I would like to write a JUnit5 Extension where I have to take some action when a test method annotated with #Disabled is found. Unfortunately, beforeTestExecution() is not called for such methods. Does anybody have an idea how to intercept such #Disabled test methods ?
Thanks !
As described in the User Guide, you can disable the built-in ExecutionCondition that handles #Disabled by default by setting junit.jupiter.conditions.deactivate to org.junit.*DisabledCondition (see Configuration Parameters on how to set it). This will cause your tests to be executed.
Next, you need to implement your own ExecutionCondition extension, check for #Disabled, take your action and return ConditionEvaluationResult.disabled("...").
In order to avoid having to register your extension on each test class, you can activate Automatic Extension Registration and register your extension globally.
Depending on what you want to achieve, it may be easier to register your own TestExecutionListener (see Plugging in Your Own Test Execution Listeners) and implement executionSkipped().
The extension point used here is https://github.com/junit-team/junit5/blob/master/junit-jupiter-api/src/main/java/org/junit/jupiter/api/extension/ExecutionCondition.java
It might be interesting to find out how several implementors compose, i.e. if the 2nd one will be called at all and under what circumstances. You’ll probably have to dive into Jupiter code or do some experiments.
Related
Is it a good practice to write a EXPECT(something) inside a test double (e.g. spy or mock) method? To ensure the test double is used in a specific way for testing?
If not, what would be a preferred solution?
If you would write a true Mock (as per definition from xUnit Test Patterns) this is exactly what defines this kind of test double. It is set up with the expectations how it will be called and therefore also includes the assertions. That's also how mocking frameworks produce mock objects under the hood. See also the definition from xUnit Test Patterns:
How do we implement Behavior Verification for indirect outputs of the SUT?
How can we verify logic independently when it depends on indirect inputs from other software components?
Replace an object the system under test (SUT) depends on with a test-specific object that verifies it is being used correctly by the SUT.
Here, indirect outputs means that you don't want to verify that the method under test returns some value but that there is something happening inside the method being tested that is behaviour relevant to callers of the method. For instance, that while executing some method the correct behaviour lead to an expected important action. Like sending an email or sending a message somewhere. The mock would be the doubled dependency that also verifies itself that this really happened, i.e. that the method under test really called the method of the dependency with the expected parameter(s).
A spy on the other hand shall just record things of interest that happened to the doubled dependency. Interrogating the spy about what happened (and sometimes also how often) and then judging if that was correct by asserting on the expected events is the responsibility of the test itself. So a mock is always also a spy with the addition of the assertion (expectation) logic. See also Uncle Bobs blog The Little Mocker for a great explanation of the different types of test doubles.
TL;DR
Yes, the mock includes the expectations (assertion) itself, the spy just records what happened and lets the test itself asks the spy and asserts on the expected events.
Mocking frameworks also implement mocks like explained above as they all follow the specified xunit framework.
mock.Verify(p => p.Send(It.IsAny<string>()));
If you look at the above Moq example (C#), you see that the mock object itself is configured to in the end perform the expected verification. The framework makes sure that the mock's verification methods are executed. A hand-written would be setup and than you would call the verification method on the mock object yourself.
Generally, you want to put all EXPECT statements inside individual tests to make your code readable.
If you want to enforce certain things on your test stub/spy, it is probably better to use exceptions or static asserts because your test is usually using them as a black box, and it uses them in an unintended way, your code will either not get compiled, or it will throw and give you the full stack trace which also will cause your test to fail (so you can catch the misuse).
For mocks, however, you have full control over the use and you can be very specific about how they are called and used inside each test. For example in Google test, using GMock matchers, you can say something like:
EXPECT_CALL(turtle, Forward(Ge(100)));
which means expect Forward to be called on the mock object turtle with a parameter equal or greater than 100. Any other value will cause the test to fail.
See this video for more examples on GMock matchers.
It is also very common to check general things in a test fixture (e.g. in Setup or TearDown). For example, this sample from google test enforces each test to finish in a certain amount of time, and the EXPECT statement is in teardown rather than each individual test.
I found, that when I writing unit tests, especially for methods who do not return the value, I mostly write tests in white box testing manner. I could use reflection to read private data to check is it in the proper state after method execution, etc...
this approach has a lot of limitation, most important of which is
You need to change your tests if you rework method, even is API stay
the same
It's wrong from information hiding (encapsulation) point of view -
tests is a good documentation for our code, so person who will read
it could get some unnecessary info about implementation
But, if method do not return a value and operate with private data, so it's start's very hard (almost impossible) to test like with a black-box testing paradigm.
So, any ideas for a good solution in that problem?
White box testing means that you necessarily have to pull some of the wiring out on the table to hook up your instruments. Stuff I've found helpful:
1) One monolithic sequence of code, that I inherited and didn't want to rewrite, I was able to instrument by putting a state class variable into, and then setting the state as each step passed. Then I tested with different data and matched up the expected state with the actual state.
2) Create mocks for any method calls of your method under test. Check to see that the mock was called as expected.
3) Make needed properties into protected instead of private, and create a sub-class that I actually tested. The sub-class allowed me to inspect the state.
I could use reflection to read private data to check is it in the proper state after method execution
This can really be a great problem for maintenance of your test suite
in .Net instead you could use internal access modifier, so you could use the InternalsVisibleToAttribute in your class library to make your internal types visible to your unit test project.
The internal keyword is an access modifier for types and type members. Internal types or members are accessible only within files in the same assembly
This will not resolve every testing difficulty, but can help
Reference
I have an SWT project, where are several custom GUI elements, and i try to find a way, to build some kind of proxy on top of them, like the default ones built on top of Labels, Texts, etc. Is there a way to do this? It would be really convenient, to create a custom GuiTestObject subclass, and use it (make RFT use it?) to identify these custom GUI elements, like KTable for example, because now these controls are handled by the best class known by RFT, like Composite or ScrolledComposite, so it's impossible to expose the custom properties of these classes for testing, and the best way to test these elements is by image comparison.
If this is not possible, then is there a way, to somehow get a reference to the actual ui component from a GuiTestObject? I tried in debug mode, but it looks like, that the reference is intentionally hidden somehow. Is there a way, to bypass this, and somehow access the reference? (I couldn't see the actual ui element neither using the debugger, nor using reflection).
Any help is greatly appreciated!
The TestObject that you have available in the script should represent the actual object in the AUT.
As you said the methods exposed to the script would be limited to what is provided by the TestObject however RFT has API called "invoke" that you can use to invoke some method directly on the control.
You should find more info on invoke here: Using Invoke in RFT
Second , you should be able to extend an Existing proxy using the Proxy SDK of RFT where you can add custom behavior for the proxies
You can get more info aobut proxy SDK here:
Proxy SDK in RFT
I am working with testNG where I run an external test framework, receive the result data and assert it. To run the external test framework I need to set up a specification for which tests that should be run. To generate this specification I need to know which tests that are selected in the testNG .xml file.
The only way I could think of doing this is to parse the file manually. But I am hoping for a better solution than this.
Thanks for any answers!
//Flipbed
Edit:
My colleague found solutions to the problem.
In #Factory and #DataProvider annotated methods it is possible to add a parameter of the type ITestContext. Using the variable of that type, one can use the method .getAllTestMethods().
Create a new class that implements IMethodInterceptor. In this class one can override the method 'intercept'. The method takes a parameter of the type List which is a list of all methods that will be run by testNG.
If someone has any other suggestions feel free to add.
//Flipbed
The solution that we used was to number 2 in my edit. We implemented the IMethodInterceptor and used the methods list as well as the ITestContext to both view what tests will run and modify that list.
I am working on a VB.NET project which requires the extensive used of Unit Tests but am having problems mocking on of the classes.
Here is a breakdown of the issue:
Using NUnit and Rhino Mock 3.6
VS2010 & VB.NET
I have an interface which contains a number of methods and an Event.
The class which implements that Interface raises the event when one of the methods is called.
When I mock the object in my tests I can stub methods and create/assert expectations on the methods with no problems.
How do I configure the mock object so that when a method is called the event is raised so that I can assert that is was raised?
I have found numerous posts using C# which suggest code like this
mockObject.MyEvent += null...
When I try this 'MyEvent' does not appear in Intellisense.
I'm obviously not configuring my test/mock correctly but with so few VB.NET examples out there I'm drawing a blank.
Sorry for my lack of VB syntax; I'm a C# guy. Also, I think you should be congratulated for writing tests at all, regardless of test first or test last.
I think your code needs refactoring. It sounds like you have an interface that requires implementations to contain an event, and then another class (which you're testing) depends on this interface. The code under test then executes the event when certain things happen.
The question in my mind is, "Why is it a publically exposed event?" Why not just a method that implementations can define? I suppose the event could have multiple delegates being added to it dynamically somewhere, but if that's something you really need, then the implementation should figure out how that works. You could replace the event with a pair of methods: HandleEvent([event parameters]) and AddEventListener(TheDelegateType listener). I think the meaning and usage of those should be obvious enough. If the implementation wants to use events internally, it can, but I feel like that's an implementation detail that users of the interface should not care about. All they should care about is adding their listener and that all the listeners get called. Then you can just assert that HandleEvent or AddEventListener were called. This is probably the simplest way to make this more testable.
If you really need to keep the event, then see here for information on mocking delegates. My advice would be to mock a delegate, add it to the event during set up, and then assert it was called. This might also be useful if you need to test that things are added to the event.
Also, I wouldn't rely on Intellisense too much. Mocking is done via some crafty IL code, I believe. I wouldn't count on Intellisense to keep up with members of its objects, especially when you start getting beyond normal methods.