Worth having SupplyParameterFromQueryAttribute support?

[linkdotnet]

.NET6 introduced the new attribute SupplyParameterFromQuery which basically allows to set a parameter from the query string of the url.

@page "/"

@MyCount

@code {
    [Parameter]
    [SupplyParameterFromQuery(Name = "my-count")]
    public int MyCount { get; set; }
}

Would display "3" if you pass the url http:localhost:12345/?my-count=3.
As it is a parameter we can currently define the value without any problem

var cut = ctx.RenderComponent<MyComponent>(p => p.Add(s => s.MyCount, 3));

Would it make sense to offer another method which is only meant for query parameters?

var cut = ctx.RenderComponent<MyComponent>(p => p.AddViaQueryString(s => s.MyCount, "http://localhost:12345/?my-count=3"));

Of course we'd have to raise exceptions in various conditions:

• The given parameter has not set the attribute
• Multiple parameters with the same selector
• The given query string does not match the Name part of the attribute (maybe with an overload where this is allowed and we default the given parameter)

[egil]

Hi @linkdotnet,

I did consider adding something to bUnit that would explicitly support that feature, e.g. perhaps an extension to the FakeNavigationManager, however, it did not seem worth the effort, because we can set the parameter ourself directly, and, for the most part, we would not be testing "our" code paths, but Blazors. I don't like to test code that is not mine, thus I decided not to build something into blazor.

If it was an important criteria for a component under test to have the attribute on a property, I would just write a test that verifies that attribute is on the expected property, and not test how the attribute is used by Blazor.