Resolving constructor dependency on service used in NancyFX - ravendb

I have the following bootstrap
public class NancyBootStrapper: DefaultNancyBootstrapper
{
protected override void ConfigureRequestContainer(TinyIoC.TinyIoCContainer container, NancyContext context)
{
base.ConfigureRequestContainer(container, context);
var ravenSession = container.Resolve< IRavenSessionProvider >().GetSession();
container.Register( ravenSession );
}
}
When my Nancy app tries to instantiate BlogService using the following constructor
public BlogService(IDocumentSession documentSession)
{
this.documentSession = documentSession;
}
the application blows up stating that it can't resolve document session, I have also tried the following within my test method (removing the constructor injection).
public void BuildCategories()
{
var container = TinyIoCContainer.Current;
documentSession = container.Resolve< IDocumentSession >();
documentSession.Store(new Category{Title = "test"});
documentSession.Store(new Category{Title = ".net"});
documentSession.SaveChanges();
}
This also blows up, pointing out that it can't resolve documentSession.
Now this is the first time I have used either NancyFX or TinyIoC so I could be doing something fundamentally wrong though I should mention that the documentSession does resolve within a Nancy module..
Can any one offer a fix or some suggestions?

When is the BlogService supposed to be instantiated? -My guess would be once for the application, in which case I believe you are registering the session in the wrong bootstrapper method, and should do it in ConfigureApplicationContainer.

I've been playing & digging into both NancyFx and the TinyIoC code bases and have figured out how to fix this issue... I don't like the fix... but hay it works :)
Basically, I am creating a RavenDB document session in the bootstrapper method configureRequestContainer as it is best practice to use the request as your unit of work scope.
Unfortunately anything that is auto wired by tinyIoC within configureApplicationContainer does not have any constructor injection performed using the child container being used by the Nancy request (this includes those that are marked as MultiInstance or as PerRequestSingleton.
To get around this, you need to re-register any components that depend on your per request components within the same child container.
As I said, I don't like the fix, but it is ultimately a fix :)

Related

Unable to create a Role using RoleManager in Blazor Serverside

I had some code using the RoleManager that I had copied from an MVC project to create roles in a Blazor project.
It compiles okay but when I step through the code it gets to that line and then appears to throw and exception, as it doesn't ever go to the next line. I am unable to catch an exception though.
Since my code didn't work I found code on the web and it behaved the same, so I changed how it was injected and I got a different error, so I found a third way of doing it and that too gets to the line that tests to see if there is a role already existing and blows up.
Here is the latest attempt
[Inject]
IServiceProvider services {get;set;}
public async Task Initialize()
{
using (var roleManager = services.GetRequiredService<RoleManager<IdentityRole>>())
{
string proRole = "Pro";
if (!await roleManager.RoleExistsAsync(proRole))
{
var temp = await roleManager.CreateAsync(new IdentityRole { Name = proRole });
}
}
}
And it blows up on the awaited if statement.
Here is the previous code that should work that doesn't.
string proRole = "Pro";
string proClientRole = "ProClient";
if (!await _roleManager.RoleExistsAsync(proRole))
{
var temp = await _roleManager.CreateAsync(new IdentityRole { Name = proRole });
}
which is inside of a method.
I also had it as #{code in the Razor file and after an hour of trying different things there I moved it to a base class because they have been more stable in the past.
It is not the database connection because that is well verified and also because UserManager is called in the same class and it work
I also tried this code (Blazor Role Management Add Role trough UI (Crud)) both suggestions.
This is one bad thing about Blazor for me is it is buggy I never know if it is my bad, or just something wrong with the latest greatest. But I am assuming it is my bad in this case.
Anyway any help would be much appreciated, I am way too many hours on this,
I copy/pasted the same code to the "/" page and it works there.
For some reason it wouldn't work in a component loaded into a component but the standard Role code works as expected in the "/" page.
Most likely I should have restarted my computer as it now works in the original location too.

Blazor concurrency problem using Entity Framework Core

My goal
I want to create a new IdentityUser and show all the users already created through the same Blazor page. This page has:
a form through you will create an IdentityUser
a third-party's grid component (DevExpress Blazor DxDataGrid) that shows all users using UserManager.Users property. This component accepts an IQueryable as a data source.
Problem
When I create a new user through the form (1) I will get the following concurrency error:
InvalidOperationException: A second operation started on this context before a previous operation completed. Any instance members are not guaranteed to be thread-safe.
I think the problem is related to the fact that CreateAsync(IdentityUser user) and UserManager.Users are referring the same DbContext
The problem isn't related to the third-party's component because I reproduce the same problem replacing it with a simple list.
Step to reproduce the problem
create a new Blazor server-side project with authentication
change Index.razor with the following code:
#page "/"
<h1>Hello, world!</h1>
number of users: #Users.Count()
<button #onclick="#(async () => await Add())">click me</button>
<ul>
#foreach(var user in Users)
{
<li>#user.UserName</li>
}
</ul>
#code {
[Inject] UserManager<IdentityUser> UserManager { get; set; }
IQueryable<IdentityUser> Users;
protected override void OnInitialized()
{
Users = UserManager.Users;
}
public async Task Add()
{
await UserManager.CreateAsync(new IdentityUser { UserName = $"test_{Guid.NewGuid().ToString()}" });
}
}
What I noticed
If I change Entity Framework provider from SqlServer to Sqlite then the error will never show.
System info
ASP.NET Core 3.1.0 Blazor Server-side
Entity Framework Core 3.1.0 based on SqlServer provider
What I have already seen
Blazor A second operation started on this context before a previous operation completed: the solution proposed doesn't work for me because even if I change my DbContext scope from Scoped to Transient I still using the same instance of UserManager and its contains the same instance of DbContext
other guys on StackOverflow suggests creating a new instance of DbContext per request. I don't like this solution because it is against Dependency Injection principles. Anyway, I can't apply this solution because DbContext is wrapped inside UserManager
Create a generator of DbContext: this solution is pretty like the previous one.
Using Entity Framework Core with Blazor
Why I want to use IQueryable
I want to pass an IQueryable as a data source for my third-party's component because its can apply pagination and filtering directly to the Query. Furthermore IQueryable is sensitive to CUD
operations.
UPDATE (08/19/2020)
Here you can find the documentation about how to use Blazor and EFCore together
UPDATE (07/22/2020)
EFCore team introduces DbContextFactory inside Entity Framework Core .NET 5 Preview 7
[...] This decoupling is very useful for Blazor applications, where using IDbContextFactory is recommended, but may also be useful in other scenarios.
If you are interested you can read more at Announcing Entity Framework Core EF Core 5.0 Preview 7
UPDATE (07/06/2020)
Microsoft released a new interesting video about Blazor (both models) and Entity Framework Core. Please take a look at 19:20, they are talking about how to manage concurrency problem with EFCore
General solution
I asked Daniel Roth BlazorDeskShow - 2:24:20 about this problem and it seems to be a Blazor Server-Side problem by design.
DbContext default lifetime is set to Scoped. So if you have at least two components in the same page which are trying to execute an async query then we will encounter the exception:
InvalidOperationException: A second operation started on this context before a previous operation completed. Any instance members are not guaranteed to be thread-safe.
There are two workaround about this problem:
(A) set DbContext's lifetime to Transient
services.AddDbContext<ApplicationDbContext>(opt =>
opt.UseSqlServer(Configuration.GetConnectionString("DefaultConnection")), ServiceLifetime.Transient);
(B) as Carl Franklin suggested (after my question): create a singleton service with a static method which returns a new instance of DbContext.
anyway, each solution works because they create a new instance of DbContext.
About my problem
My problem wasn't strictly related to DbContext but with UserManager<TUser> which has a Scoped lifetime. Set DbContext's lifetime to Transient didn't solve my problem because ASP.NET Core creates a new instance of UserManager<TUser> when I open the session for the first time and it lives until I don't close it. This UserManager<TUser> is inside two components on the same page. Then we have the same problem described before:
two components that own the same UserManager<TUser> instance which contains a transient DbContext.
Currently, I solved this problem with another workaround:
I don't use UserManager<TUser> directly instead, I create a new instance of it through IServiceProvider and then it works. I am still looking for a method to change the UserManager's lifetime instead of using IServiceProvider.
tips: pay attention to services' lifetime
This is what I learned. I don't know if it is all correct or not.
I downloaded your sample and was able to reproduce your problem. The problem is caused because Blazor will re-render the component as soon as you await in code called from EventCallback (i.e. your Add method).
public async Task Add()
{
await UserManager.CreateAsync(new IdentityUser { UserName = $"test_{Guid.NewGuid().ToString()}" });
}
If you add a System.Diagnostics.WriteLine to the start of Add and to the end of Add, and then also add one at the top of your Razor page and one at the bottom, you will see the following output when you click your button.
//First render
Start: BuildRenderTree
End: BuildRenderTree
//Button clicked
Start: Add
(This is where the `await` occurs`)
Start: BuildRenderTree
Exception thrown
You can prevent this mid-method rerender like so....
protected override bool ShouldRender() => MayRender;
public async Task Add()
{
MayRender = false;
try
{
await UserManager.CreateAsync(new IdentityUser { UserName = $"test_{Guid.NewGuid().ToString()}" });
}
finally
{
MayRender = true;
}
}
This will prevent re-rendering whilst your method is running. Note that if you define Users as IdentityUser[] Users you will not see this problem because the array is not set until after the await has completed and is not lazy evaluated, so you don't get this reentrancy problem.
I believe you want to use IQueryable<T> because you need to pass it to 3rd party components. The problem is, different components can be rendered on different threads, so if you pass IQueryable<T> to other components then
They might render on different threads and cause the same problem.
They most likely will have an await in the code that consumes the IQueryable<T> and you'll have the same problem again.
Ideally, what you need is for the 3rd party component to have an event that asks you for data, giving you some kind of query definition (page number etc). I know Telerik Grid does this, as do others.
That way you can do the following
Acquire a lock
Run the query with the filter applied
Release the lock
Pass the results to the component
You cannot use lock() in async code, so you'd need to use something like SpinLock to lock a resource.
private SpinLock Lock = new SpinLock();
private async Task<WhatTelerikNeeds> ReadData(SomeFilterFromTelerik filter)
{
bool gotLock = false;
while (!gotLock) Lock.Enter(ref gotLock);
try
{
IUserIdentity result = await ApplyFilter(MyDbContext.Users, filter).ToArrayAsync().ConfigureAwait(false);
return new WhatTelerikNeeds(result);
}
finally
{
Lock.Exit();
}
}
Perhaps not the best approach but rewriting async method as non-async fixes the problem:
public void Add()
{
Task.Run(async () =>
await UserManager.CreateAsync(new IdentityUser { UserName = $"test_{Guid.NewGuid().ToString()}" }))
.Wait();
}
It ensures that UI is updated only after the new user is created.
The whole code for Index.razor
#page "/"
#inherits OwningComponentBase<UserManager<IdentityUser>>
<h1>Hello, world!</h1>
number of users: #Users.Count()
<button #onclick="#Add">click me. I work if you use Sqlite</button>
<ul>
#foreach(var user in Users.ToList())
{
<li>#user.UserName</li>
}
</ul>
#code {
IQueryable<IdentityUser> Users;
protected override void OnInitialized()
{
Users = Service.Users;
}
public void Add()
{
Task.Run(async () => await Service.CreateAsync(new IdentityUser { UserName = $"test_{Guid.NewGuid().ToString()}" })).Wait();
}
}
I found your question looking for answers about the same error message you had.
My concurrency issue appears to have been due to a change that triggered a re-rendering of the visual tree to occur at the same time as (or due to the fact that) I was trying to call DbContext.SaveChangesAsync().
I solved this by overriding my component's ShouldRender() method like this:
protected override bool ShouldRender()
{
if (_updatingDb)
{
return false;
}
else
{
return base.ShouldRender();
}
}
I then wrapped my SaveChangesAsync() call in code that set a private bool field _updatingDb appropriately:
try
{
_updatingDb = true;
await DbContext.SaveChangesAsync();
}
finally
{
_updatingDb = false;
StateHasChanged();
}
The call to StateHasChanged() may or may not be necessary, but I've included it just in case.
This fixed my issue, which was related to selectively rendering a bound input tag or just text depending on if the data field was being edited. Other readers may find that their concurrency issue is also related to something triggering a re-render. If so, this technique may be helpful.
Well, I have a quite similar scenario with this, and I 'solve' mine is to move everything from OnInitializedAsync() to
protected override async Task OnAfterRenderAsync(bool firstRender)
{
if(firstRender)
{
//Your code in OnInitializedAsync()
StateHasChanged();
}
{
It seems solved, but I had no idea to find out the proves. I guess just skip from the initialization to let the component success build, then we can go further.
/******************************Update********************************/
I'm still facing the problem, seems I'm giving a wrong solution to go. When I checked with this Blazor A second operation started on this context before a previous operation completed I got my problem clear. Cause I'm actually dealing with a lot of components initialization with dbContext operations. According to #dani_herrera mention that if you have more than 1 component execute Init at a time, probably the problem appears.
As I took his advise to change my dbContext Service to Transient, and I get away from the problem.
#Leonardo Lurci Had covered conceptually. If you guys are not yet wanting to move to .NET 5.0 preview, i would recommend looking at Nuget package 'EFCore.DbContextFactory', documentation is pretty neat. Essential it emulates AddDbContextFactory. Ofcourse, it creates a context per component.
So far, this is working fine for me so far without any problems...
I ensure single-threaded access by only interacting with my DbContext via a new DbContext.InvokeAsync method, which uses a SemaphoreSlim to ensure only a single operation is performed at a time.
I chose SemaphoreSlim because you can await it.
Instead of this
return Db.Users.FirstOrDefaultAsync(x => x.EmailAddress == emailAddress);
do this
return Db.InvokeAsync(() => ...the query above...);
// Add the following methods to your DbContext
private SemaphoreSlim Semaphore { get; } = new SemaphoreSlim(1);
public TResult Invoke<TResult>(Func<TResult> action)
{
Semaphore.Wait();
try
{
return action();
}
finally
{
Semaphore.Release();
}
}
public async Task<TResult> InvokeAsync<TResult>(Func<Task<TResult>> action)
{
await Semaphore.WaitAsync();
try
{
return await action();
}
finally
{
Semaphore.Release();
}
}
public Task InvokeAsync(Func<Task> action) =>
InvokeAsync<object>(async () =>
{
await action();
return null;
});
public void InvokeAsync(Action action) =>
InvokeAsync(() =>
{
action();
return Task.CompletedTask;
});
#Leonardo Lurci has a great answer with multiple solutions to the problem. I will give my opinion about every solution and which I think it is the best one.
Making DBContext transient - it is a solution but it is not optimized for this cases..
Carl Franklin suggestion - the singleton service will not be able to control the lifetime of the context and will depend on the service requester to dispose the context after use.
Microsoft documentation they talk about injecting DBContext Factory into a component with the IDisposable interface to Dispose the context when the component is destroied. This is not a very good solution, because a lot of problems happen with it, like: performing a context operation and leaving the component before it finishes that operation, will dispose the context and throw exception..
Finally. The best solution so far is to inject the DBContext Factory in the component yes, but whenever you need it, you create a new instance with using statement like bellow:
public async Task GetSomething()
{
using var context = DBFactory.CreateDBContext();
return await context.Something.ToListAsync();
}
Since DbFactory is optimazed when creating new context instances, there is no significante overhead, making it a better choice and better performing than Transient context, it also disposes the context at the end of the method because of "using" statement.
Hope it was useful.

Ninject Inject Common DbContext Into Numerous Repositories

There’s something which I am doing that is working, but I think it can probably be done a lot better (and therefore, with more maintainability).
I am using Ninject to inject various things into a controller. The problem which I needed to solve is that the DbContext for each repository needed to be the same. That is, the same object in memory.
Whilst, the following code does achieve that, my Ninject common config file has started to get quite messy as I have to write similar code for each controller:
kernel.Bind<OrderController>().ToMethod(ctx =>
{
var sharedContext = ctx.Kernel.Get<TTSWebinarsContext>();
var userAccountService = kernel.Get<UserAccountService>();
ILogger logger = new Log4NetLogger(typeof(Nml.OrderController));
ILogger loggerForOrderManagementService = new Log4NetLogger(typeof(OrderManagementService));
var orderManagementService = new OrderManagementService(
new AffiliateRepository(sharedContext),
new RegTypeRepository(sharedContext),
new OrderRepository(sharedContext),
new RefDataRepository(),
new WebUserRepository(sharedContext),
new WebinarRepository(sharedContext),
loggerForOrderManagementService,
ttsConfig
);
var membershipService = new MembershipService(
new InstitutionRepository(sharedContext),
new RefDataRepository(),
new SamAuthenticationService(userAccountService),
userAccountService,
new WebUserRepository(sharedContext)
);
return new OrderController(membershipService, orderManagementService, kernel.Get<IStateService>(), logger);
}).InRequestScope();
Is there a neater way of doing this?
Edit
Tried the following code. As soon as I make a second request, an exception is chucked that the DbContext has already been disposed.
kernel.Bind<TTSWebinarsContext>().ToSelf().InRequestScope();
string baseUrl = HttpRuntime.AppDomainAppPath;
kernel.Bind<IStateService>().To<StateService>().InRequestScope();
kernel.Bind<IRefDataRepository>().To<RefDataRepository>().InRequestScope().WithConstructorArgument("context", kernel.Get<TTSWebinarsContext>());
var config = MembershipRebootConfig.Create(baseUrl, kernel.Get<IStateService>(), kernel.Get<IRefDataRepository>());
var ttsConfig = TtsConfig.Create(baseUrl);
kernel.Bind<MembershipRebootConfiguration>().ToConstant(config);
kernel.Bind<TtsConfiguration>().ToConstant(ttsConfig);
kernel.Bind<IAffiliateRepository>().To<AffiliateRepository>().InRequestScope().WithConstructorArgument("context", kernel.Get<TTSWebinarsContext>());
kernel.Bind<IWebinarRepository>().To<WebinarRepository>().InRequestScope().WithConstructorArgument("context", kernel.Get<TTSWebinarsContext>());
kernel.Bind<IWebUserRepository>().To<WebUserRepository>().InRequestScope().WithConstructorArgument("context", kernel.Get<TTSWebinarsContext>());
kernel.Bind<IOrderRepository>().To<OrderRepository>().InRequestScope().WithConstructorArgument("context", kernel.Get<TTSWebinarsContext>());
kernel.Bind<IInstitutionRepository>().To<InstitutionRepository>().WithConstructorArgument("context", kernel.Get<TTSWebinarsContext>());
kernel.Bind<IUserAccountRepository>().To<DefaultUserAccountRepository>().InRequestScope();
kernel.Bind<IRegTypeRepository>().To<RegTypeRepository>().InRequestScope().WithConstructorArgument("context", kernel.Get<TTSWebinarsContext>());
kernel.Bind<UserAccountService>().ToMethod(ctx =>
{
var userAccountService = new UserAccountService(config, ctx.Kernel.Get<IUserAccountRepository>());
return userAccountService;
});
kernel.Bind<IOrderManagementService>().To<OrderManagementService>().InRequestScope();
//RegisterControllers(kernel, ttsConfig);
kernel.Bind<AuthenticationService>().To<SamAuthenticationService>().InRequestScope();
kernel.Bind<IMembershipService>().To<MembershipService>().InRequestScope();
There's something about InRequestScope I'm misunderstanding.
Edit:
.InRequestScope() will ensure everything which gets injected that binding will receive exactly the same instance when during injection (creation) the HttpContext.Current is the same. That means when a client makes a request and the kernel is asked to provide instances with .InRequestScope(), it will return the same instance for the exact same request. Now when a client makes another request, another unique instance will be created.
When the request ends, ninject will dispose the instance in case it implements IDisposable.
However consider the following scenario:
public class A
{
private readonly DbContext dbContext;
public A(DbContext dbContext)
{
this.dbContext = dbContext;
}
}
and binding:
IBindingRoot.Bind<DbContext>().ToSelf().InRequestScope();
IBindingRoot.Bind<A>().ToSelf().InSingletonScope();
You got yourself a major problem. There's two scenarios how this can pan out:
You are trying to create an A outside of a request. It will fail. Instantiating the DbContext, ninject will look for HttpContext.Current - which is null at the time - and throw an Exception.
You are trying to create an A during a request. Instantiating will succeed. However, When you try to use some functionality of A (which is accessing DbContext in turn) after the request or during a new request, it will throw an ObjectDisposedException
To sum it up, an ObjectDisposedException when you access the DbContext can only be caused by two scenarios:
-you ar disposing the DbContext (or some component which in turn disposes the DbContext) before the request is over.
-you are keeping a reference to the DbContext (again, or to some component which in turn references the DbContext) across request boundaries.
That's it. Nothing complicated about this, but your object graph.
So what would help is drawing an object graph. Start from the root / request root. Then when you're done, start from the DbContext and check who's calling Dispose() on it. If there is no usage inside your code, it must be Ninject who's cleaning up when the request ends. That means, you need to check all references to the DbContext. Someone is keeping a reference across requests.
Original Answer:
You should look into scopes: https://github.com/ninject/ninject/wiki/Object-Scopes
Specifically, .InRequestScope() - or in case that is not appliccable to your problem - .InCallScope() should be interesting to you.
As you are already using .InRequestScope() for the original binding, i suggest that binding the shared context type also .InRequestScope() should be sufficient. It means every dependency of the OrderController will receive the same webinar context instance. Furthermore, if someone else in the same request wants to get a webinar context injected, he will also get the same instance.
You should look into scopes: https://github.com/ninject/ninject/wiki/Object-Scopes
Specifically, .InRequestScope() - or in case that is not appliccable to your problem - .InCallScope() should be interesting to you.
As you are already using .InRequestScope() for the original binding, i suggest that binding the shared context type also .InRequestScope() should be sufficient. It means every dependency of the OrderController will receive the same webinar context instance. Furthermore, if someone else in the same request wants to get a webinar context injected, he will also get the same instance.

Autofac / MVC4 / WebApi (RC) Dependency Injection issue after upgrading from beta

var resolver = new AutofacWebApiDependencyResolver(container);
configuration.ServiceResolver.SetResolver(resolver);
after updating to ASP.NET MVC4 (RC) I get the following error:
'System.Web.Http.HttpConfiguration' does not contain a definition for
'ServiceResolver' and no extension method 'ServiceResolver' accepting
a first argument of type 'System.Web.Http.HttpConfiguration' could be
found (are you missing a using directive or an assembly reference?)
I realize after reading this (http://www.asp.net/web-api/overview/extensibility/using-the-web-api-dependency-resolver) that these interfaces have changed, but I am not sure how to apply this change to how I use Autofac.
Do i need to wait for a new release from Autofac or is there another way I can get past this.
Edit:
As James Bradt mentions in his post below, the Autofac package has now been updated to fix this issue, so anyone coming across this thread in the future should probably try the new package first :)
Basically, with the new package you just need to do this in your global.asax.cs:
GlobalConfiguration.Configuration.DependencyResolver = new Autofac.Integration.WebApi.AutofacWebApiDependencyResolver(container);
/Edit
I just came across the same issue - I was able to resolve it in my situation by creating a simple IDependencyResolver implementation that wraps the existing AutofacDependencyResolver.
As the class name suggests, I'm treating this as a temporary resolution - the BeginScope and Dispose methods will need some work and are obviously not suitable for a production environment but this allows me to continue development until a proper solution emerges.
So, with those caveats, the IDependencyResolver implementation looks like this:
public class TemporaryDependencyResolver : IDependencyResolver
{
private readonly AutofacDependencyResolver _autofacDependencyResolver;
public TemporaryDependencyResolver(AutofacDependencyResolver autofacDependencyResolver)
{
_autofacDependencyResolver = autofacDependencyResolver;
}
public void Dispose()
{
}
public object GetService(Type serviceType)
{
return _autofacDependencyResolver.GetService(serviceType);
}
public IEnumerable<object> GetServices(Type serviceType)
{
return _autofacDependencyResolver.GetServices(serviceType);
}
public IDependencyScope BeginScope()
{
return this;
}
}
and I set it like this in Global.asax.cs:
var container = builder.Build();
var resolver = new AutofacDependencyResolver(container);
GlobalConfiguration.Configuration.DependencyResolver = new TemporaryDependencyResolver(resolver);
The AutoFac.WebApi package has been updated to (RC) - version 2.6.2.859
This appears to have been adjusted for the change in the dependencies between RC and Beta
I tried above solutions but didn't worked for me. Removing and Reinstalling these 2 specific packages solved the issue for me.
Microsoft.AspNet.WebApi.Tracing
Microsoft.AspNet.WebApi.OData

How do you set a custom session when unit testing with wicket?

I'm trying to run some unit tests on a wicket page that only allows access after you've logged in. In my JUnit test I cannot start the page or render it without setting the session.
How do you set the session? I'm having problems finding any documentation on how to do this.
WicketTester tester = new WicketTester(new MyApp());
((MyCustomSession)tester.getWicketSession()).setItem(MyFactory.getItem("abc"));
//Fails to start below, no session seems to be set
tester.startPage(General.class);
tester.assertRenderedPage(General.class);
What I frequently do is to provide a fake WebApplication with overrides for things that I want to mock or stub.
Among the things I override is the method
public abstract Session newSession(Request request, Response response);
which allows you to return a fake session setup with anything you want.
This is in Wicket 1.3 - if you're using 1.4, some of this may have changed, and as noted in another response, it may be related to a wicket bug.
But assuming the interface hasn't changed too much, overriding this method may also be another way of working around the issue in WICKET-1215.
You may be running into WICKET-1215. Otherwise what you're doing looks fine. For example, I have a Junit4 setup method that looks like:
#Before
public void createTester() {
tester = new WicketTester( new MyApp() );
// see http://issues.apache.org/jira/browse/WICKET-1215
tester.setupRequestAndResponse();
MyAppSession session = (MyAppSession) tester.getWicketSession();
session.setLocale(Locale.CANADA);
session.setUser(...);
}
Using Wicket 1.4, I use my normal WebApplication and WebSession implementations, called NewtEditor and NewtSession in my app. I override newSession, where I do the same than in the regular app code, except that I sign in right away. I also override newSessionStore for performance reasons, I copied this trick from WicketTesters code.
tester = new WicketTester(new NewtEditor()
{
#Override
public Session newSession(Request request, Response response)
{
NewtSession session = new NewtSession(request);
session.signIn(getTestDao());
return session;
}
#Override
protected ISessionStore newSessionStore()
{
// Copied from WicketTester: Don't use a filestore, or we spawn lots of threads,
// which makes things slow.
return new HttpSessionStore(this);
}
});