Can I run a custom rule only for a particular test method in a test class?
public class TestClassExample
{
#Rule
public CustomRuleForOneEqualsOne customRuleForOneEqualsOne = new CustomRuleForOneEqualsOne();
#Test
public void test_OneEqualsOne()
{
assertEquals(1, 1);
}
#Test
public void test_TwoEqualsTwo()
{
assertEquals(2, 2);
}
}
In the above test class can I use my customRuleForOneEqualsOne rule be used only for test method test_OneEqualsOne and not for test_TwoEqualsTwo.
I've seen other solutions on Stack Overflow:
Move the two test methods into different class [say this option is not possible for particulr scenario] (or)
JUnit: #Before only for some test methods? as described by this post
I can somehow use the test method name and skip over the execution of the rule
but a drawback of this approach would be, each time I use the rule in a specific class for a specific set of methods, I need to add all those method names to a list to see if they are found, to determine the execution of the rest of the logic.
Is there any way to use a custom rule in a test class for a particular set of test methods while ignoring them for the other test methods in the same test class?
For the best of my knowledge, #Rule applies to all tests. Therefore, if you need #Rule to be used in a single #Test method only, don't use #Rule. In that case, your code would look like this:
public class TestClassExample {
#Test
public void test_OneEqualsOne() {
CustomRuleForOneEqualsOne customRuleForOneEqualsOne = new CustomRuleForOneEqualsOne();
// use customRuleForOneEqualsOne
}
#Test
public void test_TwoEqualsTwo() {
assertEquals(2, 2);
}
}
Related
I have a class under test whose constructer looks like this :
public class ClassUnderTest {
ClientOne clientOne;
ClientTwo clientTwo;
OtherDependency otherDependency;
#Inject
public ClassUnderTest(MyCheckedProvider<ClientOne> myCheckedProviderOne,
MyCheckedProvider<ClientTwo> myCheckedProviderTwo,
OtherDependency otherDependency) throws Exception {
this.clientOne = myCheckedProviderOne.get();
this.clientTwo = myCheckedProviderTwo.get();
this.otherDependency = otherDependency;
}
.
.
.
}
And the CheckedProvider looks thus :
public interface MyCheckedProvider<T> extends CheckedProvider<T> {
#Override
T get() throws Exception;
}
I could mock the clients, but how do I initialise the providers with my mocked clients.I use a combination of junit and mockito for writing tests.Any inputs would be appreciated.
What you could do is to mock providers rather than clients. ClientOne and ClientTwo are the types you are passing into your generic class, they are not variables and hence not something you want to mock. In contrast, the providers you are passing to the constructor are really variables, and what you need to control (simulate) are the behaviors of these variables.
public class ClassTest {
private static final CientOne CLIENT_ONE = new ClientOne();
private static final ClientTwo CLIENT_TWO = new ClientTwo();
#Mock
private MyCheckedProvider<ClientOne> providerOne;
#Mock
private MycheckedProvider<ClientTwo> providerTwo;
private ClassUnderTest classUnderTest;
#Before
public void setUp() {
when(providerOne.get()).thenReturn(CLIENT_ONE);
when(providerTwo.get()).thenReturn(CLIENT_TWO);
classUnderTest = new ClassUnderTest(providerOne, providerTwo, otherDependency);
}
}
As the other answer suggests, you could easily mock the providers, too.
But youMyCheckedProvider don't have to.
You already have an interface sitting there, so what would prevent you from creating something like
class MyCheckedProviderImpl<T> implements MyCheckedProvider<T> {
and that think takes a T object in its constructor and returns exactly that?
That is more or less the same what the mocking framework would be doing.
This question is more like open discussion. I would like to start with an example. Suppose there is one service FooService
public interface IFooService { void Method1(){}}
public class FooService: IFooService { void Method1(){ ... }}
In order to test the service , we write the unit test code like below, no external services
public void TestMethod1(){ ... }
Then suppose in Method1 we need to use another class called AService which inherit from IAService
public interface IAService {void AMethod1(){}}
public class AService : IAService { void AMethod1() {}}
public class FooService : IFooService {
private IAService a;
public FooService (IAService a){ this.a = a;}
void Method1(){ a.AMethod1(); ..... business logic ..... }
}
Then we have to refactor the unit test to mock AService
public void TestMethod1(){
IMockAService aService = MockRepository.StrickMock<IAService>();
.....
}
So when need more external services, we have to add mock service, if some of services changed the logic or add or remove parameters, and so on. If there are 100 test cases, we have to modify all of test cases.
So what's the best solution for mocking increasing external services and effective way to handle any changes of external dependencies for example : add/remove parameters of methods.
thanks
Most times for me it's enough to create the class under test in a Setup method, leaving you with only one place to adapt when the constructor signature changes.
Alternatively you can move construction of the class under test to a private method.
Same goes for methods. Often you can wrap the call to a method under test in a private method. This is especially helpful, if you don't have to set up all passed parameters in every test, but can use defaults, which you might have prepared in your Setup method.
I am using PowerMockito and jUnit to write unit test cases.
public class Foo {
private String resolveApplicationId() {
return "testApplication";
}
}
Here is my test case
#RunWith(PowerMockRunner.class)
#PrepareForTest(Foo.class)
public class test{
#Before
public void prepareTest() {
foo = PowerMockito.spy(new Foo());
}
#Test
public void checkApplicationIdIsResolved() throws Exception {
PowerMockito.doNothing().when(foo, "myPrivateMethod");
PowerMockito.verifyPrivate(foo).invoke("myPrivateMethod");
//Assert Here the returned value
}
}
Please tell me
1. how can I assert the value returned by the method when it is called
2. how can I call the private method
3. if not then what actually I verify when I write test case for private methods.
Thanks.
Testing private method does not differ from testing public method. If there is no external dependencies you even don't need to create and use any mocks. The only problem is with invocation of the private method from test. This is described here or you may use spring utils.
So you don't need to mock the method you are testing. You only require to mock other objects which are not tested in this particular test. So you test would look like
#Test
public void checkApplicationIdIsResolved() throws Exception {
// makeResolveIdAccessible();
// if needed setup mocks for objects used in resolveApplicationId
assertEquals(expectedApplicationId, foo.resolveApplicationId())
}
Consider the following sample code:
#Stateless
public class MyBean {
private SomeHelper helper;
private long someField;
#PostConstruct
void init() {
helper = new SomeHelper();
someField = initSomeField();
}
long initSomeField() {
// perform initialization
}
public void methodToTest() {
helper.someMethod();
long tmp = 3 + someField;
}
}
And here is the test template, that I always use
public class MyBeanTest {
#Spy
#InjectMocks
private MyBean testSubject;
#Mock
private SomeHelper mockedHelper;
#Before
public void before() {
MockitoAnnotations.initMocks(this);
doReturn(1L).when(testSubject).initSomeField();
}
#Test
public void test() {
testSubject.methodToTest();
// assertions
}
}
The problem with testing methodToTest is that it needs field someField to be initialized. But the initialization is done in #PostConstruct method. And I can't run this method before call to testSubject.methodToTest(), because it will re-initialize helper. Also, I don't want to manually set up all the mocks. And I don't want to use reflection to set the someField, because that would make MyBeanTest vulnerable to MyBean refactoring. Can anybody propose, maybe better design to avoid situations like this?
A few notes:
Logic in initSomeField could be quite heavy (including calls to database), so I want to initialize it only once in a #PostConstruct method.
I don't want to create a setter for this field or widen its access modifier, because that would allow unwanted changes to my field.
If your test is in the same package as your class, then you can just call initSomeField directly, since it's package private. You can either do this in each individual test method, or in your #Before method, provided it runs after initMocks.
I am using PowerMock to mock static methods in junit tests, typically done as follows:
#RunWith(PowerMockRunner.class)
#PrepareForTest({Foo.class,Bar.class})
public class SomeUnitTest {
#Before
public void setUpTest() {
setUpFoo();
setUpBar();
}
private void setUpFoo() {
mockStatic(Foo.class);
when(Foo.someStaticMethod()).thenReturn(1);
}
private void setUpBar() {
mockStatic(Bar.class);
when(Bar.someStaticMethod()).thenReturn(2);
}
#Test
public void someTestCase() {
...
}
}
This works fine, but I'm finding that specifying the #PrepareForTest annotation is preventing me from making my testing API flexible.
What I'd like to do is something like the following:
public class MockLibraryOne {
public static void setUpLibraryOne() {
setUpFoo();
setUpBar();
}
private static void setUpFoo() {
mockStatic(Foo.class);
when(Foo.someStaticMethod()).thenReturn(1);
}
private static void setUpBar() {
mockStatic(Bar.class);
when(Bar.someStaticMethod()).thenReturn(2);
}
}
#RunWith(PowerMockRunner.class)
public class SomeUnitTest {
#Before
public void setUpTest() {
MockLibraryOne.setUpLibraryOne();
}
#Test
public void someTestCase() {
...
}
}
Here my unit test has a dependency on LibraryOne, but it does not know which classes LibraryOne depends on, so it does not know which classes to add to the #PrepareForTest annotation.
I could make SomeUnitTest extend MockLibraryOne and add the #PrepareForTest annotation to the MockLibraryOne class, but I will have dependencies on more than just MockLibraryOne in other unit tests, so inheritance is not a general solution.
Is there some way of programmatically preparing a class for testing under PowerMock, instead of using the #PrepareForTest annotation? For example, something like the following:
public class MockLibraryOne {
public static void setUpLibraryOne() {
setUpFoo();
setUpBar();
}
private static void setUpFoo() {
prepareForTest(Foo.class);
mockStatic(Foo.class);
when(Foo.someStaticMethod()).thenReturn(1);
}
private static void setUpBar() {
prepareForTest(Bar.class);
mockStatic(Bar.class);
when(Bar.someStaticMethod()).thenReturn(2);
}
}
I guess it would be nice if PowerMockRunner processed the #PrepareForTest annotation a little differently: for each specified class, it should not only add that class (and its hierarchy) to the list of classes to prepare for mocking, but then examine that class to see if it has any #PrepareForTest annotations as well:
#RunWith(PowerMockRunner.class)
#PrepareForTest({MockLibraryOne.class})
public class SomeUnitTest {
...
}
#PrepareForTest({Foo.class,Bar.class})
public class MockLibraryOne {
...
}
}
So in this the #PrepareForTest annotation on SomeUnitTest would find MockLibraryOne, and the #PrepareForTest annotation there would drag in Foo.class and Bar.class as well.
So perhaps writing my own test runner to replace PowerMockRunner may be a solution.
Or perhaps there's a simpler solution, using PowerMockAgent class, for example?
edit: Mock Policies may be one solution: https://code.google.com/p/powermock/wiki/MockPolicies
edit: Mock Policies works with PowerMockRunner but not (it seems) with PowerMockRule (which I sometimes require due to class loader issues).
What you try to achieve will not work.
The problem is that powermock must rewrite the client class's code to intercept the static invocation and it can't do this after the class is loaded. Thus it can only prepare a class for test before it is loaded.
Let's assume you want to mock the System.currentTimeMillis invocation in the following simple class.
class SystemClock {
public long getTime() {
return System.currentTimeMillis();
}
}
Powermock will not change the code of java.lang.System.currentTimeMillis, because it can't. Instead it changes the SystemClock's byte code so that it does not invoke System.currentTimeMillis anymore. Instead it invokes some other object that belong to powermock.
This is how powermock get's full control over the return value and allows you to write a test like this:
#RunWith(PowerMockRunner.class)
#PrepareForTest({ SystemClock.class })
public class PowerMockitoTest {
#Test
public void systemTimeMillis() {
SystemClock systemClock = new SystemClock();
PowerMockito.mockStatic(System.class);
PowerMockito.when(System.currentTimeMillis()).thenReturn(12345L);
long time = systemClock.getTime();
assertEquals(12345L, time);
}
}
You can see that powermock has rewritten the client class in the stacktrace of your debugger. Set a breakpoint at SystemClock.getTime and step into the invoked method.
As you can see SystemClock invokes a MockGateway.
If you take a look at the variables on the stack of the MockGateway invocation, you can see how the original System.currentTimeMillis method is handled.
Perhaps you're looking for a mock policy?
Could you help this (taken from documentation)?
You can also prepare whole packages for test by using wildcards:
#PrepareForTest(fullyQualifiedNames="com.mypackage.*")
So you can add the whole library to your prepare...
Why do you even want to mock static methods? Why not wrap those static methods in a class that you can mock with mockito?
class FooWraper {
void someMethod() {
Foo.someStaticMethod()
}
}
and then you can create a mock of your FooWraper. No need to use Powermock at all...