Skip to main content

Integration tests written in .Net using locally hosted node.js server

I've blogged before about hosting web services created with Web API inside a test fixture in .Net, what follows is the same idea but in this case hosting a node.js implemented web service, this is using the node.js server I created in this previous post.

Jumping straight to the solution this is what I came up with:
As you can I've managed to reduce the amount required to be specified for each test fixture to 3 parameters:

  1. working directory for node.js server,
  2. full path to the node executable, 
  3. node server name and any arguments (note the port number).
The implementation detail has been pushed into the base class - WebServiceIntegrationFixtureBase.

Before showing the implementation for this class, the test runner & fiddler outputs are shown below:
The base class implementation is shown below, as you can probably guess this uses the Process class from the System.Diagnostics namespace:
Loading ....
As you can see there isn't much going on, the main thing to notice is the use of an event handler for the Process class Exited event. This is done to check if the process starts up and remains running. The node server will return an exit code '8' if it fails to start the server correctly. The most likely reason this will happen is because the port the derived test fixture is using is already in use by another process, and if this happens I want to fail the test.

You might ask why bother?

I run my test using a continuous testing plugin like nCrunch and it's configured to run test simultaneously. This means if I'm not careful about the port I specify for each test they may clash and cause node to crash on start-up - in the example above I'm not worrying about this as there is only one test, but if there were multiple tests in the fixture I would be using some mechanism to generate a unique valid port number.


Comments

Popular posts from this blog

Implementing a busy indicator using a visual overlay in MVVM

This is a technique we use at work to lock the UI whilst some long running process is happening - preventing the user clicking on stuff whilst it's retrieving or rendering data. Now we could have done this by launching a child dialog window but that feels rather out of date and clumsy, we wanted a more modern pattern similar to the way <div> overlays are done on the web. Imagine we have the following simple WPF app and when 'Click' is pressed a busy waiting overlay is shown for the duration entered into the text box. What I'm interested in here is not the actual UI element of the busy indicator but how I go about getting this to show & hide from when using MVVM. The actual UI elements are the standard Busy Indicator coming from the WPF Toolkit : The XAML behind this window is very simple, the important part is the ViewHost. As you can see the ViewHost uses a ContentPresenter element which is bound to the view model, IMainViewModel, it contains 3 child v

Showing a message box from a ViewModel in MVVM

I was doing a code review with a client last week for a WPF app using MVVM and they asked ' How can I show a message from the ViewModel? '. What follows is how I would (and have) solved the problem in the past. When I hear the words ' show a message... ' I instantly think you mean show a transient modal message box that requires the user input before continuing ' with something else ' - once the user has interacted with the message box it will disappear. The following solution only applies to this scenario. The first solution is the easiest but is very wrong from a separation perspective. It violates the ideas behind the Model-View-Controller pattern because it places View concerns inside the ViewModel - the ViewModel now knows about the type of the View and specifically it knows how to show a message box window: The second approach addresses this concern by introducing the idea of messaging\events between the ViewModel and the View. In the example below

Custom AuthorizationHandler for SignalR Hubs

How to implement IAuthorizationRequirement for SignalR in Asp.Net Core v5.0 Been battling this for a couple of days, and eventually ended up raising an issue on Asp.Net Core gitHub  to find the answer. Wanting to do some custom authorization on a SignalR Hub when the client makes a connection (Hub is created) and when an endpoint (Hub method) is called:  I was assuming I could use the same Policy for both class & method attributes, but it ain't so - not because you can't, because you need the signatures to be different. Method implementation has a resource type of HubInnovationContext: I assumed class implementation would have a resource type of HubConnectionContext - client connects etc... This isn't the case, it's infact of type DefaultHttpContext . For me I don't even need that, it can be removed completely  from the inheritence signature and override implementation. Only other thing to note, and this could be a biggy, is the ordering of the statements in th