User guide contains following:
Usually, an extension is instantiated only once.
It's not very clear when extension can be instantiated many times? I'm supporting test suite with multiple extensions and every extension stores it's state in class fields. Everything works fine, but can I rely on this or should I refactor this code to use ExtensionContext.Store?
Usually, an extension is instantiated only once. So the question becomes relevant: How do you keep the state from one invocation of an extension to the next?
I think this sentence shall highlight that the same instance of an extension might be re-used for multiple tests. I doubt that the instance might be replaced in the middle of a test.
Multiple instances of an extension might be instantiated when a test uses programmatic extension registration (with #RegisterExtension). In such case, the test class creates its own instance of the extension. JUnit cannot reuse this instance in other test classes. But an instance created by declarative extension registration (with #ExtendWith) might be used for multiple test classes.
Related
I'm using DynamicNode very successfully in a framework that dynamically generates tests and executes them.
Now I have a need to execute some code after all DynamicNode collections have executed. This can mean that I have a single JUnit5 class with multiple methods that return Iterable<DynamicNode>, but I want to run something only after all the test methods have completed.
Is there a way to do this automatically ?
EDIT: ideally I would like my framework to inject the code to be executed automatically, without the user needing to add a #AfterAll annotation on a method and write some extra code.
Each method that is annotated with #TestFactory takes part in the default lifecycle. That means in your case an #AfterAll annotated method should do the trick.
#AfterAll
Denotes that the annotated method should be executed after all
#Test, #RepeatedTest, #ParameterizedTest, and #TestFactory
methods in the current class; analogous to JUnit 4’s #AfterClass.
Such methods are inherited (unless they are hidden or overridden) and
must be static (unless the "per-class" test instance lifecycle is
used).
Copied from https://junit.org/junit5/docs/current/user-guide/#writing-tests-annotations
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 am writing Objective-C unit tests in Xcode. I would like to extend my base class so I can reuse my setUp/tearDown methods. I created a header and put the imports there, since Xcode defaults to making just an implementation file.
Extending the base class works fine, except that all of its test methods are run a second time (or n times, depending on number of children).
My question is if this is the appropriate practice, or should I try something like base classes with no test methods?
I'm building a couple of customs FxCop rules and one of the rules needs to enforce that a constructor is called in specific methods. For that, I need to create a list of callers, to that specific constructor, prior to performing the actual test. How is this possible? Is there some kind of handle to acquire a list of all loaded assemblies in the ApplicationDomain, where I can iterate through the classes and find the constructor Method object? Ideally the list of callers should be composed in the BeforeAnalysis method.
The Microsoft.FxCop.Sdk.CallGraph.CallersFor(Method) method may give you what you want. However, the general approach you seem to be describing is rarely a good idea because it would typically assign the problems to the wrong target. For example, in the scenario you describe, it would presumably be desirable to attribute the problems to the methods that should but do not contain the target contructor call. However, if your analysis target is the constructor, the detected problems will be attributed to the constructor rather than the methods that should have called it.
I think I haven't explained the question very well, but I see your point.
I have 3 different assemblies and for certain method calls from one assembly to another, I need to ensure that a benchmark constructor invoked. The benchmark class resides in a 4th assembly. Now my problem was that only VS2010 only loads one target assembly for analysis and when I used the CallGraph to construct the a list of methods calling the constructur, it would not find any. When Invoking FxCopCmd.exe manually I could just add the dependent assemblies manually with the /file: parameter.
My solution is to load the different assemblies manually (not relying on the loaded assembly in RuleUtilities.AnalysisAssemblies and contruct the list of callers in the BeforeAnalysis method.
RuleUtilities.GetAssembly(
RuleUtilities.AnalysisAssemblies
.First().Directory + "\\" + additionalAssemblyFilename)
.Types.SelectMany(type => type.Members)
.Where(member => member.IsPublic)
.Where(CanBeCastedToMethod)
.Cast<Method>()
.SelectMany(CallGraph.CallersFor);
With this approach I can contruct a list of callers, for each of the assemblies and for the benchmark class constructor. Works perfectly i VS2010.
We use RhinoMocks. I have a type into whose constructor 9 types are injected. I'd like a way of automocking the type, but being able to detect a particular method invocation on one of the injected objects (i.e. I only care about a single method invocation on one of the injected objects).
Is this possible, or do I have to manually inject all the mock objects into the constructor?
I haven't seen any frameworks that would auto-create these mocks for you. You can do it in your [SetUp] method, so at least the tests will not be cluttered with boilerplate code.
I need to check out http://autofixture.codeplex.com/. Its not really container specific, there is an extension for rhino mocks. Disclaimer: I haven't tried autofixture yet.