Adding / Mocking JsFunctionalityService & IJSRuntime

[tenngs]

I am trying to add a JsFunctionalityService class as scoped to my Services in my test class. The constructor and fields of JsFunctionalityService look like this:

I have also added it to my Startup.cs like this:

When I am trying to write a test for a NavigationFrame component that has JsFunctionalityService injected using the below code, I am getting an error saying that my argument type in the test function is not assignable to the parameter in the test function.

I do not need JsFunctionalityService for anything (ie. I am not testing that itself), but I cannot run any tests because the NavigationFrame component that I want to write tests for cannot be rendered as bUnit says that "cannot register JsFunctionalityService as a service".

I have tried mocking JsFunctionalityService and IJSRuntime without success.

Could someone guide me as to what is going on here please and how I could register JsFunctionalityService as a service to write tests for the NavigationFrame component that I need to test. I would really appreciate it.

Many thanks.

[linkdotnet]

Hey @tenngs,

there are multiple ways you could achieve that. The first and easiest, do the same as in your production code:

Services.AddScoped<IJsFunctionalityService, JsFunctionalityService>();

No reason to new up the instance yourself - you have a container for this. Also the IJSRuntime is registered inside the container (by bUnit).

But I would suggest (because you said you do not need the service per see):

Services.AddScoped(_ => Mock.Of<IJsFunctionalityService>()); // Use your mocking framework

[tenngs]

Thank you for your amazingly quick response @linkdotnet !

I tried both of the approaches you mentioned, but I am still getting the same error: "Cannot provide a value for property 'jsFunctionalityService' on type xxxx.xxxx.xxxx.xxxx.NavigationFrame"
I am presuming that it is failing in this line in NavigationFrame:

Would you @linkdotnet (or anyone else) have any idea why that would be, please? I realise it is extremely difficult to say without seeing the files itself, but any nudge to any direction would be very much appreciated!

[linkdotnet]

Ah. Yes - your component should either use the interface version or register the instance.
So in your component do this:

@inject IJsFunctionalityService jsFunctionalityService

Or register inside your bUnit test the instance:

Services.AddScoped<JsFunctionalityService>();

Edit: In your test, you are only registering the interface, but the component is asking for the instance.

[tenngs]

@linkdotnet, thank you so much for your help! Everything works now. I was stuck on it about a day and a half!