How does cucumber initialize a given step definition Java class which corresponds to a given feature file having multiple scenarios and all scenarios are sharing a Background (Given condition) to initialize a instance variable.
My Question is to know is it like one step definition Java class 's object per scenario given in feature file?
If my understanding is correct , does that impact performance of execution? Can it be improved having thread safety intact.
Related
I am trying to run two step definition files(cucumber) simultaneously in that I applied #Before annotation in one step definition file. While i am running these, annotation is applying to both and giving the result. How can i stop or control annotation is applicable to only one step definition file?
All step definition files are parsed when Cucumber starts executing. Cucumber then uses the scenarios in your feature files to determine which step definitions to call. There is no concept of "running a step definition file".
A Before hook will run before each Scenario that Cucumber executes. It makes no difference which feature file the scenario is written in or which step definition file the hook is defined in.
You may want to consider using a Background instead, especially if a non-technical reader of the feature file would find the behaviours it describes important. A Background runs before each scenario written in the same feature file.
Alternatively, you might accomplish what you want by using conditional (or tagged) hooks. A conditional Before hook will only be run if the scenario has tags that satisfy the hook's tag expression.
I read there are 5 disciplines in a unified process, Requirements, Analysis, design, Implementation, and test.
I've basically done the following UML's and I'm trying to add an explanation of how I adhered to the unified process. I did the following UML's for my project: Use case, Analysis class, Design class, Activity, Sequence, Deployment, state machine, and component.
I can already tell based on content that the use case falls into the categories of requirements. Analysis class falls into the category of analysis. Design class in design. But what about the other 2 disciplines? I am having some trouble understanding unified process. But if I were to assign the UML's to a discipline, what would they be assigned to.
Implementation will be a mix of class and component and deployment diagrams. For test there's nothing in pure UML. You can create your own profile for it. Basically it ends up in sort of use case diagram for business with traces to requirements being marked in some way. Unit testing can trace classes to requirements. This is a wide open area where you can write more than one thesis about.
Are there any creational design patterns that allow for completely new objects (as in newly written) to be instantiated without having to add a new statement somewhere in existing code?
The main problem to solve is how to identify the class or classes to instantiate. I know of and have used three general patterns for discovering classes, which I'll call registration, self-registration and discovery by type. I'm not aware of them having been written up in a formal pattern description.
Registration: Each class that wants to be discovered is registered somewhere where a framework can find it:
the class name is put in an environment variable or Java system property, in a file, etc.
some code adds the class or its name to a singleton list early in program execution
Self-registration: Each class that wants to be discovered registers itself, probably in a singleton list. The trick is how the class knows when to do that.
The class might have to be explicitly referred to by some code early in the program (e.g. the old way of choosing a JDBC driver).
In Ruby, the code that defines a class can register the class somewhere (or do anything else) when the class is defined. It suffices to require the file that contains the class.
Discovery by type: Each class that wants to be discovered extends or implements a type defined by the framework, or is named in a particular way. Spring autowiring class annotations are another version of this pattern.
There are several ways to find classes that descend from a given type in Java (here's one SO question, here's another) and Ruby. As with self-registration, in languages like those where classes are dynamically loaded, something has to be done to be sure the class is loaded before asking the runtime what classes are available.
One things which I think here is that someone needs to do a new to your newly written Class. If you are not doing that then may be some framework needs to do that.
I could remember something similar which I did in one of my side projects using Java Spring . I had an interface and multiple implementations to it. My project required to iterate over all the implementations do some processing. Now for this even I was looking for some solution with which I would not have to manually do the instantiation of that particular class or some explicit wiring of that particular class. So Spring facilitated me to do that through #Autowired annotation. It injected all the implementation of that interface on the fly. Eg :-
#Autowired
private List<IMyClass> myClassImplementations;
Now in the above example I can simply iterate over the list of implementations injected and I would not have to do instantiation of my new implementation every time I write a new one.
But I think in most of the cases it would be difficult to use this approach (even though it fits in my case). I would rather go with a Factory pattern in general case and try to use that for creating new instances. I know that would require new but in my perception engineering it in a way that its object is automatically created and injected is a bit an extra overhead.
Considering the following class diagram:
The class System is active and its behaviour is to continuously
call filter on PressureSensorFilter passing
PressureSensor.Pressure as argument
call Display.show passing the output param of
PressureSensorFilter.filter as argument
I would like to model the behaviour of System through an ActivityDiagram.
The main challenge in doing this is accessing the property PressureSensor of System.
After reading the UML 2.5 specification, I believe that the only way to do this is to use ReadSelfAction(pag 457 UML 2.5 spec) and ReadStructuralFeatureAction (pag 466 UML 2.5 spec) as depicted by the following Activity diagram:
where
ReadSelfAction gives as output a current Instance of System.
ReadPressureSensorFe.. is a REadStructuralFeatureAction that reads the property PressureSensor of the object give at its input pin which in this case is the current Instance of System.
CallBesselFilter.filter Action and CallDisplay.show Action are two CallOperationAction(s) that call PressureSensorFilter.filter and Display.show respectively.
The issue with this is that is very convoluted and unclear.
Is there any less convoluted and more clear way to describe the behaviour of System through an Activity diagram?
The ReadSelfAction as extra action is superfluous. You can reduce the control flow like this:
The pressure is read by the filter from the Pressure class' property. The filtered output is sent to Display and looping....
You should look into SysML. It's designed to cope with exactly that kind of problems you deal with.
It all depends on what detail you would like to provide in your activity diagram. The diagram you provide is correct. By the way, its level of details could be directly used to generate code. If you would like to describe behavior more abstract, do not use actions like read structural feature etc. But in your example, it is very good and precised way of description.
According to the UML spec we can denote a dependency between two classes by means of <<Create>> or <<Instantiate>> stereotypes.
Do you know what is the differences between those stereotypes?
It is written in UML spec 2.5 (chap. 22.3 Standard Stereotypes):
For <<Create>>
A usage dependency denoting that the client classifier creates
instances of the supplier classifier
For <<Instantiate>>
A usage dependency among classifiers indicating that operations on the
client create instances of the supplier
Michael Jesse Chonoles
Yes, «create» is used on sequence diagrams. It's a stereotype on a message. «Create» is also a stereotype on a behavioral feature in a classifier indicating that is a constructor of instances of that classifier (or the equivalent for non-object-oriented items).
When «Create» is used on a dependency, it doesn't seem much different than «Instantiate». Personally, I use the dependency «Instantiate».when I mean a true object-oriented instantiation arrived at by calling the constructor (which is how the I would translate the model into code). I would use «Create» when it's a different kind of creation, either more indirect, conceptual, or non-object-oriented features.
Here are some examples. I would use «Create» to say MSWord-->«Create» a Document, a modeler «Create» a model. Though I normally wouldn't model this in detail, I would use «Create» to indicate a component «Create» a new database record, the database manager «Create» a new database, a programmer «Create» a new app. Or create a new element in a (non-oo) array. These can happen without directly calling a traditional object-oriented constructor -- and can't be directly converted to code.
On the other hand, if I had a marriage operation on a person, it would probably «Instantiate» the association class object of marriage.
Because most of my modeling is conceptual, in practise, I tend to use «create». Though, even then it doesn't come up that often.
I noticed that << Create >> stereotype can also be applied not only to "Usage" dependency but also to
"BehavioralFeature" (see section 22.2 in UML spec).
In UML "BehavioralFeature" corresponds to particular methods in a class or interface.
Hence if we mark particular method in a class with << Create >> or << Destroy >>
we mean that it creates/destroys an instances of this class.
We can make a parallel between marking a method with << Create >>
and marking a Usage Dependency with << Create >>.
If we mark a Usage Dependency with << Create >> then
this means that particular method in a Client Class creates an instance of a Supplier Class.
Hence we create an instance of Supplier in the body of our client class.
Client and Supplier are strongly coupled here.
On the other hand if we mark a Usage Dependency with << Instantiate >> then
Client class delegates the creation of Supplier to the other Objects.
Hence, he creates Supplier indirectly.
In this case Client and Supplier are loosly coupled.
For example, this happens if we create Supplier via one of the Creational Patterns: Object Pool, Prototype, Factory Method etc.
Note:
By and large, it is not very clear the differences from the spec.
Hope in future releases of it (more than 2.5 version) we have more clear definitions.
The person who instructs me on SyML/UML has done MSBE in SyML/UML for very many years in large very companies.
I asked him how to draw a diagram that shows:
The 'system Boot process' loads (from ROM) and runs the 'system MAIN process/application'.
He said I should use the «Create» usage dependency.
So as I see it:
You use «Create» to show that one process runs 'big' things - like
booting up an entire external process / SW item / application.
You use «Instantiate» to show that within a given process, a code
segment instantiates "creates" an object instance from a class
definition.