Open Generics Registration - dryioc

Suppose I have the following classes:
public class Setup { }
public class Configuration<T> where T : class
{
internal Configuration(Setup setup) { }
}
public class Process<T> where T : class
{
internal Process(Configuration<T> configuration) { }
}
I want to register these classes in DryIoc and need each Process<T> to be singleton (as would be Configuration<T>). So, Process<ClassA> would resolve the same instance, and Process<ClassB> will do the same. But Process<ClassA> and Process<ClassB> would be 2 different instances.The same applies to Configuration<T>.How would I register these 3 classes to achieve what I need?Note that constructors are internal.
This is what I've done without success:
var container = new Container();
container.Register<Setup>(Reuse.Singleton);
container.Register(typeof (Configuration<>),
made: Made.Of(typeof (Configuration<>).GetConstructorOrNull(true, typeof (Setup))));
container.Register(typeof(Process<>), Reuse.Singleton,
Made.Of(typeof(Process<>).GetConstructorOrNull(true, typeof(Configuration<>))));
I get: "An exception of type 'System.NullReferenceException' occurred in DryIoc.dll but was not handled in user code" when, as an example I dovar a = container.Resolve<Process<EventArgs>>();

The problem is with getting constructor from generic type. For now you may use DryIoc API to get ConstructorWithResolvableArgumentsIncludingNonPublic:
Working sample looks like that:
var container = new Container();
container.Register<Setup>(Reuse.Singleton);
container.Register(typeof(Configuration<>), Reuse.Singleton,
made: FactoryMethod.ConstructorWithResolvableArgumentsIncludingNonPublic);
container.Register(typeof(Process<>), Reuse.Singleton,
FactoryMethod.ConstructorWithResolvableArgumentsIncludingNonPublic);
var p = container.Resolve<Process<EventArgs>>();
In future versions it will be more simple like FactoryMethod.Constructor(includeNonPublic: true).
Update with workaround:
This is an actual issue in DryIoc 2.9.7 with creating singletons with internal constructor. The fix is on the way. For now you can use a workaround by disabling certain singleton optimizations with rule:
var container = new Container(rules => rules.WithoutEagerCachingSingletonForFasterAccess());
Updated live sample.
Update with fix:
The problem is fixed in DryIoc 2.10

Related

How to unit test private methods in Typescript

When I tried to do unit testing for private methods in a Class getting error as private methods are only accessible inside the class. Here I added sample snippet for my class and mocha test. Kindly provide me solution to implement unit test for private methods.
Class Name: Notification.ts
class Notification {
constructor() {}
public validateTempalte() {
return true;
}
private replacePlaceholder() {
return true;
}
}
Unit Test:
import {Notification} from 'Notification';
import * as chai from "chai";
describe("Notification", function(){
describe('#validateTempalte - Validate template', function() {
it('it should return success', function() {
const result = new Notification()
chai.expect(result.validateTempalte()).to.be.equal(true);
});
});
describe('#replacePlaceholder - Replace Placeholder', function() {
it('it should return success', function() {
const result = new Notification()
// As expected getting error "Private is only accessible within class"
chai.expect(result.replacePlaceholder()).to.be.equal(true);
});
});
});
As a workaround, currently, I am changing access specifier of function replacePlaceholder to public. But I don't think its a valid approach.
A possible solution to omit Typescript checks is to access the property dynamically (Not telling wether its good).
myClass['privateProp'] or for methods: myClass['privateMethod']()
Technically, in current versions of TypeScript private methods are only compile-time checked to be private - so you can call them.
class Example {
public publicMethod() {
return 'public';
}
private privateMethod() {
return 'private';
}
}
const example = new Example();
console.log(example.publicMethod()); // 'public'
console.log(example.privateMethod()); // 'private'
I mention this only because you asked how to do it, and that is how you could do it.
Correct Answer
However, that private method must be called by some other method... otherwise it isn't called at all. If you test the behaviour of that other method, you will cover the private method in the context it is used.
If you specifically test private methods, your tests will become tightly coupled to the implementation details (i.e. a good test wouldn't need to be changed if you refactored the implementation).
Disclaimer
If you still test it at the private method level, the compiler might in the future change and make the test fail (i.e. if the compiler made the method "properly" private, or if a future version of ECMAScript added visibility keywords, etc).
In my case, I use the prototype of the object to get access to a private method. It works well and TS does not swear.
For example:
class Example {
private privateMethod() {}
}
describe() {
it('test', () => {
const example = new Example();
const exampleProto = Object.getPrototypeOf(example);
exampleProto.privateMethod();
})
}
If you use a static method then use exampleProto.constructor.privateMethod();.
In HolgerJeromin's comment, the comment issue has a succinct solution that still uses the property syntax.
The solution is to type cast your object / class to any.
Examples:
(<any>myClass).privateMethod();
const value = (<any>myClass).privateValue;
(myClass as any).privateMethod();
const value = (myClass as any).privateValue;
This method satisfies the compiler as well as the VSCode syntax highlighting.
Here are some of my notes from the issue that talks about this
Accessing via a string is more common, although I don't see why it might be more typesafe.
These features are done deliberately, therefore they are helping more than hindering.
There is probably a way to disable this type of feature so people don't copy and paste this code into production. "noImplicitAny": true, might help in the tsconfig.json
Extract out the private function into a separate/stand alone function, but don't export it externally.
This is somewhat semantically correct, since after all — a private function is private and should not be accessed by anyone except the class itself.
My subjective solution: you could define a new testing-only interface that extends the original one by adding the private methods as (implicitly public) interface methods. Then, you cast the instantiated object to this new test type. This satisfies both tsc and VS code type checking. Your example with my solution:
interface INotification {
validateTemplate(): boolean,
}
class Notification implements INotification {
constructor() {}
public validateTemplate() {
return true;
}
private replacePlaceholder() {
return true;
}
}
Testing:
import {Notification} from 'Notification';
import * as chai from "chai";
interface INotificationTest extends INotification {
replacePlaceholder(): boolean;
}
describe("Notification", function(){
describe('#validateTemplate - Validate template', function() {
it('it should return success', function() {
const result = new Notification() as INotificationTest;
chai.expect(result.validateTemplate()).to.be.equal(true);
});
});
describe('#replacePlaceholder - Replace Placeholder', function() {
it('it should return success', function() {
const result = new Notification() as INotificationTest;
// Works!
chai.expect(result.replacePlaceholder()).to.be.equal(true);
});
});
});
Advantages:
tsc and vs code do not complain
IntelliSense (or any other autocomplete) works
simple (subjectively)
If you don't want to define the original interface (INotification), you could just fully define the test one (INotificationTest) instead of extending and cast it in the same manner.
Disadvantages:
Added boilerplate
Need to have both of the interfaces updated and in sync
Potentially introducing bugs by explicitly casting as a non original type.
I leave it up to you to decide whether this is worth it or no. In my case, the positives outweigh the negatives. I have tested this with jest, but I assume that mocha.js is no different here.
Edit: but generally I would agree with Fenton's answer
// module.ts
private async privateMethod = () => "private method executed"
public async testPrivateMethods(...args) {
if (process.env.NODE_ENV === 'development') {
return this.privateMethod(...args);
}
}
Now we can reach our private method to test. In jest file:
// module.spec.js
describe('Module', () => {
let service: Module = new Module();
it('private method should be defined', () => {
expect(service.testPrivateMethods).toBeDefined();
});
}
You need to set your enviroment variable name of NODE_ENV must be development.
// .env
NODE_ENV="development"
The fun thing is that it's just a typescript error (not javascript), so you can fix it with
// #ts-expect-error
and everything works fine.
I consider it as a legitimate solution, as the goal was to suppress typescript in this particular case.
Since private methods are not accessible outside class, you can have another public method which calls replacePlaceholder() in Notification class and then test the public method.

How to unit test stateless service in service fabric

I want to create an instance of class A which inherits class StatelessService in my unit test. But I can't. I've tried everything: mocking dependencies, implementing my own contexts and etc.
When I try to create an instance, StatelessService throws NullReferenceException somewhere inside.
Can it be done at all?
class A : StatelessService
{
public A(StatelessServiceContext context) : base(context /* Here will be thrown NullReferenceException */)
{
// It will never even get there.
}
}
class UnitTest
{
public void TestMethod()
{
var activationContext = MOCK<ICodePackageActivationContext>();
var context = new StatelessServiceContext(..., activationContext, ...);
var a = new A(context); // Here will be thrown an exception.
}
}
It can be done. But instead of re inventing the wheel, have a look at service fabric mocks https://github.com/loekd/ServiceFabric.Mocks
It contains useful helpers for exactly your type of scenario.

Non virtual methods can not be intercepted

I am new to FakeItEasy and try solve a problem.
I have a class
public class Events
{
public List<Events> SaveEvents()
{
// Call to repository and return 1(success) or -1(fail)
//If the repository return 1 then need to make another call to save the action in db
//Sample Code here
AuditLogService log = new AuditLogService();
log.CallLog();
}
}
Here is the Test Code:
[TestMethod]
public void EventValidation()
{
//Arrange
var Fakeevents = A.Fake<Events>();
var log = A.Fake<AuditLogService>();
var _EventsController = new EventsController(Fakeevents);
_EventsController.SaveEvents();
A.CallTo(
() => Fakeevents.SaveEvents().Retunr(1).AssignsOutAndRefParameters(status)
A.CallTo(
() => log.CallLog()).MustHaveHappened(Repeated.AtLeast.Once);
}
I am getting error like "Non virtual methods can not be intercepted"
I want to check whether the Calllog method is called after success or not.
Can anyone please help me on this.
I have a method and inside a method i am initiating another class and calling a method of the class. I want to check from fakeItEasy whether the method is called.
Unfortunately, your title says it all. Non-virtual members cannot be faked, configured, or intercepted, as noted in the documentation under "What members can be overridden?".
There's nothing that FakeItEasy can do for you unless you make the member virtual (or promote it to an interface and fake the interface, or something similar).
Have you tried to use function?
Like this:
Func<YourReturnType> action = () => YourMethod(params); // Act
action.Should().Throw<Exception>(); // Assert
var log = A.Fake();
Use interface instead of AuditLogService. And have this class implement that interface
var log = A.Fake();

Derived Class Method of Generic Class Template not being called

I have a generic class for making and processing JSON API requests. I pass in the TParam and TResult template parameters but when I use a derived type it's implementation is not being called.
Here is some code you can throw in a playground to illustrate:
import Cocoa
// Base class for parameters to POST to service
class APIParams {
func getData() -> Dictionary<String, AnyObject> {
return Dictionary<String, AnyObject>()
}
}
// Base class for parsing a JSON Response
class APIResult {
func parseData(data: AnyObject?) {
}
}
// Derived example for a login service
class DerivedAPIParams: APIParams {
var user = "some#one.com"
var pass = "secret"
// THIS METHOD IS CALLED CORRECTLY
override func getData() -> Dictionary<String, AnyObject> {
return [ "user": user, "pass": pass ]
}
}
// Derived example for parsing a login response
class DerivedAPIResult: APIResult {
var success = false
var token:String? = ""
// THIS METHOD IS NEVER CALLED
override func parseData(data: AnyObject?) {
/*
self.success = data!.valueForKey("success") as Bool
self.token = data!.valueForKey("token") as? String
*/
self.success = true
self.token = "1234"
}
}
class APIOperation<TParams: APIParams, TResult: APIResult> {
var url = "http://localhost:3000"
func request(params: TParams, done: (NSError?, TResult?) -> ()) {
let paramData = params.getData()
// ... snip making a request to website ...
let result = self.parseResult(nil)
done(nil, result)
}
func parseResult(data: AnyObject?) -> TResult {
var result = TResult.self()
// This should call the derived implementation if passed, right?
result.parseData(data)
return result
}
}
let derivedOp = APIOperation<DerivedAPIParams, DerivedAPIResult>()
let params = DerivedAPIParams()
derivedOp.request(params) {(error, result) in
if result? {
result!.success
}
}
The really weird thing is that only the DerivedAPIResult.parseData() is not called, whereas the DerivedAPIParams.getData() method is called. Any ideas why?
UPDATE: This defect is fixed with XCode 6.3 beta1 (Apple Swift version 1.2 (swiftlang-602.0.37.3 clang-602.0.37))
Added info for a workaround when using XCode 6.1 (Swift 1.1)
See these dev forum threads for details:
https://devforums.apple.com/thread/251920?tstart=30
https://devforums.apple.com/message/1058033#1058033
In a very similar code sample I was having the exact same issue. After waiting through beta after beta for a "fix", I did more digging and discovered that I can get the expect results by making the base class init() required.
By way of example, here is Matt Gibson's reduced example "fixed" by adding the proper init() to ApiResult
// Base class for parsing a JSON Response
class APIResult {
// adding required init() to base class yields the expected behavior
required init() {}
}
// Derived example for parsing a login response
class DerivedAPIResult: APIResult {
}
class APIOperation<TResult: APIResult> {
init() {
// EDIT: workaround for xcode 6.1, tricking the compiler to do what we want here
let tResultClass : TResult.Type = TResult.self
var test = tResultClass()
// should be able to just do, but it is broken and acknowledged as such by Apple
// var test = TResult()
println(test.self) // now shows that we get DerivedAPIResult
}
}
// Templated creation creates APIResult
let derivedOp = APIOperation<DerivedAPIResult>()
I do not know why this works. If I get time I will dig deeper, but my best guess is that for some reason having required init is causing different object allocation/construction code to be generated that forces proper set up of the vtable we are hoping for.
Looks possibly surprising, certainly. I've reduced your case to something rather simpler, which might help to figure out what's going on:
// Base class for parsing a JSON Response
class APIResult {
}
// Derived example for parsing a login response
class DerivedAPIResult: APIResult {
}
class APIOperation<TResult: APIResult> {
init() {
var test = TResult()
println(test.self) // Shows that we get APIResult, not DerivedAPIResult
}
}
// Templated creation creates APIResult
let derivedOp = APIOperation<DerivedAPIResult>()
...so it seems that creating a new instance of a templated class with a type constraint gives you an instance of the constraint class, rather than the derived class you use to instantiate the specific template instance.
Now, I'd say that the generics in Swift, looking through the Swift book, would probably prefer you not to create your own instances of derived template constraint classes within the template code, but instead just define places to hold instances that are then passed in. By which I mean that this works:
// Base class for parsing a JSON Response
class APIResult {
}
// Derived example for parsing a login response
class DerivedAPIResult: APIResult {
}
class APIOperation<T: APIResult> {
var instance: T
init(instance: T) {
self.instance = instance
println(instance.self) // As you'd expect, this is a DerivedAPIResult
}
}
let derivedOpWithPassedInstance = APIOperation<DerivedAPIResult>(instance: DerivedAPIResult())
...but I'm not clear whether what you're trying should technically be allowed or not.
My guess is that the way generics are implemented means that there's not enough type information when creating the template to create objects of the derived type from "nothing" within the template—so you'd have to create them in your code, which knows about the derived type it wants to use, and pass them in, to be held by templated constrained types.
parseData needs to be defined as a class func which creates an instance of itself, assigns whatever instance properties, and then returns that instance. Basically, it needs to be a factory method. Calling .self() on the type is just accessing the type as a value, not an instance. I'm surprised you don't get some kind of error calling an instance method on a type.

Execute #PostLoad _after_ eagerly fetching?

Using JPA2/Hibernate, I've created an entity A that has a uni-directional mapping to an entity X (see below). Inside A, I also have a transient member "t" that I am trying to calculate using a #PostLoad method. The calculation requires access to the assosiated Xs:
#Entity
public class A {
// ...
#Transient
int t;
#OneToMany(orphanRemoval = false, fetch = FetchType.EAGER)
private List listOfX;
#PostLoad
public void calculateT() {
t = 0;
for (X x : listOfX)
t = t + x.someMethod();
}
}
However, when I try to load this entity, I get a "org.hibernate.LazyInitializationException: illegal access to loading collection" error.
at org.hibernate.collection.AbstractPersistentCollection.initialize(AbstractPersistentCollection.java:363)
at org.hibernate.collection.AbstractPersistentCollection.read(AbstractPersistentCollection.java:108)
at org.hibernate.collection.PersistentBag.get(PersistentBag.java:445)
at java.util.Collections$UnmodifiableList.get(Collections.java:1154)
at mypackage.A.calculateT(A.java:32)
Looking at hibernate's code (AbstractPersistentCollection.java) while debugging, I found that:
1) My #PostLoad method is called BEFORE the "listOfX" member is initialized
2) Hibernate's code has an explicit check to prevent initialization of an eagerly fetched collection during a #PostLoad:
protected final void initialize(boolean writing) {
if (!initialized) {
if (initializing) {
throw new LazyInitializationException("illegal access to loading collection");
}
throwLazyInitializationExceptionIfNotConnected();
session.initializeCollection(this, writing);
}
}
The only way I'm thinking to fix this is to stop using #PostLoad and move the initialization code into the getT() accessor, adding a synchronized block. However, I want to avoid that.
So, is there a way to have eager fetching executed prior to #PostLoad being called? I don't know of a JPA facility to do that, so I'm hoping there's something I don't know.
Also, perhaps Hibernate's proprietary API has something to control this behaviour?
This might be too late, but hibernate seems not to support the default jpa fetchtype option
#OneToMany(orphanRemoval = false, fetch = FetchType.EAGER)
You must use the hibernate specific one:
#LazyCollection(LazyCollectionOption.FALSE)
I don't know how to fix this but I think a little refactoring might help, the idea would be to move the code to a #PostConstruct
so for example your class would be:
#Entity
public class A {
// ...
#Transient
int t;
#OneToMany(orphanRemoval = false, fetch = FetchType.EAGER)
private List listOfX;
#PostConstruct
public void calculateT() {
t = 0;
for (X x : listOfX)
t = t + x.someMethod();
}
}
The server will call PostConstruct as soon as it has completed initializing all the container services for the bean.
Updated link to bug report:
https://hibernate.atlassian.net/browse/HHH-6043
This is fixed in 4.1.8 and 4.3.0 or later