
How to test a class that has private methods, fields, or inner classes
WhiteBox.invokeMethod() can be handy.
public class Test extend TargetClass{
#Override
protected Object method(...) {
return [ValueYouWant];
}
}
In Spring, you can set it high high-priority like this:
#TestConfiguration
public class Config {
#Profile({"..."})
#Bean("...")
#Primary // <------ high-priority
public TargetClass TargetClass(){
return new TargetClass() {
#Override
protected WPayResponse validate(...) {
return null;
}
};
}
}
It is the same to override the origin bean.

How to have individual SetUp functions in Junit

I have two test functions and for each I want to have different #Before methods. How to achieve this ?
Although it seems to be convenient to organize all the test under the same class, for your case I think the best option is to separate the tests into different classes, each one with his corresponding setUp.
An alternative (I prefer the previous option) could be call the setUp directly in your test method, like the example as follows:
public class FooTest {
public void setUpMethod1() {
// do setUp things
}
public void setUpMethod2() {
// do setUp things
}
#Test
public void testMethod1() {
setUpMethod1();
// Test
}
#Test
public void testMethod2() {
setUpMethod2();
// Test
}
}
Only as a curiosity (IMO not recomended for your case), you can override the default junit RunListener with your own implementation. Method testStarted is executed before every test and you have access to class and methodName to be able to identify the running test. Dummy sample:
public class MyRunListener extends RunListener {
#Override
public void testStarted(Description description) throws Exception {
//...
Class testClass = description.getClass();
String methodName = description.getMethodName();
//...
}
}
Hope it helps.

how do I use powermockito verifyNew?

Having trouble with this. I've used Powermockito quite a bit in the past. Normally this is pretty smooth. I figured I'd post my problem rather than continue to rummage through examples. So the goal is to verify a call to new for a class. I don't think this is the most popular feature of powermockito.
Here's the test:
import static org.powermock.api.mockito.PowerMockito.verifyNew;
import static org.powermock.api.mockito.PowerMockito.whenNew;
#RunWith(PowerMockRunner.class)
#PrepareForTest(ClassUnderTest.class)
public class VerifyNewTest {
ClassUnderTest myClassUnderTest = new ClassUnderTest();
#Before
public void setUp() throws Exception {
}
#Test
public void test() throws Exception {
whenNew(Collaborator.class).withNoArguments().thenReturn(new Collaborator());
myClassUnderTest.doSomething();
verifyNew(Collaborator.class).withNoArguments();
}
}
and said classes
public class ClassUnderTest {
public void doSomething() {
new Collaborator();
}
}
public class Collaborator {
}
My goal was to make this as simple as possible. I suppose I could have added some mock objects and stubbed some behavior. Anyway, I get.
org.mockito.exceptions.misusing.UnfinishedStubbingException: Unfinished stubbing detected here:
-> at org.powermock.api.mockito.internal.invocationcontrol. MockitoNewInvocationControl.expectSubstitutionLogic(MockitoNewInvocationControl.java:65)
E.g. thenReturn() may be missing.
Examples of correct stubbing:
when(mock.isOk()).thenReturn(true);
when(mock.isOk()).thenThrow(exception);
doThrow(exception).when(mock).someVoidMethod();
Hints:
1. missing thenReturn()
2. you are trying to stub a final method, you naughty developer!
Return a mock object in the whenNew() clause would work in your case.
#Test
public void test() throws Exception {
whenNew(Collaborator.class).withNoArguments().thenReturn(mock(Collaborator.class));
myClassUnderTest.doSomething();
verifyNew(Collaborator.class).withNoArguments();
}