The application was developed on ASP NET Core 3. To log user actions, I decided to use a single method in the Project class. Faced the problem of using one singleton dbContext from different threads.
Startup.cs
public void ConfigureServices(IServiceCollection services)
{
string connection = Configuration.GetConnectionString("ConnectionDB");
services.AddDbContext<DataBaseContext>(options => options.UseSqlServer(connection), ServiceLifetime.Transient, ServiceLifetime.Singleton);
services.AddSingleton<Project>();
}
Project.cs
public async Task AddUserLog(string action, string message, int userId)
{
try
{
UserLog userLog = new UserLog()
{
Action = action,
Message = message,
UserId = userId
Datepoint = DateTime.Now
};
_dbContext.UserLog.Add(userLog);
await _dbContext.SaveChangesAsync();
}
catch (Exception ex)
{
await AddSystemLog("Project", "AddUserLog", ex.Message);
}
}
SchemeController.cs
public class SchemeController : ControllerBase
{
private readonly Project _project;
public SchemeController(Project project)
{
_project = project;
}
[Authorize(Policy = "AdvancedControl")]
[HttpPost("[action]")]
public async Task SomeMethode()
{
for (int i = 0; i < 10; i++)
{
await _project.AddUserLog("Text", "Message", 42);
}
}
}
Already at the second iteration of the loop, I catch an exception in the AddUserLog method:
"A second operation started on this context before a previous operation completed. This is usually caused by different threads using the same instance of DbContext."
I suggest several solutions:
Add the log to the buffer table and then save it to the database by timer. But this is not the best way out;
Block the method while it is being saved to the database.
But I don’t like any of the options.
Please tell me the correct approach in solving this issue.
So, you trying to use shared resource (singleton Project class) to perform parallel operations (save UserLogs) while your shared resource implementation is not thread-safe (exceptions raised).
You have at lease three ways to solve this:
Do not use shared resource: register Project per scope instead of singletone;
Do not perform operations in parallel: seems hard to achieve because you making webapp and you can't force user(s) to wait
Refactor your resource to be thread-safe: add locks/mutexes/buffering... inside Project
There is no one "correct" way - all 3 are correct. Choose one you like (or combine several).
Usually using scoped dbcontext is recommended (because connections are pooled), but it's the creator of app who should decide.
How can I pass along auditing information between clients and services in an easy way without having to add that information as arguments for all service methods? Can I use message headers to set this data for a call?
Is there a way to allow service to pass that along downstream also, i.e., if ServiceA calls ServiceB that calls ServiceC, could the same auditing information be send to first A, then in A's call to B and then in B's call to C?
There is actually a concept of headers that are passed between client and service if you are using fabric transport for remoting. If you are using Http transport then you have headers there just as you would with any http request.
Note, below proposal is not the easiest solution, but it solves the issue once it is in place and it is easy to use then, but if you are looking for easy in the overall code base this might not be the way to go. If that is the case then I suggest you simply add some common audit info parameter to all your service methods. The big caveat there is of course when some developer forgets to add it or it is not set properly when calling down stream services. It's all about trade-offs, as alway in code :).
Down the rabbit hole
In fabric transport there are two classes that are involved in the communication: an instance of a IServiceRemotingClient on the client side, and an instance of IServiceRemotingListener on the service side. In each request from the client the messgae body and ServiceRemotingMessageHeaders are sent. Out of the box these headers include information of which interface (i.e. which service) and which method are being called (and that's also how the underlying receiver knows how to unpack that byte array that is the body). For calls to Actors, which goes through the ActorService, additional Actor information is also included in those headers.
The tricky part is hooking into that exchange and actually setting and then reading additional headers. Please bear with me here, it's a number of classes involved in this behind the curtains that we need to understand.
The service side
When you setup the IServiceRemotingListener for your service (example for a Stateless service) you usually use a convenience extension method, like so:
protected override IEnumerable<ServiceInstanceListener> CreateServiceInstanceListeners()
{
yield return new ServiceInstanceListener(context =>
this.CreateServiceRemotingListener(this.Context));
}
(Another way to do it would be to implement your own listener, but that's not really what we wan't to do here, we just wan't to add things on top of the existing infrastructure. See below for that approach.)
This is where we can provide our own listener instead, similar to what that extention method does behind the curtains. Let's first look at what that extention method does. It goes looking for a specific attribute on assembly level on your service project: ServiceRemotingProviderAttribute. That one is abstract, but the one that you can use, and which you will get a default instance of, if none is provided, is FabricTransportServiceRemotingProviderAttribute. Set it in AssemblyInfo.cs (or any other file, it's an assembly attribute):
[assembly: FabricTransportServiceRemotingProvider()]
This attribute has two interesting overridable methods:
public override IServiceRemotingListener CreateServiceRemotingListener(
ServiceContext serviceContext, IService serviceImplementation)
public override IServiceRemotingClientFactory CreateServiceRemotingClientFactory(
IServiceRemotingCallbackClient callbackClient)
These two methods are responsible for creating the the listener and the client factory. That means that it is also inspected by the client side of the transaction. That is why it is an attribute on assembly level for the service assembly, the client side can also pick it up together with the IService derived interface for the client we want to communicate with.
The CreateServiceRemotingListener ends up creating an instance FabricTransportServiceRemotingListener, however in this implementation we cannot set our own specific IServiceRemotingMessageHandler. If you create your own sub class of FabricTransportServiceRemotingProviderAttribute and override that then you can actually make it create an instance of FabricTransportServiceRemotingListener that takes in a dispatcher in the constructor:
public class AuditableFabricTransportServiceRemotingProviderAttribute :
FabricTransportServiceRemotingProviderAttribute
{
public override IServiceRemotingListener CreateServiceRemotingListener(
ServiceContext serviceContext, IService serviceImplementation)
{
var messageHandler = new AuditableServiceRemotingDispatcher(
serviceContext, serviceImplementation);
return (IServiceRemotingListener)new FabricTransportServiceRemotingListener(
serviceContext: serviceContext,
messageHandler: messageHandler);
}
}
The AuditableServiceRemotingDispatcher is where the magic happens. It is our own ServiceRemotingDispatcher subclass. Override the RequestResponseAsync (ignore HandleOneWay, it is not supported by service remoting, it throws an NotImplementedException if called), like this:
public class AuditableServiceRemotingDispatcher : ServiceRemotingDispatcher
{
public AuditableServiceRemotingDispatcher(ServiceContext serviceContext, IService service) :
base(serviceContext, service) { }
public override async Task<byte[]> RequestResponseAsync(
IServiceRemotingRequestContext requestContext,
ServiceRemotingMessageHeaders messageHeaders,
byte[] requestBodyBytes)
{
byte[] userHeader = null;
if (messageHeaders.TryGetHeaderValue("user-header", out auditHeader))
{
// Deserialize from byte[] and handle the header
}
else
{
// Throw exception?
}
byte[] result = null;
result = await base.RequestResponseAsync(requestContext, messageHeaders, requestBodyBytes);
return result;
}
}
Another, easier, but less flexible way, would be to directly create an instance of FabricTransportServiceRemotingListener with an instance of our custom dispatcher directly in the service:
protected override IEnumerable<ServiceInstanceListener> CreateServiceInstanceListeners()
{
yield return new ServiceInstanceListener(context =>
new FabricTransportServiceRemotingListener(this.Context, new AuditableServiceRemotingDispatcher(context, this)));
}
Why is this less flexible? Well, because using the attribute supports the client side as well, as we see below
The client side
Ok, so now we can read custom headers when receiving messages, how about setting those? Let's look at the other method of that attribute:
public override IServiceRemotingClientFactory CreateServiceRemotingClientFactory(IServiceRemotingCallbackClient callbackClient)
{
return (IServiceRemotingClientFactory)new FabricTransportServiceRemotingClientFactory(
callbackClient: callbackClient,
servicePartitionResolver: (IServicePartitionResolver)null,
traceId: (string)null);
}
Here we cannot just inject a specific handler or similar as for the service, we have to supply our own custom factory. In order not to have to reimplement the particulars of FabricTransportServiceRemotingClientFactory I simply encapsulate it in my own implementation of IServiceRemotingClientFactory:
public class AuditedFabricTransportServiceRemotingClientFactory : IServiceRemotingClientFactory, ICommunicationClientFactory<IServiceRemotingClient>
{
private readonly ICommunicationClientFactory<IServiceRemotingClient> _innerClientFactory;
public AuditedFabricTransportServiceRemotingClientFactory(ICommunicationClientFactory<IServiceRemotingClient> innerClientFactory)
{
_innerClientFactory = innerClientFactory;
_innerClientFactory.ClientConnected += OnClientConnected;
_innerClientFactory.ClientDisconnected += OnClientDisconnected;
}
private void OnClientConnected(object sender, CommunicationClientEventArgs<IServiceRemotingClient> e)
{
EventHandler<CommunicationClientEventArgs<IServiceRemotingClient>> clientConnected = this.ClientConnected;
if (clientConnected == null) return;
clientConnected((object)this, new CommunicationClientEventArgs<IServiceRemotingClient>()
{
Client = e.Client
});
}
private void OnClientDisconnected(object sender, CommunicationClientEventArgs<IServiceRemotingClient> e)
{
EventHandler<CommunicationClientEventArgs<IServiceRemotingClient>> clientDisconnected = this.ClientDisconnected;
if (clientDisconnected == null) return;
clientDisconnected((object)this, new CommunicationClientEventArgs<IServiceRemotingClient>()
{
Client = e.Client
});
}
public async Task<IServiceRemotingClient> GetClientAsync(
Uri serviceUri,
ServicePartitionKey partitionKey,
TargetReplicaSelector targetReplicaSelector,
string listenerName,
OperationRetrySettings retrySettings,
CancellationToken cancellationToken)
{
var client = await _innerClientFactory.GetClientAsync(
serviceUri,
partitionKey,
targetReplicaSelector,
listenerName,
retrySettings,
cancellationToken);
return new AuditedFabricTransportServiceRemotingClient(client);
}
public async Task<IServiceRemotingClient> GetClientAsync(
ResolvedServicePartition previousRsp,
TargetReplicaSelector targetReplicaSelector,
string listenerName,
OperationRetrySettings retrySettings,
CancellationToken cancellationToken)
{
var client = await _innerClientFactory.GetClientAsync(
previousRsp,
targetReplicaSelector,
listenerName,
retrySettings,
cancellationToken);
return new AuditedFabricTransportServiceRemotingClient(client);
}
public Task<OperationRetryControl> ReportOperationExceptionAsync(
IServiceRemotingClient client,
ExceptionInformation exceptionInformation,
OperationRetrySettings retrySettings,
CancellationToken cancellationToken)
{
return _innerClientFactory.ReportOperationExceptionAsync(
client,
exceptionInformation,
retrySettings,
cancellationToken);
}
public event EventHandler<CommunicationClientEventArgs<IServiceRemotingClient>> ClientConnected;
public event EventHandler<CommunicationClientEventArgs<IServiceRemotingClient>> ClientDisconnected;
}
This implementation simply passes along anything heavy lifting to the underlying factory, while returning it's own auditable client that similarily encapsulates a IServiceRemotingClient:
public class AuditedFabricTransportServiceRemotingClient : IServiceRemotingClient, ICommunicationClient
{
private readonly IServiceRemotingClient _innerClient;
public AuditedFabricTransportServiceRemotingClient(IServiceRemotingClient innerClient)
{
_innerClient = innerClient;
}
~AuditedFabricTransportServiceRemotingClient()
{
if (this._innerClient == null) return;
var disposable = this._innerClient as IDisposable;
disposable?.Dispose();
}
Task<byte[]> IServiceRemotingClient.RequestResponseAsync(ServiceRemotingMessageHeaders messageHeaders, byte[] requestBody)
{
messageHeaders.SetUser(ServiceRequestContext.Current.User);
messageHeaders.SetCorrelationId(ServiceRequestContext.Current.CorrelationId);
return this._innerClient.RequestResponseAsync(messageHeaders, requestBody);
}
void IServiceRemotingClient.SendOneWay(ServiceRemotingMessageHeaders messageHeaders, byte[] requestBody)
{
messageHeaders.SetUser(ServiceRequestContext.Current.User);
messageHeaders.SetCorrelationId(ServiceRequestContext.Current.CorrelationId);
this._innerClient.SendOneWay(messageHeaders, requestBody);
}
public ResolvedServicePartition ResolvedServicePartition
{
get { return this._innerClient.ResolvedServicePartition; }
set { this._innerClient.ResolvedServicePartition = value; }
}
public string ListenerName
{
get { return this._innerClient.ListenerName; }
set { this._innerClient.ListenerName = value; }
}
public ResolvedServiceEndpoint Endpoint
{
get { return this._innerClient.Endpoint; }
set { this._innerClient.Endpoint = value; }
}
}
Now, in here is where we actually (and finally) set the audit name that we want to pass along to the service.
Call chains and service request context
One final piece of the puzzle, the ServiceRequestContext, which is a custom class that allows us to handle an ambient context for a service request call. This is relevant because it gives us an easy way to propagate that context information, like the user or a correlation id (or any other header information we want to pass between client and service), in a chain of calls. The implementation ServiceRequestContext looks like:
public sealed class ServiceRequestContext
{
private static readonly string ContextKey = Guid.NewGuid().ToString();
public ServiceRequestContext(Guid correlationId, string user)
{
this.CorrelationId = correlationId;
this.User = user;
}
public Guid CorrelationId { get; private set; }
public string User { get; private set; }
public static ServiceRequestContext Current
{
get { return (ServiceRequestContext)CallContext.LogicalGetData(ContextKey); }
internal set
{
if (value == null)
{
CallContext.FreeNamedDataSlot(ContextKey);
}
else
{
CallContext.LogicalSetData(ContextKey, value);
}
}
}
public static Task RunInRequestContext(Func<Task> action, Guid correlationId, string user)
{
Task<Task> task = null;
task = new Task<Task>(async () =>
{
Debug.Assert(ServiceRequestContext.Current == null);
ServiceRequestContext.Current = new ServiceRequestContext(correlationId, user);
try
{
await action();
}
finally
{
ServiceRequestContext.Current = null;
}
});
task.Start();
return task.Unwrap();
}
public static Task<TResult> RunInRequestContext<TResult>(Func<Task<TResult>> action, Guid correlationId, string user)
{
Task<Task<TResult>> task = null;
task = new Task<Task<TResult>>(async () =>
{
Debug.Assert(ServiceRequestContext.Current == null);
ServiceRequestContext.Current = new ServiceRequestContext(correlationId, user);
try
{
return await action();
}
finally
{
ServiceRequestContext.Current = null;
}
});
task.Start();
return task.Unwrap<TResult>();
}
}
This last part was much influenced by the SO answer by Stephen Cleary. It gives us an easy way to handle the ambient information down a hierarcy of calls, weather they are synchronous or asyncronous over Tasks. Now, with this we have a way of setting that information also in the Dispatcher on the service side:
public override Task<byte[]> RequestResponseAsync(
IServiceRemotingRequestContext requestContext,
ServiceRemotingMessageHeaders messageHeaders,
byte[] requestBody)
{
var user = messageHeaders.GetUser();
var correlationId = messageHeaders.GetCorrelationId();
return ServiceRequestContext.RunInRequestContext(async () =>
await base.RequestResponseAsync(
requestContext,
messageHeaders,
requestBody),
correlationId, user);
}
(GetUser() and GetCorrelationId() are just helper methods that gets and unpacks the headers set by the client)
Having this in place means that any new client created by the service for any aditional call will also have the sam headers set, so in the scenario ServiceA -> ServiceB -> ServiceC we will still have the same user set in the call from ServiceB to ServiceC.
what? that easy? yes ;)
From inside a service, for instance a Stateless OWIN web api, where you first capture the user information, you create an instance of ServiceProxyFactoryand wrap that call in a ServiceRequestContext:
var task = ServiceRequestContext.RunInRequestContext(async () =>
{
var serviceA = ServiceProxyFactory.CreateServiceProxy<IServiceA>(new Uri($"{FabricRuntime.GetActivationContext().ApplicationName}/ServiceA"));
await serviceA.DoStuffAsync(CancellationToken.None);
}, Guid.NewGuid(), user);
Ok, so to sum it up - you can hook into the service remoting to set your own headers. As we see above there is some work that needs to be done to get a mechanism for that in place, mainly creating your own subclasses of the underlying infrastructure. The upside is that once you have this in place, then you have a very easy way for auditing your service calls.
We have an Azure web role deployed that has been using Application Insights (ver. 1.0.0.4220), however, we're going over our data quota. Is it possible to configure Application Insights ignore a specific URL?
We have a status web service that gets a huge amount of traffic but never throws any errors. If I could exclude this one service URL I could cut my data usage in half.
Out of the box it is not supported. Sampling feature is coming but that would not be configurable by specific url. You can implement your own channel that would have your custom filtering. Basically your channel will get event to be sent, you check if you want to send it or not and then if yes pass to standard AI channel. Here you can read more about custom channels.
There are two things that changed since this blog post has been written:
channel should implement only ITelemetryChannel interface (ISupportConfiguration was removed)
and instead of PersistenceChannel you should use Microsoft.ApplicationInsights.Extensibility.Web.TelemetryChannel
UPDATE: Latest version has filtering support: https://azure.microsoft.com/en-us/blog/request-filtering-in-application-insights-with-telemetry-processor/
My team had a similiar situation where we needed to filter out urls that were successful image requests (we had a lot of these which made us hit the 30k datapoints/min limit).
We ended up using a modified version of the class in Sergey Kanzhelevs blog post to filter these out.
We created a RequestFilterChannel class which is an instance of ServerTelemetryChannel and extended the Send method. In this method we test each telemetry item to be sent to see if it is an image request and if so, we prevent it from being sent.
public class RequestFilterChannel : ITelemetryChannel, ITelemetryModule
{
private ServerTelemetryChannel channel;
public RequestFilterChannel()
{
this.channel = new ServerTelemetryChannel();
}
public void Initialize(TelemetryConfiguration configuration)
{
this.channel.Initialize(configuration);
}
public void Send(ITelemetry item)
{
if (item is RequestTelemetry)
{
var requestTelemetry = (RequestTelemetry) item;
if (requestTelemetry.Success && isImageRequest((RequestTelemetry) item))
{
// do nothing
}
else
{
this.channel.Send(item);
}
}
else
{
this.channel.Send(item);
}
}
public bool? DeveloperMode
{
get { return this.channel.DeveloperMode; }
set { this.channel.DeveloperMode = value; }
}
public string EndpointAddress
{
get { return this.channel.EndpointAddress; }
set { this.channel.EndpointAddress = value; }
}
public void Flush()
{
this.channel.Flush();
}
public void Dispose()
{
this.channel.Dispose();
}
private bool IsImageRequest(RequestTelemetry request)
{
if (request.Url.AbsolutePath.StartsWith("/image.axd"))
{
return true;
}
return false;
}
}
Once the class has been created you need to add it to your ApplicationInsights.config file.
Replace this line:
<TelemetryChannel Type="Microsoft.ApplicationInsights.WindowsServer.TelemetryChannel.ServerTelemetryChannel, Microsoft.AI.ServerTelemetryChannel"/>
with a link to your class:
<TelemetryChannel Type="XXX.RequestFilterChannel, XXX" />
Alternatively, you can disable the automated request collection and keep only exception auto-collection, just remove the RequestTrackingModule line from applicationinsights.config.
If you still need to collect some of the requests, not just filter all out, you can then call TrackRequest() (in the object of TelemetryClient class) from your code in the appropriate place after you know that you certainly need to log this request to AI.
Update: Filtering feature has been released some time ago and allows for exclusion of certain telemetry items way easier.
I have an MVC application in which I have a controller that receives data from the user and then uploads a file to Azure blob storage. The application is using Unity IoC to handle dependency injection.
During the workflow I have isolated the following code as demonstrating the problem
public class MvcController : Controller
{
private IDependencyResolver _dependencyResolver;
public MvcController() : this(DependencyResolver.Current)
{
}
public MvcController(IDependencyResolver dependencyResolver)
{
this._dependencyResolver = dependencyResolver;
}
public GetService<T>()
{
T resolved = _dependencyResolver.GetService<T>()
if (resolved == null)
throw new Exception(string.Format("Dependency resolver does not contain service of type {0}", typeof(T).Name));
return resolved;
}
}
public class MyController : MvcController
{
[NoAsyncTimeout]
public async Task<ActionResult> SaveFileAsync(/* A bunch of arguments */)
{
/* A bunch of code */
//This line gets a concrete instance from HttpContext.Current successfully...
IMyObject o = GetService<IMyObject>();
await SaveFileToAzure(/* A bunch of parameters */);
.
.
/* Sometime later */
Method2(/* A bunch of parameters */);
}
private Method2(/* A bunch of parameters */)
{
//This line fails because HttpContext.Current is null
IMyObject o = GetService<IMyObject>();
/* A bunch of other code */
}
private async Task SaveFileToAzure(/* A bunch of parameters */)
{
//Grab a blob container to store the file data...
CloudBlobContainer blobContainer = GetBlobContainer();
ICloudBlob blob = blobContainer.GetBlockBlobReference(somePath);
Stream dataStream = GetData();
System.Threading.CancellationToken cancelToken = GetCancellationToken();
//All calls to DependencyResolver.GetService<T>() after this line of code fail...
response = await blob.UploadStreamAsync(dataStream, cancelToken);
/* A bunch of other code */
}
}
Unity has a registration for my object:
container.RegisterType<IMyObject, MyObject>(new HttpLifetimeManager());
My lifetime manager is defined as follows:
public sealed class HttpRequestLifetimeManager : LifetimeManager
{
public Guid Key { get; private set; }
public HttpRequestLifetimeManager()
{
this.Key = Guid.NewGuid();
}
public override object GetValue()
{
return HttpContext.Current.Items[(object)this.Key];
}
public override void SetValue(object newValue)
{
HttpContext.Current.Items[(object)this.Key] = newValue;
}
public override void RemoveValue()
{
HttpContext.Current.Items.Remove((object)this.Key);
}
}
Nothing complicated.
Stepping into the HttpRequestLifetimeManager on the failing GetService() calls shows that after the UploadStreamAsync() call HttpContext.Current is null...
Has anyone else come across this problem? If so, is this a bug? Is this expected behaviour? Am I doing something out of the ordinary? What should I do to resolve it?
I can hack around it by storing a reference to HttpContext.Current prior to the offending call and restoring it after, but that doesn't seem like the right approach.
Any ideas?
To echo #Joachim - http context may not be available to your async thread. Compare the current thread id where you can see httpcontext is available, to the thread id where you can see that it isn't - i'm assuming you will see they are 2 different threads. If my assumption is correct this may be a sign that your main thread (the one with httpcontext) does not have a "synchronizationcontext". (you can see http://blogs.msdn.com/b/pfxteam/archive/2012/01/20/10259049.aspx for more details of how that works) If so, it may mean that the code immediately after your await statement is actually not running on the same thread as the code prior to the await statement! So from your perspective, one moment you have http context and the next you don't because execution has actually been switched to another thread! You should probably look at implementing / setting a synchronizationcontext on your main thread if that's the case and then control will be returned to your original thread with http context and that should fix your problem, or alternatively you could retrieve your object from http context on the original thread and find a way to pass it as a parameter to the async method/s so that they don't need to access http context to get their state.
I have the following (here simplified) code which I want to test with FakeItEasy.
public class ActionExecutor : IActionExecutor
{
public void TransactionalExecutionOf(Action action)
{
try
{
// ...
action();
// ...
}
catch
{
// ...
Rollback();
}
}
public void Commit()
{ }
public void Rollback()
{ }
}
public class Service : IService
{
private readonly IRepository _repository;
private readonly IActionExecutor _actionExecutor;
// ctor for CI
public void ServiceMethod(string name)
{
_actionExecutor.TransactionalExecutionOf(() =>
{
var item = _repository.FindByName(ItemSpecs.FindByNameSpec(name));
if (item == null) throw new ServiceException("Item not found");
item.DoSomething();
_actionExecutor.Commit();
}
}
}
I want to test that the ServiceException is thrown so i setup my test like that
var repo = A.Fake<IRepository>();
A.CallTo(() => repo.FindByName(A<ISpec<Item>>.Ignored))
.Returns(null);
var executor = A.Fake<IActionExecutor>();
executor.Configure()
.CallsTo(x => x.Rollback()).DoesNothing();
executor.Configure()
.CallsTo(x => x.Commit()).DoesNothing();
executor.Configure()
.CallsTo(x => x.TransactionalExecutionOf(A<Action>.Ignored))
.CallsBaseMethod();
With the following code
var service = new Service(executor, repo);
service.ServiceMethod("notExists")
.Throws(new ServiceException());
I get the following message
The current proxy generator can not intercept the specified method
for the following reason:
- Sealed methods can not be intercepted.
If I call the method directly on the service like
var service = new Service(executor, repo);
service.ServiceMethod("NotExists");
I get this message
This is a DynamicProxy2 error: The interceptor attempted to 'Proceed'
for method 'Void TransactionalExecutionOf(System.Action)' which has no
target. When calling method without target there is no implementation
to 'proceed' to and it is the responsibility of the interceptor to
mimic the implementation (set return value, out arguments etc)
Now I am a bit confused and don't know what to do next.
Problems comes from the way you create fake and what you later expect it to do:
var executor = A.Fake<IActionExecutor>();
// ...
executor.Configure()
.CallsTo(x => x.TransactionalExecutionOf(A<Action>.Ignored))
.CallsBaseMethod();
What base method? FakeItEasy has no idea what the base class is, and hence the DynamicProxy2 exception in your second case. You can create partial mock this way:
var executor = A.Fake<ActionExecutor>();
Note that we're basing on actual implementation, not interface anymore
This however introduces a new set of problems, as methods on ActionExecutor are not virtual and therefore interceptor cannot hook up to well - intercept them. To make your current setup work, you'll have to change your ActionExecutor and make (all) the methods virtual.
However, you may (or even should) want to avoid modifications of existing code (which sometimes might not even be an option). You could then set up your IActionExecutor fake like this:
var executor = A.Fake<IActionExecutor>();
A.CallTo(() => executor.TransactionalExecutionOf(A<Action>.Ignored))
.Invokes(f => new ActionExecutor()
.TransactionalExecutionOf((Action)f.Arguments.First())
);
This will allow you to work on faked object, with the exception of call to TransactionalExecutionOf which will be redirected to actual implementation.